Historical atmospheric partial pressure & Henry's law constant The explanation given for the fact that temperature has historically led CO₂ levels is Henry's law.

Figure 1: Vostok ice core records for carbon dioxide concentration (Petit 2000) and temperature change (Barnola 2003), posted on www.skepticalscience.com.

However, no statistical evidence for the other Henry's law variables are ever supplied.

What are the historical Henry's law variables?

The source you mentioned tries to explain why CO2 lags by about 1000 years in historical records.
Henry's law tells you something about the equilibrium between the CO2 level in the surface layer and the atmosphere. However, this is not the reason for the 1000 year time-lag mentioned. There's not enough CO2 in the surface layer to cause these increases in atmospheric concentration. What is important is the exchange of CO2 between the deep sea and the surface layer. This seems to have a typical timespan of 1000 a.
Citing from your source:

  As the Southern Ocean warms, the solubility of CO2 in water falls (Martin 2005). This causes the oceans to give up more CO2, emitting it into the atmosphere. The exact mechanism of how the deep ocean gives up its CO2 is not fully understood but believed to be related to vertical ocean mixing (Toggweiler 1999). The process takes around 800 to 1000 years, so CO2 levels are observed to rise around 1000 years after the initial warming (Monnin 2001, Mudelsee 2001).

So the initial increase in CO2 levels due to Henry's law trigger via feedback mechanisms changes in the vertical circulation pattern thereby transporting more CO2 from the deep sea to the surface. It's this time constant that is seen in the records.


Are there any techniques for imaging the deep Earth besides seismic waves? It is well-known that we can learn a lot about the structure of the lower crust, mantle, and core by observing the ways in which they refract different kinds of seismic waves.

Do we have any other ways of imaging the deeper parts of the Earth, though?

Gravity can be used to investigate the lower crust and upper mantle (see for example Fullea et al, 2014). Satellite measurements of gravity could even be to investigate deeper structures in the mantle, like subducting slaps (Panet, 2014). However, I couldn't find any use of gravity data to probe deeper, into the core for example.

The magnetotelluric method is sometimes used for deep crustal structure. And features of the geomagnetic field, like secular variation, can be inverted to investigate as far down as the outer core (Gubbins, 1996).

However, the most common and well developed method to image the lower mantle and core is still through seismic waves.


Elevation of Atmosphere differ? Does the atmosphere depth (or how high the air molecules from the ground) of Earth or Mars differ gradually or can there be plumes of atmosphere that reaches into space? If I were able to travel a perfect circle around the equator would the atmosphere differ in elevation?

The atmosphere has various layers.  Going upwards they are - troposphere, stratosphere, mesosphere, thermosphere, exosphere. (There are "pause" layers between, like tropopause, stratopause etc.) The density gets less and less and the exact height to the top of the exosphere is difficult to determine because the gas is so thin. However, we normally talk about the height of the troposphere which varies from about 7 to 10 km at the poles to about 18 km above the Equator. The reason it is higher at the Equator has to do partly with centrifugal force being greater there. For example, if a jelly-like sphere is rotated it starts to bulge outwards in the central, faster moving region.  Even the solid Earth itself bulges at the Equator due to centrifugal force.  See this blog post for details.


Why do crystals, like quartz and diamonds, form in different colors? Some crystals, like quartz and diamonds, form in a variety of different colors. For example, quartz can be clear, 'foggy', pink, yellow, and even blue.

What happens during the crystal's formation to make it one color or
another?

The reason minerals like quarts and diamonds vary in color is generally caused by the chemical elements involved while the crystal is being formed.

Chemicals
Different colors can be created by different chemicals. Amethyst for example has traces of iron built into its crystalline structure giving it a purple hue. Iron can also give crystals a yellow hue.

[edit: See Gimelist's answer for a much more detailed and colorful explanation]

Growth Imperfections
Some colors, like in smoky quartz, are from growth imperfections. These imperfections change the way the crystal reflects light, which changes the appearance of coloration.

Light
Part of the color seen when looking at a crystal is light. When light enters a crystal its spectrum is broken apart, and part of it is absorbed while other parts are reflected. This changes the apparent color of the crystal.


Gravitational Anomaly of a subsurface body How does the gravitational anomaly measured at the Earth's surface and produced by a subsurface body depend on its depth and on the density contrast of the body relative to its surroundings?

The gravitational anomaly (delta_g) changes linearly with the density contrast, and proportionally to the inverse square of depth. That's simply a version of the 'Universal Law of Gravitation'.
Here is an example for the anomaly created by an spherical anomalous spherical body with a density difference of delta_rho relative to the surrounding density. G is the known Gravitational Constant:

From Turcotte and Schubert, 2002, Geodynamics


Significant difference between averaged wind speeds and averaged wind power density, for wind generation modelling? Climate models outputs, particularly the reanalysis datasets, output wind speeds as zonal and meridional averages for the modelled time period (typically 1, 3 or 6 hours). So we get a 2-dimensional vector, the U and V values, each of which is signed. Together, they give us a mean wind speed, and a mean direction.

There are some oddities there, as I understand it. If the wind within one interval were 9 m/s due East for half the time, then 9 m/s due West for the other half, then the UV values would be (0, 0). That's a very contrived case, just to illustrate the netting off for any wind that switches sign on either the U or V directions.

Some reanalysis datasets fix this part of the problem by giving mean wind speeds as well as mean UV components.

But for the estimation of wind electricity generation , what we really need are the mean power densities ($\mathrm{W/m^2}$ in the vertical plane) of wind, at turbine hub height (typically 80m or so). That way, we can multiply the swept area of the blades, by the mean power densities, and combine with a modified version of the turbine power curve, to estimate electricity generation.

Now, the relationship between wind speeds and power densities is cubic. But the average of a cubed value is not the same as the cube of the averaged value. So, taking the cube of average wind speeds is not the same as taking the average of the cube of wind speeds. And then there's the possibility of positive or negative correlations between wind speeds and atmospheric pressure, which would also mess with the averaging.

Is there an analysis of the impact of these distortions on our ability to model & predict wind power generation?

In ECMWF data, wind direction and wind speed are collected from observation separately. Then based on a well known transformation the wind vectors, u and v are calculated.

Their documentation: http://www.ecmwf.int/sites/default/files/elibrary/2015/9208-part-i-observation-processing.pdf

You can focus on this part in their documentation:

" **Wind.**There are four wind variables: wind direction(DDD), wind force(FFF),u and v components. For each of these variables the first thing which is done is to get a local copy of it together with its related parameters from an ODB supplied array (GETSETE).Once a variable is made available locally a check is made to ensure that the vertical coordinate is pressure; if instead of pressure a flight level is supplied it is converted into pressure by assuming a standard ICAO atmosphere(Z2PICAO). If the variable in question is either u or v, then DDD and FFF are converted into u and v wind components. Furthermore, for each of the four variables appropriate observation error statistics are assigned (ERRSTAT, FINOERR). Also, if any flags are set at this stage an appropriate word in the local copy is updated (PPVAFL). Finally, an updated local copy of an observed quantity and its related parameters are returned back into the ODB (AIREPBE)."*

Once wind speed and direction are obtained calculations are made to get the two components of wind u and v.
e.g.
    $$u = -FFF sin(DDD \frac{\pi}{180})$$
    $$v = -FFF cos(DDD \frac{\pi}{180})$$

In calculating wind power, we need wind speed and not wind direction. If we are given u,v components of wind, we can calculate wind speed as
$$ U = \sqrt{u^{2} + v^{2}}$$.
Then, the power density,
   $$ P = \frac{1}{2}\rho A U^{3}$$
To sum up when we calculate wind power, what we need is the speed and not the direction.

This may not answer your question but I hope it may give some hint about it!


What are the geological mechanisms for sea floor spreading in the Bismarck Sea? The North and South Bismarck microplates (north east of Papua New Guinea) are separated by a ridge of sea floor spreading, as described in Oregon State webpage as

  The tectonics in this part of the world is very complicated. A spreading center creates the North and South Bismarck microplates. The Pacific plate is subducted under the North Bismarck Plate. The Solomon Sea microplate is subducted under the South Bismarck microplate.

And shown in the diagram below (from the same source):

What are the geological mechanisms that cause this area of sea floor spreading in an area dominated by subduction processes?

Ah yes, this is a very good question. The formation of back-arc spreading centers is an open research problem, and happens to be the main topic of my office mate's dissertation! While these aren't exactly "clean" back-arcs, the formation of them is similar, I'm fairly sure.

The formation of back-arcs is caused by "Trench Roll-back". Trench Rollback is where the trench is pushed back in the opposite direction of the subducting slab and causes extension in the back-arc, forming a spreading center.  Below is a diagram from Modeling the dynamics of Subducting Slabs, Magali Billen, Annual Reviews of Earth and Planetary Sciences, 2008:

You can ignore the "Shallow" vs "Deep and Wide Box" comparisons, those only matter for building a modeling domain. What is important is noticing what happens to the slab when it hits the 660km boundary: it has a much more difficult time subducting. The slab "glides" through the upper mantle, but deeper in the earth, the mineralogical phase changes make the mantle much denser, creating a much stronger normal force on the slab. This normal force transfers energy into the slab and "pushes" back causing a drag between the deeper slab and the slab in the upper mantle. Since the under-riding plate and the overriding plate are weakly coupled viscously, only a small portion of the overriding plate is pulled with the trench. This causes extension/rifting.

Not all subduction zones have a back arc: weaker slabs tend to have a much harder time forming one as the transfer of energy in a strong slab is much more efficient.

It is also important to note that these phase changes are currently the leading theory, but our dynamic models have a hard time dynamically developing trench rollback. Sure, the literature might sound optimistic about it, but thats with surface kinematic boundary conditions and not pure dynamics.

These rifting centers form from trench roll-back. We can measure this roll-back with GPS. What causes trench roll-back is a much harder question to answer, in my opinion.


What is this geomorphological form? What is this geomorphological form located at Vitrolles, France?

And how is it formed? It is like a 'raised flat land', or a base of a hill where the top 80% is cut, leaving only the wide, flat base.

There are a couple of possibilities, depending on what you're paying the most attention to.  This falls in an overlap area of terms that vary from region to region and even from person to person.

The key thing to notice in your photo is the whitish band running along the top of the escarpment that borders your landform.  This shows that it's held up by a resistant, mostly horizontal, layer of sedimentary rock.

This French page refers to it as a cuesta; this is plausible, but the strata underlying cuestas usually slope more than what appears in your picture.

(generalized cuesta image from Wikipedia)

"Plateau" is also plausible, but this is not very specific. The landform in your picture doesn't have quite the extent of the Colorado Plateau.

Tableland or table is probably the most generic name for the entire regional structure under the rock layer.

If you are talking about the remnant under the pin in your image (and especially if this were in America),  then we'd have no trouble calling it a mesa or even a  butte.

(Wikipedia image of a mesa in Monument Valley)


Does the elliptical orbit of the Earth have effect on Earth's climate? I know the Earth is nearest to Sun during the summers of the southern hemisphere. Does the orbit affect the climate actually? For example, would there be any difference if the Earth had a perfectly circular orbit?

If so, what is the effect of it? For example, does it cause hotter summers in southern hemisphere, or would it cause the southern hemisphere to receive more solar UV radiation?

Short answer.   When the Earth is closest to the sun in January that softens the seasonal variation in the Northern Hemisphere and it increases the seasonal variation in the Southern Hemisphere, so for now, in the Northern Hemisphere, the Summers are colder than they would be with a circular orbit and the winters are hotter.   The opposite is true in the Southern Hemisphere.

Overall the eccentricity variation doesn't change how much solar energy hits the Earth by much, so it's not the total solar energy.   It's when combined with precession, and the effect on the seasons, that the global effect can be significant.

If we had a perfectly circular obit then the only Milankovich cycle that would matter would be axial tilt.  Ice ages would either be on a 41,000 year cycle - very neat and tidy, or they wouldn't happen at all cause the orbital variation wouldn't be enough to get ice ages started.  Other factors, like solar minimums could play a role and over longer periods of time, continental drift and variations in plant life, so, maybe not that exactly that, but I think it's likely.

Too long answer:   Hotter summers and colder winters (or the opposite) is a form of climate change that accompanies the orbital cycles.  All the orbital cycles change climate at least by seasonally.  But if I'm reading your question right, you're asking about global temperature, not just seasonal variation.

Eccentricity has an effect because the two hemispheres are quite different and because it amplifies the effect of precession.

Oceans tend to be a temperature buffer.  They circulate and they warm up slowly and they cool down slowly so they don't get too hot in summer or too cold in winter.  Land can vary in temperature significantly more.   This buffering can be seen in this average temperature chart of the two hemispheres.

The Northern Hemisphere varies about 13 degrees C and the Southern about 5.5 C.   Those numbers might seem low, but remember that near the equator, seasonal variation is small and there's more land near 0 latitude than up near 90 or -90.   How accurate this chart is, isn't really relevant.   It doesn't need to be perfect.  What's relevant is that seasonal variation is much smaller in the Southern Hemisphere because so much of it is ocean, even with the Sun being closest in January which should make the Southern Hemisphere season variation more extreme.  The ocean is the key factor.

With that in mind we can ignore the smaller variation in the Southern Hemisphere and just look at the Northern Hemisphere variation for any orbataly driven climate effects.   Before we get into eccentricity, it's important to understand Axial Precession.   The Earth, as you noted, is closest to the Sun in early January, January 4th this year.  that 3.4% closer That means Earth gets nearly 7% more sunlight in the first week of January than it gets in the first week of June.   That 7% is too small to move the seasons, but it's enough to affect them a bit.   Earth overall gets more solar energy January (Northern Hemisphere Winter) and less solar energy in June.   The Northern Hemisphere's more exteme seasonal variaiton comes into play when the Earth is closest to the Sun in May-June-July-August - that should happen in about 8,000 years, give or take.  The cycle averages about every 23,000 years, so roughly 11,500 years between highs and lows for each hemisphere.

The most relevant factor is the Northern Hemisphere Summer.   This is what is thought to drive ice ages back and forth.   Snow can last on land a long time in higher Northern latitudes and when the summers are less hot, the snow can last well into May, June, even all year around.   The warmer winters are less of a factor cause you still get snow in warm winters, sometimes, it snows more heavily when the winter is warmer.    It's the cooler Northern Hemisphere Summers that allow snow build-up and make ice ages possible.  Eccentricity (combined with precession) plays a key role on the periodic, colder Northern Hemisphere summer.

Don't worry, we're not entering an ice age in a few thousand years.   We're actually in a cool Northern Hemisphere summer period now, but, It's not quite that automatic.

The eccentricity in effect, determines how significant the axial precession is.   When the orbit is nearly circular, the difference in energy perihelion to aphelion is virtually zero.   Orbital eccentricity is currently dropping, moving towards circular, so we're not in a period of expected significant changes.  (The increased CO2 would prevent an ice age now anyway, but that's another story).  Earth's orbital cycles are in more of a holding pattern than moving towards an ice age.

When eccentricity peaks, the variation in solar energy hitting the Earth, perihelion to aphelion is significant.   It's loosely speaking, about 4 times the eccentricity.  The current eccentricity is 0.017, the current variation, Early January to Early June is about 4 times that or 0.068 or 6.8%.   At peak eccentricity of about .0679 would work out to roughly 27% variation in solar energy hitting the Earth, Perihelion to Aphelion.  (Perhaps nearly 30% with the working out the square).   This 30% variation in solar energy, depending on the perihelion and aphelion fall on the calendar, is sufficient to make ice ages come and go.   ((For very high eccentricity this 4 times rule doesn't work, but it applies pretty close to eccentricity pretty close to 0.))

In laymans terms, think of the eccentricity as turning up or down the effect of axial precession and those two combined, when properly lined up with the hemispheres, have a significant effect.

The 3 cycles together, make a kind of ugly chart of ups and downs.  The orbital effect is rather uneven but Ice ages are often periodic because of feedback mechanisms on Earth.  Once formed, Glaciers are hard to melt and once melted, it takes peak conditions to get them forming again, so many of the smaller ups and downs in the chart don't drive ice ages, only the extremes.

Wikipedia has a nice graph on the Northern Hemisphere solar energy at summer solstice.   When the chart is high, that tends to be a period of glacial melt.  When it's low, that's a period of ice age formation.

Because the eccentricity is currently kind of low and shrinking, we're probably not due for an ice-age for about 50,000 years, at least according to current orbital models, per Wikipedia (same link as just above).


How does the Coriolis effect affect rivers and estuaries I'm quite confused about this since it is said to influence major currents in the sea the winds to the formation of gyres in the ocean and as well as influencing the weather at times due to the planet's rotation and the direction of where the winds are going.

Are there any effects(positive/negative such as sudden algal blooms) generated by the Coriolis effect that can affect the rivers and the inhabitants near it?

The effects of Coriolis in rivers and estuaries are more subtle than in the open ocean. Coriolis tends to be a second or third order process in fast-moving and relatively small systems like rivers.

On the other hand, when the residual flow in an estuary is considered, then that process tends to be slow and persistent and the effects of Earth's rotation (Coriolis) can be more obvious. The residual flows tend to be much weaker than tidal flows in estuaries. Both seaward and landward residual flows are going to be slightly displaced to the right of the direction of flow (in the northern Hemisphere) resulting in asymmetric flows. The resulting exchange flow (in the northern Hemisphere), looking in up-estuary direction, is going to have denser seawater flowing into the estuary in the deeper right side of the estuary, while fresher (lighter) river water will tend to flow seaward near the surface along the left side of the estuary.

 Source GSO-URI.

The asymmetric flow exchange will affect any particle in suspension (e.g., organisms, sediment). In general, estuarine circulation tends to create areas of high turbidity (estuarine turbidity maximum, ETM) in the vicinity of the tip of the salt wedge. Decomposition of organic material in the high turbidity zone of the ETM can cause oxygen depletion, especially in the lower part of the vertical where mixing with oxygen-rich surface water is inhibited by stratification. In a system where Coriolis is a relevant factor, the distribution of this anoxic conditions (the often called "dead zone") is going to be displaced and can be more extensive in the right side of the estuary.

 Source: Columbia River Estuarine Turbidity Maxima

A good summary of the effects of rotation (Coriolis) in estuaries can be found in Valle-Levinson (2011).

  Valle-Levinson A (2011)  Large Estuaries (Effects of Rotation). In: Wolanski E and McLusky DS (eds.) Treatise on Estuarine and Coastal Science, Vol 2, pp. 123–140. Waltham: Academic Press.


Why would volcano eruption cause cardiac arrest? Following recent eruption of Mt Ontake and the sad news of over 30 people found in 'cardiac arrest', why would the eruption cause it?

My initial thought would be that the cause of death would normally be suffocation or burns from the hot ash. Is it to do with elements/compounds present in volcanic ash?

Michael's comment is correct, in Japan, according to the article Japan volcanic eruption: Mt Ontake rescuers find more than 30 people in 'cardiac arrest' (Radio Australia), state

  Police said the 31 people were found in "cardiopulmonary" arrest on Sunday but declined to confirm their deaths pending a formal examination, as per Japanese custom.

and more directly, from More than 30 feared dead on Japan's Mount Ontake after volcano erupts (Washington Post)

  using the terms for heart and lung failure that Japanese authorities employ to describe bodies. People cannot be declared dead in Japan until doctors have examined them.

It is very likely, given how close they were to the eruptive crater and the sudden inhalation of hot volcanic ash, gases and other materials, the victims went into cardiopulmonary arrest due to their lungs being overwhelmed by the sudden quantity.  Additionally, burns, fear, debris could have likely caused shock causing cardiac arrest.

Several case studies from other volcanoes are presented in the article The respiratory health hazards of volcanic ash:
a review for volcanic risk mitigation (Horwell and Baxter, 2005).


Is the sea level rise unusual? I'm discussing climate change with a friend who is a climate change denier, basically the argument is that looking at this graph, is not clear that something unusual is going on, so the sea level rise is just something that was there, all natural not caused by human activity. Could you please explain this ?

The problem is the increase in the rate of sea level rise. I pulled out some approximate numbers from the figure you presented:

Can you see now how the sea level is rising much faster today than a century ago?

Sea level rise, as well as climate change are normal things on Earth history. However, most times they happen at a very slow rate, allowing ecosystems and other processes to adapt to the change.

For example, if the climate changes over several hundreds of years, animals and even tree populations can "move" towards the side of their distribution where climate is still good for them. But if the climate changes in 50 years, all the trees can die before they had time to grow in the areas where they could thrive in the new climate.

In the case of sea level rise. The delta of a river for example, stays in equilibrium with the sea level because of the accumulation of sediments carried by the river. If the sea level rises slowly, the sediments can fill the delta and keep it roughly at sea level. But if the see level rises too quick for the sedimentation to keep up, it will be flooded by the sea, killing all the animals and people that live on such fertile environments.

Analogously, coastal infrastructure have a given lifetime. Let's say 50 years. If the sea level doesn't change much over that period (8.5 cm at the 1880-1940 rate), there is no problem. Once the infrastructure gets replaced, the new building will be set a bit higher.
However, in the next 50 years the sea level could rise 50 cm, or even more (it would be 19 cm if we assume the last rate from the figure won't increase any further), and that is a big deal. That could mean that much coastal infrastructure will be flooded, and maybe destroyed during storms.

In places like Bangladesh there are hundred of millions of people that could be displaced due to sea level rise if the rate keeps increasing. People that will also need to find a new home.

Coastal infrastructure loss, coastal erosion and immigration could be some of the worst expressions of fast sea level rise.

ADDITION

Given the interest risen by this question I'm adding here some data beyond what is presented by the OP, and brought to my attention by @Bobson in the comments. It comes from the paper Recent global sea level acceleration started over 200 years ago? and shows a sea level reconstruction going back to 1700, and it shows also the changes in rate over that period. This is summarized in their figure 3:

Here you can clearly see how, with some ups and downs, the rate of sea level rise have been increasing over the last few centuries. And notably the current rate, about 20 years after the end of this plot is already out of the scale, and around 3.2 mm/year as pointed also by other answers.

I would highlight the following from their abstract:

  Sea level rose by 6 cm during the 19th century and 19 cm in the 20th
  century.Superimposed on the long-term acceleration are quasi-periodic
  fluctuations with a period of about 60 years. If the conditions that
  established the acceleration continue,then sea level will rise 34 cm
  over the 21st century. Longtime constants in oceanic heat content and
  increased ice sheet melting imply  that  the latest
  Intergovernmental Panel on Climate Change (IPCC) estimates of sea
  level are probably too low.

Regarding to whether this is caused by humans or not, I rather stay out of that argument and point that our best science and models suggest that lowering $\text{CO}_2$ emissions can make a significant impact in slowing down sea level rise in the upcoming centuries, so we should ACT NOW, and stop arguing whether it was or not our fault in the first place.


Main sources of $\ce{CO2}$ emission to the atmosphere What are the main sources of $\ce{CO2}$ emission to the atmosphere? I know that the answer would probably be from the electricity sector and transportation but wouldn't most of the carbon dioxide produced from power plant be captured and stored by the CCS technology? Is it because not all the plants has the CCS technology to capture the $\ce{CO2}$? Or are there any scenario where CCS technology cannot be used e.g cars?

These are from the EPA's site for 2013. The top is USA emissions and the bottom, global.  I guess that's the most recent year for which they have complete results. And you're right; electricity and transportation account for 58% of total CO2 emissions.

The site is available here.


How do I find the volume of ocean between any two layers of ocean depth? I'm interested in this problem because I'm interested in obtaining a rough estimate of the average temperature increase of the sea given a net radiative forcing of 0.6 W/m^2.

But in order to obtain an estimate, I need to know the volume of the ocean between 0-2000m. I'm also interested in knowing the volume of the ocean between any other two arbitrary layers of the ocean (0-1000m, 1000-2000m, 0-4000m, etc..)

You can find gridded topography and bathymetry data, freely accessible, on the website of the NOAA. For instance you have the ETOPO1 dataset here.

Once you downloaded it you can work it out with your favourite GIS software or GIS-supporting programming language.

The equations to calculate the volume based on the gridded cells is given on this page from the NGDC website.

  Volume Calculation

  Volumes were calculated for each ocean grid cell in ETOPO1 using
  Equation 1 to determine cell area, and Equation 2 to determine cell
  volume. Cell areas and volumes were then summed over each ocean or
  marginal sea.

  Equation 1: $dA = \frac{a^2\cdot cos(ø)\cdot (1-e^2)\cdot dø\cdot dl}{(1-e^2 \cdot sin^2ø)^2}$
  Equation 2: $dV = dA \cdot depth$

  where:
  Latitude (ø)  = latitude of cell's center (in radians)
  Unit of Latitude (dø) = 1 arc-minute ($2.908882 \cdot 10^{-4}$ radians)
  Unit of Longitude (dl)    = 1 arc-minute ($2.908882 \cdot 10^{-4}$ radians)

  The WGS84 spheroid was used for values of Earth's radius and
  eccentricity:
  Equatorial radius (a) = 6378.137 km
  Eccentricity (e)  = 0.08181919


Implications of recent 36 degrees Fahrenheit (20C) anomaly at North Pole? This extreme difference from normal -- could it occur in climates that are warmer, making some places unlivable?

Additionally, is there a reason why extremely cold places should expect to have relatively warmer anomalies than climates that are warmer on average?

Source: http://www.sciencealert.com/the-north-pole-is-36-degrees-hotter-than-it-should-be-right-now

The specific 36 F temperature anomaly in the linked article points to a single day event. I am aware that it is associated with unusually high temperatures in general this fall/winter, but a single day event is not that unusual. For example, the average January temperature in Dallas is 46 F, and the average monthly high is 76 F. That means every year (on average) sees a temperature that is 30 F above normal. The record high in January is 88 F, meaning that at least once, the temperatures in Dallas were 42 F above normal. That was all the way back in 1969.

While this doesn't look great for the polar bears, and is further confirmation that AGW is coming along nicely, I would caution against getting too upset about it in the short term. We aren't out of time yet. After all, the world didn't end after that record January heat in 1969.


Fictional Land - How can I keep dense fog in an area for half a day? This question is now here on Worldbuilding Stack Exchange

I am a writer, and this question is for a fictional work. However, given its nature, I believe it is better suited here than Writers Stack Exchange.

In my fictional world, I have an area that is supposedly covered with fairly thick fog during most of the night and nearly all of the morning (it can leave a bit before noon if necessary). My question is this: What factors would I need to achieve this effect?

Factors:
It is a fantasy world, so the factors need to be natural. The area is within a city, and is very densely inhabited. The area is enclosed by large trees, and large roots run all over the ground. The fog does not need to reach any higher than 7 feet, but it does need to cover nearly the whole area (a generous approximation would be 288 ft by 228 ft - about 65,000 square feet). The walls of the area (giant roots/tree trunks) vary in distance from each other a lot.

Let me know if you need more details on the surroundings.

The heat of the Sun can "burn off" fog. So a lack of direct sunshine, cool temperatures & humidity (evaporation of water from a nearby body of water or saturated or wet ground) are key to maintaining fog. The air must be moist!


Do fossil fuels insulate the crust from the Earth's interior? I was doing a project for my English class, and I came upon the article Energy conservation in the earth's crust and climate change. I can't view the full text of the article, but the abstract piqued my interest:

Do long hydrocarbons in the earth actually have a significant effect in insulating the surface? Also, has the lack of these hydrocarbons resulted in any significant warming of the Earth thus far?

Quoting from John Russell's response to this article, "This is arrant nonsense!"

Russell concludes with

  How did this paper get through the peer-review and editorial review processes? What technical standards were applied to determine the apparent merit of its contents so as to justify its inclusion in a reputable journal?

Just because something is published in a scientific journal does not mean it is fact. Publication is where science starts rather than ends. Sometimes, pure garbage manages to slip through peer review and get published, even in reputable journals. This is one of those times. Moreover, the publisher of the underlying journal, Taylor & Francis, has had issues with shoddy peer review.

The Earth's energy imbalance is 0.6±0.17 W/m2. The Earth's internal energy budget, the amount of energy that escapes from the interior of the Earth, is 0.087 W/m2, about half the uncertainty in the Earth's energy imbalance. (That largish uncertainty is because the imbalance is a difficult quantity to measure.) Even if all of that 0.087 W/m2 is due to humans removing the Earth's insulating layer of hydrocarbons (it isn't), it does not come close to accounting for the 0.6±0.17 W/m2 imbalance. The numbers don't add up.

Or as John Russell put it in his response to the referenced article, "This is arrant nonsense!"


Impact craters vs volcanic explosions on Mars A maar is a shallow volcanic crater with steep sides that is surrounded by tephra deposits. The tephra deposits are thickest near the crater and decrease with distance from the crater.

Source: http://geology.com/stories/13/maar/

I have looked at about 70 craters formed by this type of explosion. I have gathered several data points such as diameter, depth, and elongation. I am now trying to use this data to attempt to find this type of crater in some regions of Mars.

Earlier attempts have ended in failure. Mainly because I am mistaking maar craters with supervolcanos, and impact craters with maars, and vice versa. The craters that I have looked at are very young. Mars's volcanic activity is believed to have ceased many billions years ago.

What are some good ways to identify this type of geologic feature from other potential doppelgangers? I have no data points for old maar craters mainly because they are too eroded to measure anything, and/or have large scoria cones that have erased their once-elliptical shapes.

In addition to Gordons approach it might be possible to differentiate between impact and volcanic craters by comparing the characteristics of the ejecta [1]. The apparent thermal inertia (defined for example in [2]) seems to be higher around volcanic craters [3]. Unfortunately the linked papers about the method are conference abstracts about ongoing research and I did not find a paper where they try to apply the method to remote sensing data from mars.

[1] Peet, V. M., M. S. Ramsey, and D. A. Crown. "Comparison of Terrestrial Morphology, Ejecta, and Sediment Transport of Small Craters: Volcanic and Impact Analogs to Mars." 36th Annual Lunar and Planetary Science Conference. Vol. 36. 2005.

[2] Putzig, Nathaniel E., and Michael T. Mellon. "Apparent thermal inertia and the surface heterogeneity of Mars." Icarus 191.1 (2007): 68-94.

[3] Peet, V. M., M. S. Ramsey, and D. A. Crown. "Remote Sensing Analyses of Small Terrestrial Volcanic and Impact Craters: A Mars Analog for Formation, Morphology, and Erosional Processes." Lunar and Planetary Science Conference. Vol. 38. 2007.


What is the origin of the dominant atmospheric nitrogen content in Earth's atmosphere? Comparing the atmospheric compositions of Earth with our nearest neighbours:

As the table shows, the Earth's atmospheric nitrogen concentration is 78%, compared to 3.8% for Venus and 2.7% for Mars Image source.

I have read the excellent question and answer Why do Earth and Venus have different atmospheres?, but the answer focuses on the $\ce{CO2}$ content of the planets, this question is about the $\ce{N2}$ content. Also, have read Why do some planets have lots of $\ce{N2}$ and others none?, but in this question, I am looking at how nitrogen concentrations dominated over the other chemicals in Earth's atmosphere, not looking at similarities between planetary processes.

In modern Earth, the nitrogen cycle maintains nitrogen levels, however the early pre-biotic atmosphere, was believed by

  most of the scientific community now believes that the early Earth's atmosphere was not reducing. Instead, scientists beleive the atmosphere was full of oxidants, such as $\ce{CO2}$ and $\ce{N2}$.

Source: Duke University Pre-Biotic Earth webpage

What is the origin of the dominant atmospheric nitrogen content in Earth's atmosphere?

According to the recent paper in Nature Geoscience: Nitrogen speciation in upper mantle fluids and the origin of Earth's nitrogen-rich atmosphere, $N_2$ originates from regions of the Earth where plates are converging.  Venus and Mars lack plate tectonics and therefore lack $N_2$ in their atmospheres.  In other regions of Earth upper mantle, and in Venus and Mars, nitrogen is expected to exist as aqueous ammonium and not enter the atmosphere.


Is this XKCD comic an accurate timeline of the earth's average temperature? Apologies for the length of the image, which I found at http://xkcd.com/1732/.
I'm mostly interested in the temperature line itself, both the historical data and the forward projections.
The reason I ask is that I'd like to (in a classroom context) hold this image up as a good example of the visualisation of data, that could be emulated in the area of science relevant to that classroom (zoology). However, I'd first like to check that the data itself is correct.

(click to enlarge)

Yes, it's accurate, see e.g. this picture taken from the Wikipedia Geologic temperature record page:

You could dig up the source if you wanted from the wikipedia article (or the graph description page), but any graph will be generally the same. Since there was an ice age, you'd expect global temperature to be low ~20k years ago and so on.


What could the ball of cloud I saw be? I wish I had a picture of this thing I saw, and I did try to video it, but then they hurtled very quickly out of sight.

Anyway, I will try to explain. . .

You know when you're up in a plane in the sky, you can see clouds in 'individual' balls? Well, it was about to rain yesterday and the sky was dark. Then suddenly I could see something like a very big, dirty, semi-transparent ball of cotton wool-like cloud hurtling towards me and over my roof. Then another, and then another. By the time I ran outside to try and video them, I could only see one very far off and it was going in a different direction.

The thing about it was that it wasn't like the entire mass of clouds moving across the sky, but it was like balls of clouds or gas, and they were just stumbling across the sky like they had been detached and blown away. And they were not looking nice or anything, but like a pocket of bad gas or something.

I have very little knowledge of science and I wonder if anyone is familiar with and can tell me what I saw?

It's hard to visualize exactly what you saw, but typically in convective clouds, there is such significant motion that oftentimes very chaotic and varying cloud shapes will develop as a result, and they may move quite quickly due to the strong winds.  It appears the term pannus may be used for these, though I'm more familiar with calling them scud.  You mentioned rain, it's northern hemisphere summer, so these cumulus-convection byproducts sounds quite likely.

Around other storm chasers/meteorologists, I've also heard these types of clouds called debris clouds... which is a rather apropos description given that such clouds are often leftovers from earlier storm evolution (perhaps even remnants of old wall clouds if in a situation with supercells)... but using that term might bring confusion to others because tornado debris can also be called a debris cloud.  This page appears to exemplify the confusion, as the picture appears to include remnant clouds from earlier storms in the foreground while the description gives the tornadic definition.  So we probably should avoid this term.

There's no bad gas in thunderstorms... what you see in meteorological clouds is liquid or ice water (all clouds form around tiny bits of dust and such, but this wouldn't affect appearance).  Occasionally smoke or such may be ingested in a cloud, but even in situations where large fires and volcanic eruptions produce clouds, the forced moist updraft region will often look quite similar to a typical cumulus cloud.


How deep could the Vredefort asteroid have penetrated? The asteroid which created the Vredefort impact crater in South Africa is estimated to have been between 10 and 16 km in diameter (the uncertainty is due to the age of the crater, which is more than 2 billion years).

Assuming the maximum estimate is correct, how deep could this asteroid have penetrated into the Earth's crust, and would the resulting crater have become filled or partly filled with magma like some of those on the moon?

The reason no mass extinction is associated with it is that at that time the most complex life on Earth was only single-celled. It should be remembered that the crust was thinner in those days, as was the case with the magma-filled craters on the moon.

Another important factor is the sped of the asteroid at the moment of impact, which we cannot know,therefore an average of mega-meteorite velocities will do. It is important to read this question carefully before answering,otherwise I have to keep repeating myself.

10–16 km

there is an interesting equation that demonstrates an rocky impactor hitting rock does not penetrate further than its diameter. Basically because a meteorite and the rock it hits have similar density several things cancel out so depth of penetration maxes out at the diameter of a spherical projectile.

Source

Source 2

image from Wikipedia.

Here is more about impact craters in general.
https://www.lpi.usra.edu/publications/books/CB-954/chapter3.pdf

Whether it hits on land or the ocean does not matter much either, although oceanic crust is thinner it is also denser, the mantle is even denser still so if it reaches the mantle it should penetrate even less than it would penetrating only crust. That said oceanic crust is only 5-10km in thickness so reaching the asthenosphere is completely possible.

Also keep in mind the depth of a crater is different than the depth of the penetration, a penetrator can generate a temporary crater deeper than it penetrated due to shockwave deformation, much like how a you can use your finger to push a depression into a balloon without penetrating it at all.

Would it fill with lava absolutely (at least partially) , just from the local rock melted from the impact alone.


What disciplines of science are used in the locating and extraction of mineral resources? Im trying to do an assessment but I just can answer this question!

The locating and extraction of mineral resources is essentially a three step process - find, extract and process.

The first step of finding the mineral resources requires the use of geophysics, geochemistry, sometimes geobiology and geology.

Geophysics uses techniques such as magnetic studies, geological resistivity and seismic analysis to find geological anomalies. Which techniques are used depends on the minerals sought (metal sulphides or oxides), the overall host geology of the region, the remoteness of a region and proximity to infrastructure.

Geochemistry generally involves taking multiple surface samples for chemical analysis over an area of interest to ascertain if there are any geochemical anomalies. One that comes to mind is following gold samples up a river to locate the hard rock source of the gold.

Geobiology is the use of plants to locate, or discover, a mineral deposit. One example that comes to mind was the discovery of the Viscaria copper deposit in Sweden due to a particular flower that grew over the deposit and not anywhere else in the region. The deposit was named after the flower that lead to its discover - Viscaria alpina (Lychnis alpina, "copper flower"). Geobiology is not widely used.

Geologists follow up any interesting anomalies discovered by these techniques with field mapping and drilling and the analysis of drill hole sampling.

The extraction of minerals from the ground is the domain of mining engineers. They take the models produced by geologists and determine where the mine should be located - because mineral deposits are not uniform and vary widely. They also determine which parts of the mineral deposit should be mined and how it is to be mined - open pit, underground, small or large scale stoping. They also determine the equipment to be used and with help from geotechnical/geomechanical engineers they determine the maximum size of openings that the ground can support during mining operations.

Once mineral bearing rocks (ore) have been mined, the minerals must be removed and concentrated. This is done by metallurgists in a processing plant. Depending on the minerals being processed, this can involved froth flotation (copper, zinc, lead, nickel), gravity techniques such as shaking tables (tin) or spirals, carbon in pulp processing (gold), magnetic separation (mineral sands), heavy media separation (iron ore). Most mineral processing methods require the use of water. Further refining is done by another group of metallurgists during smelting, if smelting is required.


Thunderstorms vs Thundershowers What is the difference when the weather report says thunderstorms vs when it says thundershowers and the picture is still the same?

Physically there is no difference. A thunderstorm is defined by occurrence of lightning, no matter how much lightning there is, if it's cloud-to-ground or intercloud.
Usually if meteorologists talk about thundershowers in weather reports they want to point out that there will be weaker thunderstorms (e.g. without hail, storm, heavy rainfall or the danger of flash floods).


Where to find an accurate Mercator Projection world image? I'm sorry if this doesn't fit "Earth Science" too well. No idea where else to ask this!

Can anyone help me find an accurate world map in Mercator Projection?
It doesn't need political borders or too much detail, just coastlines would do.
(Ideally with land coloured buff and sea coloured blue, but I'm not picky!)
I would be happy to pay, if it isn't too much - unless there are free resources out there!

I'm writing a modelling application where I need to plot Lat and Lon on a world chart so it needs to be fairly accurate (if you call Mercator Projection accurate).

Thanks for any help, and sorry if I've broken any rules here.

So here is the way I do that personnally with NaturalEarth data and R (but you can do something similar i m assuming with any programming language that can deal with GIS or any GIS software):

Fist download and unzip the file:

download.file("http://www.naturalearthdata.com/http//www.naturalearthdata.com/download/10m/physical/ne_10m_coastline.zip", "10m_coast.zip")
unzip("10m_coast.zip")

Then reads in the shapefile:

library(rgdal)
library(maptools)
a <- readShapeSpatial("ne_10m_coastline.shp",CRS("+proj=latlon +ellps=GRS80"))

Then project it:

a_merc <- spTransform(a,CRS("+proj=merc +ellps=GRS80"))

And plot it:

pdf(w=20,h=20,file="merc.pdf")
par(mar=c(0,0,0,0))
plot(a_merc,asp=1,xaxs="i",yaxs="i")
dev.off()

This is a very minimalist example of course, it only draws the coastlines (as a line by opposition to drawing the continents as polygons, that would allow a more advanced colouring scheme but the projection to mercator of polygons is more complex, as Antarctica creates problems).


Is there any place on Earth that is permanently a desert? I am interested to know if there is any place on Earth that is permanently a desert (except Antarctica). By permanent I do not mean to be the physical meaning of forever. It means the place has to be at least staying million of years as a desert and had survived at least one major climate change period. Precipitation is probably the most important factor to determine if a place would be a desert.

So, the question could be focused on a particular location which receive little precipitation despite how the overall global climate has changed (of course I still welcome discussion outside of the precipitation pattern).

UserLTK, above, has mentioned the Dry Valleys of Antarctica and the Atacama desert as two notable examples of "permanent" deserts. It's likely that these two locations have been deserts for at lease several millions of years despite changes in global weather patterns from multiple glacial events. The Atacama is well shielded by a very old mountain range to the west, and the Dry Valleys are also well protected by both an inland location and by global ocean currents that isolate the continent from much of the world's weather.


How is it possible that only the bottom half of the moon was showing? A few months ago I was in car and noticed moon. You could see bottom half (in crescent shape) but not top half.

How is this possible to look up into night sky and see only bottom half of moon?

It depends on the season and even more on latitude.

At any given time, the same side of the Moon faces the Sun.  Where you stand on Earth doesn't change which part of the Moon is lit, but if you think about the orientation of people on the earth, people in the Northern and Southern Hemisphere are "upside down" to each other and people on the equator are perpendicular.   The Moon doesn't change but the point of view of people on Earth relative to the Earth's surface makes a full 360 degrees of rotation based on latitude, so the same moon at the same time can appear as a left crescent, a right cresent, a boat and a yamaka depending on the person's latitude at the time of viewing.

Also explained here.

And this should probably be astronomy.


What are the ramifications to life on Earth when the Earth's magnetic poles switch? This question is related to this question about the cause of the Earth's magnetic field switching polarity.

My question is: How does this switch in the polarity of the magnetic field affect life on Earth?  Will it have detrimental effects to living organisms?

While this does not directly answer the question, these two ideas are relevant: Rare Earth hypothesis and Mediocrity principle.

More focused to the question, This letter to nature discusses the purposed link between evolution/mutation rate during of life and magnetic pole reversal periods. You see, when the magnetic fields reversed, it widely thought that it occurs over a period on the order of 1 - 10,000 years. During this reversal, the intensity of the magnetic field degrades to 0, and then increases from there in a reversed polarity. It is not a contentious position that during these field reversals the mutation rate (not sure about speciation rate) dramatically increases.


Has the Average Volume of Volcanic Emissions Been Constant Since the Last Major Fluctuation? Are total volcanic emissions worldwide constant, or do they rise and fall? We know there are large fluctuations on a scale of tens of millions of years, but is the total volume of emissions stable on a scale of tens of thousands, the last ten thousand in particular? The last major increase that I know of was shortly before the extinction of the dinosaurs and according to some geologists was the cause of the extinctions at the end of the Cretaceous, but I suspect there have been further significant episodes of volcanism since then.

If you have access, I would recommend you to read this short chapter of the Encyclopedia of Volcanoes. In summary:

At ocean ridges, studies show a steady rate of oceanic crust production during the Cenozoic. There have been fluctuations before, maybe due to the breakup of Pangea or other major tectonic events. The present volcanic production rate is ~20 km$^3$ per year.
At volcanic arcs, it is harder to constrain because of the poor preservation of volcanic material. Tephra layers found in deep sea drilling cores show some peaks in explosive activity "in the Quaternary (0-5 Ma), the middle Miocene (c. 13-17 Ma), and potentially the Eocene (c. 37-42 Ma)". This is not well explained. There is also a shorter term variability due to deglaciation episodes: mass unloading depressurize magmatic systems. A conservative estimate of the modern output is 0.5 km$^3$ per year.
Finally, Large Igneous Provinces (LIPs) are very episodic (long-term average of one LIP every 10-20 Ma) but they emit a large volume (generally > 1 million km$^3$) in a relatively short period of time (a few million years). LIP emplacement coincide with major mass extinction events.


How is the vertical velocity defined in sigma-pressure-coordinates? I have a problem in deriving/understanding the vertical velocity in sigma-pressure coordinates.

The vertical coordinate is defined as:

$$\sigma(x,y,p)=\frac{p(x,y)-p_t}{p_s(x,y)-p_t}$$

where $p(x,y)$ is the pressure of the considered grid point, $p_t$ is the pressure at the top of the domain (in my case $50$hPa) and $p_s(x,y)$ is the surface pressure.

After some derivation I get for the vertical velocity ($D/Dt$ is the total, $\partial/\partial t$ the partial derivative, $\omega = Dp/Dt$):

$$w = \frac{D \sigma}{Dt} = - \frac{\sigma}{(p_s-p_t)}  \left(\frac{\partial p_s}{\partial x} u + \frac{\partial p_s}{\partial y} v \right) + \frac{1}{p_s-p_t} \omega$$

When I now think of an idealized example where I have a gaussian hill in the middle of the domain and wind coming only from the south ($v=10$ms$^{-1}$, $u$, $\omega=0$), the resulting vertical wind component is positive in front of the hill which is wrong since the air should be ascending (positive value of $w$ means descending).

Where is my mistake?

There is a misconception in your assumption:
$\omega = \frac{Dp}{Dt} = 0 $ means that the mass above the air parcel stays constant.

Proof: Assume quasistatic eqn:
-$\frac{1}{g}\, dp=\rho \, dz$;
apply operator of horizontal mean: $\overline{(\cdot)}= \frac{\int (\cdot)  \, dxdy}{\int dxdy}=\frac{\int (\cdot)  \, dA}{\Delta A}$
-$\frac{1}{g}\, \overline{dp} \, \Delta A=\rho \, dxdydz= \rho dV = dM$
Integrating between arbitrary pressure levels gives mass between those levels.

(1) You correctly estimated $\partial p_s/\partial y <0 $ in order to have wind to the north, but
(2) you also set $\partial p_s/\partial t =0 $ in your derivation (to replace total derivative with advection of $p_s$). This means that the pressure field is constant in time.
Result
(1) and (2) yield to lower pressure in the north ($dp_s/dy<0$) and decreasing surface pressure following the parcel ($dp_s/dt<0$)
This means that an air parcel has to descend (in terms of $\sigma$) in order to satisfy the condition of constant mass lying over it ($\omega = \frac{Dp}{Dt} = 0 $):
$d\sigma/dt = a \, dp/dt- b\, dp_s/dt$; (with a,b const.)
=> $d\sigma/dt >0$
Example
If your parcel starts at 950 hPa, travels to north with falling surface pressure, condition $\omega=0$ means it stays at 950 hPa, but with (1) surface pressure drops to 950 hPa as the parcel continues north and the parcel miraculously is found to be at ground level.
Conclusion
As $\sigma$ depends on pressure and surface pressure, so does its time derivative.


Why is ignimbrite associated with felsic magmas? Why is ignimbrite associated with only more felsic magmas?

Felsic magmas contain much more silica (SiO2) than mafic magmas (almost by definition). The excess silica chains cause the magma to be much more viscous and therefore more prone to explosive eruptions (they trap gas and require high pressures to flow). This is why felsic magmas produce crazy explosive pyroclastic flows (forming ignimbrite) and very mafic magmas (like in Hawaii) just flow nicely downhill.

Btw, water decreases the viscosity of magmas, but the amount depends on composition as well as temperature. There is a nice transition between felsic magmas and mafic magmas showing that decrease in viscosity. Check out the source below:

Whittington et al (2009): "The viscosity of hydrous dacitic liquids: implications for the rheology of evolving silicic magmas"


Why does the colour of amethyst fade if exposed to too much light? It is well known that the purple hue that is characteristic of the amethyst quartz ($\ce{SiO2}$) will fade if the crystal is exposed to light for a prolonged period of time.  What is the underlying mechanism of this change?

The reason why amethyst loses its colour in sunlight is due in no small part to what impurity in the $\ce{SiO2}$ crystal structure gives the vivid purple and violet tones of amethyst.

According to several sources (1),(2),(3), the main source of the colour is naturally irradation-borne tetravalent iron $\ce{Fe^{4+}}$, which is formed via naturally occurring gamma radiation altering trivalent iron $\ce{Fe^{3+}}$ during crystalisation (3).  Other elements exist as impurities but are far less important considerations for the colour produced (3).

The tetravalent state of iron is inherently unstable in 'normal' surface conditions and the process is reversible due to prolonged exposure to natural sunlight (3).  Some research and experiments have demonstrated that some of the bleaching is caused by the UV portion of sunlight (4).

References

(1) Amethyst, Mindat.org

(2) Dudushenko et al. 2003, What Oxidation State of Iron Determines the Amethyst Colour?, ICAME 2003

(3) Hatipoğlu et al. 2011, Spectral, electron microscopic and chemical investigations of gamma-induced purple color zonings in amethyst crystals from the Dursunbey-Balıkesir region of Turkey, Radiation Effects and Defects in Solids: Incorporating Plasma Science and Plasma Technology

(4) Nunes et al. 2013, Spectroscopic study of natural quartz samples, Radiation Physics and Chemistry


Princples of process (systems) based modeling What books are available that address the fundamental principles all processed based modelers should be aware of?

Is there a guide, some holy grail of text books for process based simulation models?

Edit:
Process based, or system models such as those used to simulate ecological/biogeochemical/landscape processes.
As Naught101 mentioned: "process based modelling" refers to a computational-numerical mode built on a conceptual model that is mostly based on physical laws defined by empirical relationships. As opposed to a purely empirical/statistical model.

I guess the only thing the modeler should know is either the mathematical equation describing the system or the statistical relationship between a predictor and a predictand. You might have "access" to the exact equations or you might need to fit a mathematical model onto empirical observations. Then you need to code these mathematical or statistical relationship into a software (i.e. numerical model).

Fairly general. The devil will be in the details.


Why does NW coast of Scotland look like it does? (Similar to Norway, so different to other European coastlines) When looking at a map of Europe, I always wonder why the North-West coast of Scotland has a very similar craggy outline to the NW coast of Norway. It is completely different to the smooth outline of the Eastern coast:

So my question is:

What are the geological reasons for the distinctive outline of Scotland's North-West coast?

Hopefully a full explanation would include answers to the following questions:

Why are they the same in Norway? (were they once joined together?)
Why are they so different on the Eastern coast?

These are actually a geological feature called "fjord" which the Scandinavian Peninsula and surroundings (including Scotland) are known for. It is the result of glacial erosion during the Ice Ages. See more info here: Fjord (Wikipedia).


Is it possible to create ice in poles? Is it possible that human can built under the poles a controlled system to create again artificial icebergs? In order keep tight the melting ice and reduce the sea level? Can this system impact the quality of life and climate?

It depends on which pole.
The south pole is in the middle of Antarctica, with mean temperatures of -57°C, liquid water doesn't exist there and the air is extremely dry. Therefore, I would say that it is not possible to create more ice due to the lack of liquid water. And if there were any liquid water it would freeze naturally. This will make sense if we have a look at the antarctic geography. This map will help

[image from geology.com]

One possible action following your line of thought, would be to bring liquid water to the south pole from the coast and let it freeze there. However, the more than 500 km that separates the South pole to the nearest ocean shore (that is actually under hundreds of meters of ice) or 1,300 km to open water, makes this idea very impractical. A similar approach but more efficient would be to pump water from the coast to a nearby antarctic basin, and that would indeed help reducing sea level. This idea have been proposed by scientists. However, to make this effect significant you would need to pump incredible amounts of water, something that makes this geoengineering idea very costly and not very appealing.

Other scientist have proposed that dumping piles of rock in the ocean floor at specific points could be the most cost-effective way to slowdown sea level rise. The idea is to redirect warm ocean currents away from glaciers, something that could significantly reduce the rate at which they are melting down. This approach would have a much lower (but still very high) cost.

This paper explain this idea and the following figure summarizes it:

The North pole in contrast is just in the middle of the Arctic ocean. You could indeed take ocean water there and turn it into icebergs. However, as others have said in the comments, using any kind of cooling system would produce a lot of heat so it would not be a good idea. But you can just enhance the heat transfer with the atmosphere as ski resorts do to make artificial snow. Their approach is to wait for a cold day and spray water into the air. If it is cold enough, the water droplets will turn into ice before falling back to the ground.

However, even if you succeed in making icebergs, that would not make any change in sea level, because they are floating. It would be equivalent of melting of ice cubes in a glass, something that doesn't change the level of the liquid in the glass. Here a graphical example of that

Nevertheless, your feat of engineering would have a positive effect in slowing global warming by covering the ocean with a layer of highly reflective ice. That ice would reflect back to space a lot of sunlight that would have been absorbed by the ocean otherwise. However, when you freeze sea water, most of the salt is expelled, so you would also put a lot of salt into the water, that would make sea water more dense and it would sink. That could have a undesired effect on ocean circulation, so you have to be very careful in studying the side effects of such approach.

Similar to the antarctic approach. You might get better results if you pump water from the Arctic ocean and let it freeze on top of a desolate arctic island. However, it still doesn't seem to be the most cost effective approach.

Said that, there is a long list of geoengineering ideas to battle against climate change and sea level rise. However, the most cost-effective way to slowdown sea level rise, is to reduce the rate at which we are consuming stuff. So just buy less and reduce/repair more. Also very important is reducing the use of fossil fuels (something that would also be a side effect of consuming less). Having less children or adopting instead of having your own is also a way to make big contributions to slow down sea level rise.


Are we changing Earth's weather with global warming? I think that when the air heats up in the day, the radiation from the ground contributes way more to its heating at altitudes more than 300 meters above the ground than convection currents of air heat from the ground.

I also think radiative cooling of the air directly contributes way more to the cooling of air more than 300 meters above the ground than conduction from the ground. I don't see how the air at that height could be so fast to warm up and cool just by conduction from the ground.

If these assumptions are true, does the carbon dioxide we released into the air speed up the absorption of radiation from the ground by the air in the day and the radiative cooling of the air at night because Carbon dioxide absorbs infrared light better than air?

First, regarding your assumptions, here is a graphic from this online textbook.

As you can see, your first assumption is correct, surface radiation is much more significant than thermals. Your second assumption is also correct, 'Back Radiation' and 'Emitted by Atmosphere' flows are significant, but absorption of heat by the ground from the air isn't even featured on this chart. So conductive heat transfer from air to ground is negligible.

This page gives some good background on how carbon dioxide contributes to global warming, and, as you said, it is due to absorption of infra-red radiation from both the ground and the air. Specifically, CO$_2$ absorbs IR wavelengths that can 'escape' absorption in water vapor (the primary greenhouse gas) in the range 12-15 $\mu$m, as shown in the graphic below.

With more thermal radiation absorbed in the air, less escapes into space, and the net energy balance of Earth is positive which results in a slow and steady warming.


What would people drilling through Mount Everest find? I am interested in knowing what kind of fossils we would find if we were to drill horizontally through the mountain and what we would find if we were to drill vertically. Would we find anything interesting other than the fossils?

The summit of the mountain is made up of 400 million year old sedimentary rocks laid down long before the uplift 50 million years ago.  These rocks contain marine fossils including Trilobites and Crinoids. If you drilled down from the summit you would then encounter older metamorphic rocks,  the upper parts of which contain traces of fossils, and then in to gneisses and granites.
http://all-geo.org/metageologist/2012/06/the-geology-of-mount-everest/


How can every ton of CO2 cost 3 square meters of summer sea ice per year - quantitatively? The Science article The average U.S. family destroys a football field's worth of Arctic sea ice every 30 years states:

  Every additional metric ton of carbon dioxide (CO2) puffed into the atmosphere appears to cost the Arctic another 3 square meters of summer sea ice.

which carries a link to the abstract of a peer-reviewed Science paper Observed Arctic sea-ice loss directly follows anthropogenic CO2 emission. However the abstract says (in part):

  Since climate-model simulations of the sea-ice loss differ substantially, we here use a robust linear relationship between monthly-mean September sea-ice area and cumulative CO2 emissions to infer the future evolution of Arctic summer sea ice directly from the observational record. The observed linear relationship implies a sustained loss of 3 ± 0.3 m2 of September sea-ice area per metric ton of CO2 emission.

My question is about the simplification of linking tons of CO2 to square meters of ice, and without reference to time. The abstract seems to simply say that there appears to be a linear relationship, and since models disagree, then this is a "good enough" way to think about it.

Is it so simple - if in 2017 no CO2 were burned the sea ice would return to normal? No. The summer sea ice would likely continue to decrease for decades. An analogy might be births and deaths of a population. While there might be a rough (or "robust") correlation between birth rate and death rate, a cessation of births in a given year would have almost no impact on death rate for perhaps a half-century.

Is there any mathematics that justifies this simple "robust linear relationship" to be causal? What does "directly follows" mean?

I'm not in any way questioning the causality between CO2 and a wide variety of changes in climate, including reduction in summer sea-ice. I'm only questioning the original quote and the quantitative relationship: 1 metric ton of CO2 costs 3 square meters of summer sea ice.

above x2: Graphics from Science Magazine.

First lets take the question at face value and do the simple comparison. I will take the years 1979 and 2016 as arbitrary example, over a 37 year period - the longest for which accurate data are available. During that time the minimum extent of Arctic sea ice, defined as the area of Ocean with at least 15% of sea ice (as determined by satellite) decreased from 6.93 to 4.14 million square kilometers. That is, a decrease of 2.79 M Km2. The actual ice loss was much greater because of ice thinning, but that is incidental to the question. During the same period the CO2 emissions by the USA increased by about 160 M tonnes. So on the face of it, assuming a direct linear relationship, 1 tonne of emitted carbon from America results in an average of 0.029 km2 reduction in ice, or about 3 hectares (Not Km2! let's get the units correct!).

Of course, as every scientist knows, a correlation - even a good correlation, doesn't necessarily imply causation. In this case it would be correct to say that every tonne of burned coal eventually contributes towards the loss of Arctic ice, but the whole process is much more complex, with an abundance of other contributing factors, feedback processes, and non-linear relationships coming into play. Among these complicating factors are Arctic ice thinning, changing Arctic albedo, changing ocean-scale oscillations, Other country emissions, inter-annual changes in thermal inertia (land, ice, sea and atmosphere), and high-level atmospheric chemistry (volcanic gasses, aerosols, etc.). So although there is an element of truth in your article, it would be naive to imply a direct relationship.

To keep an eye on how the Arctic ice is responding to climate change I highly recommend
http://nsidc.org/arcticseaicenews/


Are oceans a major factor in creating high winds on a planet? This question only pertains to oceans of water and how much they account for the process of creating high winds on a planet with any type of atmosphere.

The major factor is not the size or temperature of the ocean, it is the differential temperatures, and hence large scale convection, such as Hadley cells, Monsoons and tropical storms. With the latter, large oceans are relatively deep with thin warm water over vastly deeper cold water. The minimum temperature for as hurricane to form is about $27^\circ\!$C ($80^\circ\!$F), which most commonly develops over relatively shallow water, or where there is a massive influx of warm water such as the current El Niño.


Is there a high-temperature, non-magnetic glue that doesn't dissolve in water? I have very small mineral samples, and I'm looking for a glue that can hold them through a sample preparation process that I'm doing: heating, polishing, and measuring magnetic moment. For that I want the glue to have 3 criteria:

heat resistant (over 600 Celsius)
can hold through polishing (therefore can't dissolve in water)
very important: that it won't acquire magnetic moment after being in an external field, since I want to measure very weak magnetic moment from my samples.

I tried AREMCO Ceramabond 569. My measurements showed that it does acquire a  magnetic moment when exposed to an external magnetic field (it was recommended by the company).

Your question is quite similar to one that I asked some time ago, with the additional requirement that the glue be insoluble in water, which unfortunately excludes sodium and potassium silicate. Like you, I've found Ceramabond (albeit 571, not 569, in my case) to be too magnetic. I suspect that there's an element of random variation here. It's not (as far as I know) specifically formulated to be completely non-magnetic, so there may be some batches which are more magnetic than others. Khakhalova and Feinberg (2014) investigated some other high-temperature ceramic adhesives and found that they were also too magnetic for use with weakly magnetic samples. However, they do make one useful suggestion:

  It may be possible for rock and paleomagnetic labs to reduce the concentration of magnetic contamination in Omega cements, for
  example, by sending the powder through a very clean Franz magnetic separator
  multiple times.

I haven't yet heard of anyone actually doing this, but it certainly seems worth trying. They also write that

  We’ve contacted Omega Engineering Inc. regarding the iron concentrations in their
  cements and their technical staff are
  currently exploring whether it would be
  possible to produce a high purity, high
  temperature cement specifically for rock
  magnetic and paleomagnetic applications.

I don't know if anything has come of those attempts in the three years since the article was published, but you could email the authors and/or Omega to find out.

References

Khakhalova, Evgeniya and Feinberg, Josh M. (2014).
The iron that binds: The unexpectedly strong magnetism of high-temperature ceramic cements commonly used in rock magnetic experiments. IRM Quarterly, 24(2), url: http://www.irm.umn.edu/quarterly/irmq24-2.pdf


Can large earthquakes happen twice/thrice at the same place within a short timeframe I want to know if large earthquakes can happen twice in the same region?
The reason is that the recent earthquake in Nepal was followed by many after shocks of considerable magnitude.

I wanted to know if there are chances of earthquake of this magnitude in the same region again.
Can we expect another earthquake in the same region, lets say in a month or few months?

Aftershocks after a major earthquake can occur for a period of weeks after the initial major earthquake, but the magnitude of the aftershocks is always less than that of the initial major quake. The paper History of Earthquakes of India & the Himalayas discusses the each of the major earthquakes in the region for the last 200 years. Information on earthquakes before 1800 is patchy. The earthquakes discussed are the ones that occurred in: 1803, 1833, 1869, 1897 & 1905.

Nothing was mentioned about a second or third major earthquake happening shortly after a major earthquake; even for the devastating 1934 earthquake.

Due to the different tectonic settings and causes for earthquakes in different parts of the world it is best not to look at the history of one part of the world and assume the same will occur elsewhere. The expectancy of earthquakes and their patterns in the Himalayas should not be compared with earthquakes in Japan, New Zealand, western USA, Turkey or elsewhere.


What negative side effects would occur if silicate mining were used to artificially lower atmospheric CO2 concentrations? As one half of the naturally occurring Carbonate–silicate cycle, carbon dioxide is naturally removed from the atmosphere by the chemical reaction:

CaSiO$_3$ + 2CO$_2$ + H$_2$O → Ca2+(aq) + 2HCO$_3$-(aq) + SiO$_2$

What would be the side effects of artificially enhancing this process by mining large amounts (on the order of 10 times world coal production) of silicate bearing rocks to reverse man-made climate change?

A review article on the subject in the AGU journal Reviews of Geophysics Enhanced chemical weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification by Hartmann, et.al. (2013) notes many uncertainties that would need to be researched and quantified to evaluate both the potential effectiveness as well as the drawbacks of the process, known as Enhanced Weathering:

  "The potential negative environmental impact of Enhanced Weathering is
  also important to consider and investigate further. Application of
  rock powder to the land surface might increase the concentration of
  airborne dust in the local environment. The potential risk to human
  and animal health may limit the appropriate application sites (away
  from human centres or sensitive ecosystems) or the severity of
  comminution, depending on the techniques applied. This in turn will
  limit the efficacy and effectiveness of Enhanced Weathering. The
  mobilization of potentially toxic elements contained in some silicate
  rocks may detrimentally effect primary production and/or accumulate in
  the food chain, both of which could be harmful to human populations.
  Therefore an assessment of usable rocks and their locations is
  needed."

Also:

  To sequester a significant amount of carbon dioxide from the
  atmosphere, an Enhanced Weathering program would need to process 1Gt
  to 10 s of Gt of rock per year. This would make it one of the largest
  global industries.

That alone would create economic and social impacts, as well as additional carbon emissions that would need to be offset.


Why is carbon pollution given more importance than Sulfur pollution or Nitrogen pollution? Nitrous oxide ($N_2O$) - primary greenhouse gas
Carbon dioxide ($CO_2$) - primary greenhouse gas
Methane ($CH_4$) - primary greenhouse gas, explosive
Nitrogen monoxide ($NO$) - secondary greenhouse gas, toxic
Nitrogen dioxide ($NO_2$) - secondary greenhouse gas, toxic
Sulfur dioxide ($SO_2$) - secondary greenhouse gas, toxic
Carbon monoxide ($CO$) - secondary greenhouse gas, toxic

So, why is Carbon Dioxide pollution  given more importance in "pollution measurement"(Carbon-Footprints), when Sulfur Dioxide and Nitrogen Dioxide are much more dangerous to Land dwellers, including Humans ?

At this rate, the Oceans will die from Nitrogen pollution or acidify from Plastic pollution; before the ocean level can even threaten us. So, why are we focusing on Carbon dioxide at the cost of the toxic compounds ?

greenhouse gases other than CO2

The gases N2O and CH4 are relevant greenhouse gases besides CO2. They even have a stronger warming impact per molecule. A brief summary for N2O is provided in its Wikipedia article.

Edited later on (thanks to Communisty for the comment): The global warming impact of these greenhouse gases other than CO2 is measured/presented in CO2-equivalents: i.e. the warming potential of N2O equals 298 CO2-equivalents, which means that one N2O molecule is 298 times worse than a CO2 with respect to its warming potential. Therefore, CO2 is more visible in the media.

Why focus more on CO2?

contribution to global warming

Although N2O and CH4 have a stronger greenhouse impact than CO2 per molecule, the concentrations of them are considerably lower. Therefore, in sum (heat trapping potential x number) CO2 has a stronger impact on climate change. The figure below visualizes it nicely (please find the reference below):

Figure TS.6 on page 53 of the 5th IPCC Assessment on the Physical Science Basis (www.ipcc.ch/report/ar5/wg1/).

practical aspects

There are also practical aspects why a focus is put on CO2: many CO2 emission sources are know and clearly to identify (combustion processes). Moreover, many of the CO2 sources are point sources. Some of them are many and small (cars) but nonetheless: we know them and know to locate them.

In contrast, N2O and CH4 emissions sources are often diffusive sources (or area sources) such as natural and agricultural soils and cattle (and other) life stock. Here you find a text and a nice figure on this topic: www.soest.hawaii.edu/mguidry/Unnamed_Site_2/Chapter%202/Chapter2C3.html

Thus, it is easier to reduce CO2 emission by specific measures: don't combust so much fuel/combustion-material.

greenhouse gases vs. air pollution

As stated above, CO2 (in sum) has a higher global warming impact (in the moment). And large parts of its emissions are easier to manage. Therefore, the focus is on CO2.

Moreover, greenhouse gas emissions have a global impact: the greenhouse gases alter the global climate. In contrast, air pollutants have a local or regional impact. Also their life time or/and residence time in the lower troposphere is shorter than the residence time of greenhouse gases in the atmosphere. Therefore, the temporal and spatial extend of greenhouse gases is larger/longer than that of air pollutants. Thus, one focuses more on the longer lasting global problem: greenhouse gases.

regional vs. global

Because greenhouse gas emissions cause global problems they are tackled on a global level -- IPCC, United Nations Climate Change Conferences, etc.

Although air pollution is also a topic dealt with on global or continental level (e.g. hemispheric transport of air pollutants (HTAP), European Monitoring and Evaluation Programme (EMEP)), it is mainly a regional or local problem.

In Europe many municipalities have recognized the problem of air pollution in cities and try to deal with it (actually, they are forced by the EU). Also in Chinese cities municipalities start working on this topic.


Converting Wind Movement to Wind Speed I'm looking through historical weather station information from NOAA, and I notice some stations do not have wind speed information but do track Wind Movement(WDMV) over a 24 hour period in kilometers. Would a rough conversion of this to wind speed be: Wind Movement/24 = Wind Speed(km/hr), this seems like too basic of a conversion and I realize is not a true average hourly wind speed.

IF there has been a steady wind direction over that 24 hrs, then yes, this will give you the average wind speed.

If the wind has changed direction, then there may have been higher speeds that have partially cancelled each other out.


What kind of minerals have no cleavage plane? Why does quartz have no cleavage plane and halite does? What do I need to know about the specific mineral so that I can decide whether it has cleavage or not? I need some kind of rule.

I'm pretty sure a more rigorous answer deserves to come along, but I can give a simple overview of some of the important factors.

Cleavage planes have to do with bond strength and bond geometry.  If there isn't a plane of bonds that can be cut through, then you won't get cleavage.  When a mineral is fractured, the fracture "wants" to take the path where the total energy required to break all of the bonds along that path is at a minimum.

In Halite, you can "cleave" a perfect plane through weaker ionic bonds (the geometry works, and the bonds are weak).  In quartz, all of the bonds are of the same strength (strong silicate bonds), and the geometry of the mineral is such that you can not find a plane that will cut through all of the bonds, therefore the fractures must "wander" creating the conchoidal structures.  In mica, the cleavage planes form between the silicate sheets.  The silica bonds are strong, the the sheets are held together by weaker ionic bonds.


How do subsurface oceans form under a rocky crust? New data about Ceres has just been released. Raymond et al. (2020) show the existence of gravity anomalies interpreted as low density pockets of brine under the crust. They show how impacts can trigger eruption of this brine onto the surface.
I understand how a low density layer can remain trapped under a higher density layer by lack of pores and/or fractures to rise through by buoyancy. However, I cannot figure how it got trapped there in the first place? For subsurface oceans under an icy crust (like Europa), I can imagine a simple freezing mechanism, but Ceres has a rocky crust.
Wikipedia's Ocean World - Formation goes:

Since water is highly soluble in magma, a large fraction of the
planet's water content will initially be trapped in the mantle. As the
planet cools and the mantle begins to solidify from the bottom up,
large amounts of water (between 60% and 99% of the total amount in the
mantle) are exsolved to form a steam atmosphere, which may eventually
condense to form an ocean.

But it doesn't really help as it applies to surface oceans only. Neither does Extraterrestrial oceans on that particular matter.
How do subsurface oceans form under a rocky crust?

As Jean-Marie Prival comments, Ceres doesn't have a rocky crust.  It has an icy crust in which rocky matter is embedded from asteroid impacts.  I'd rather see this comment turned into an answer than reinvent the wheel on that dwarf planet.  In case they "die", the relevant comments are quoted below the main body of the answer..
Instead, here I consider a celestial body closer at hand.  Earth does not have a subterranean ocean but it can produce water deep in the mantle, extracted from rock.  As described in this answer from Space Exploration Stack Exchange, a high-pressure solid phase of water, Ice VII, has been identified as inclusions in diamonds; the presence of these inclusions implies that water exists in the molecular state ($\text{H}_2\text{O}$) as distinct from hydroxyl groups in minerals.  The water is first trapped as a supercritical fluid as the diamonds form deep in the mantle, then condenses to Ice VII as the diamonds cool at the surface but retain mantle-level pressures internally.
Water in Earth's mantle likely does not come directly from surface oceans, but from hydroxide-bearing minerals in the rock.  When the rock is cycled downwards by plate tectonics, it becomes hot enough to decompose the hydroxides (hydroxides of silicon, aluminum, iron, calcium, and magnesium, the elements to which hydroxyl groups are most likely to be bound in crustal rocks, all decompose well below 1000°C), thus generating the subterranean water.

Previous comments
There seems to be a whole bunch of publications on the matter: nature.com/articles/s41550-020-1146-8, nature.com/articles/s41550-020-1019-1, nature.com/articles/s41561-020-0581-6. I don't have access to all of them (too expensive ...). Maybe there's some useful information on the matter. – user20217 Aug 12 at 12:59
Interesting! The first one states that "the interior of Ceres consists of (1) a thin lag deposit (regolith) layer, (2) an icy crust that contains the bulk of an origin ocean [...]". That would explain a lot, the rocky layer being created on top of the icy surface by impacts. What got me was this passage in doi.org/10.1038/s41467-020-15973-8 : "Ceres [...] is partially differentiated into a rocky interior and a comparatively more volatile-rich crust, which is composed of rock, salts, clathrates, and ≤ 40% water ice." Looks like the crust might not be so "rocky" after all... – Jean-Marie Prival Aug 12 at 14:10


Does the amount of energy released from burning of fossil fuels have a measurable impact on global warming? I understand that the main issue of global warming is greenhouse gases that trap solar energy instead of allowing it to bounce back into space. That being said, I've always had this impression or idea that the amount of energy released from burning fossil fuels should also have an effect. Consider from antiquity to about 1600 AD, the sum of heat being dumped into the atmosphere came from the sun. Now, after the industrial revolution, a new source has been added, that being human activity (burning coal, burning petrol, burning natural gas, thermonuclear weapons, nuclear reactors). While I suspect human activity has no measurable comparison against the output of the sun, I'm wondering if it has an impact on global warming to any degree.

Yes, it does add to global warming.

No, it's not currently measurable.

Human primary non-renewable energy consumption is about 15TW - and pretty much all of that goes into low-grade heat in the ocean surface and the atmosphere.

Expressed in the same terms as the forcing units of global warming, the forcing effect of that heat is about 1.7% of the effect of the anthropogenic release of $\ce{CO2}$ to date.

So we can calculate it, but it's not directly measurable as a change to global energy content: it matters, but it's not quantifiable from temperature observations, given current data and techniques.

(Kudos to Pont for the link to the paper)


Sea Level in Paleogeographic Maps Most paleogeographic maps available (C. R. Scotese or R. Blakey maps for instance) show not only the shape of the continents during the concerned period but also the level of the seas and oceans (i. e. the coastlines, the epicontinental seas, etc.).

Since Haq et al. 1987, there has been quite a few reconstructions of the global relative sea level changes for parts of the Phanerozoic. But going from such global curves to actual maps showing the approximative coastlines and epicontinental seas does require a fair amount of extra information such as paleobathymetry of the oceans and paleoaltimetry of the continents to name the more obvious.

So my question is: do we have such informations on a global scale? Or are the sea level representation on such maps just a shot in the dark?

There are various plate tectonic models around, that are able to provide insight in paleobathymetry and -altimetry. These models include information on sea floor spreading and subduction, which provides much information on bathymetry. Also plate tectonic movement largely drives the uplift of mountain ranges, and combining this with isostatic effects of sediment loading, glaciation, etc. you can get a fair picture of paleoaltimetry as well. Of course this method provides only relatively low resolution data, and to get more detailed maps you need more localised data.

Outcrops and bore holes provide much information on the depositional environment, and for example sequence stratigraphy is a tool that can be used to predict/retrodict regional environments. If you know from a number of locations where the coastline was relative to its current position, and know from models etc. where the sampling locations were in the past you can map paleocoastlines as well.

So to answer your question shortly, yes there is a lot of global information available by combining large scale models and local investigations, and where such information is missing you can at least provide an educated guess of coastal positions.


Ore Reserve Definition I've seen many papers on mineral deposits say something along the line of "a 100,000 tonne deposit of Zn, 1% grade." Does this mean there is 1% of 100,000 tonnes which is 1000 tonnes pure zinc, or does it mean there is a total zinc deposit of 100,000 which is 1% of the total giving 10,000,000 tonnes including the waste material?

Ore reserves represent the economic portion of a mineral deposit. They are reported as tonnes and grade above a minimum value (cut-off grade).

Irrespective of whether the ore reserve will be mined by surface or underground methods the deposit is blocked out and the mass of each block and the mass of the valuable commodity (zinc, copper, gold, etc.) is calculated for each block. From this the grade of each block is also determined. The reserve is determined by summing the masses of all the blocks and determining the overall grade of the total.

In your example, a deposit of 100,000 tonnes grading 1% zinc means there is 100,000 tonnes of rock that can be mining and treated by a processing plant (mill). The amount of zinc metal contained within that 100,000 tonnes of rock is 1000 tonnes.

Similarly, a gold deposit that contains 2 Mt @ 8 g/t, contains 2 million tonnes of rock grading 8 grams per tonne, or 8 parts per million. The amount of gold contained in that 2 million tonnes is 16,000,000 g (16,000 kg or 16 t).


What are the differences between geology, petrology, and lithology? What differences are there between  geology, petrology, and lithology?

If I were to get into any of those fields, what exactly would I be studying?

Also, are petrology and lithology just branches of geology?

The basic differences are:

Geology

study of rocks and minerals: the study of the structure of the Earth or another planet, especially its rocks, soil, and minerals, and its history and origins
structure of area: the rocks, minerals, and physical structure of a specific area

Petrology

study of rocks: the study of sedimentary, igneous, and metamorphic rocks with respect to their occurrence, structure, origin, history, and mineral content

Lithology

description of the physical characteristics of a rock unit or rock formation, and actually not a scientific discipline as the two above


What would be the correct terminology for soft cover on crust? Earths' crust is usually not exposed. Above-water portion is covered with soil, and Underwater portions are covered with various deposits or sediments. Oceans contain Pelagic sediments.(I don't know whether this underwater sediment considered as soil or not).

The soft cover is probably not being considered as Crust. Some sources telling it
pedosphere (soil-sphere), but with pictures of only terrestrial soil.

But it is not clear to me :  exact how-much portion is being called pedosphere? Is it the whole skin of Earth (including underwater-depositions)? If not; then

what is the correct term for the complete soft-layer on Earth?
Is there any term for part-of skin-of-Earth which is beneath water?

what is the correct term for the complete soft-layer on Earth?

Sediments.

  Is there any term for part-of skin-of-Earth which is beneath water?

Marine sediments.

  The soft cover is probably not being considered as Crust

It is definitely part of the crust. When discussing mantle-crust issues, then crust is usually in the context of crystalline rocks, but it depends on context.

  But it is not clear to me : exact how-much portion is being called pedosphere? Is it the whole skin of Earth (including underwater-depositions)?

Pedosphere refers to terrestrial soil and sediments, and it usually discussed in context with other "spheres" such as atmosphere and lithosphere. Sediments (and marine sediments) is a neutral term.

As always, in Earth Sciences, there are several terms for the same thing. There is no "correct" term, just "better" when discussing said thing in various circles.


Does general relativity influence climate (vs Newtonian mechanics) That may sounds like a silly question but here it is.

One of the early great successes of general relativity was to explain the discrepancy between the prehilion advance of Mercury predicted by Newtonian mechanics and the results of its actual measurement.

I was wondering if this kind of effect could have any influence on the climate of a planet experiencing it.

In short: No. Unless multi-million timescales are considered.

The reason we keep teaching Newtonian mechanics, is because it is a VERY accurate approximation of a more general theory (general relativity) within the regimes of speed and gravity acceleration found in everyday life. Therefore, all the relativistic corrections to Newtonian mechanics in the Earth system are negligible. Both, for the internal operations of the climate and for the evolution of its orbital parameters on timescales of hundreds of millennia or shorter.

One effect, would be the minor role that apsidal precession have on the change of distribution of incoming solar energy described by the Milankovic cycles. But that can arguably considered negligible.

But perhaps the most important contribution would be the influence of relativistic corrections in Earth's orbit eccentricity variations on multi-million years timescales.

State-of-the-art orbital solutions for the long-term motion of the Earth like La2010, do use relativistic correction, however they are rather small. The way the corrections are included in the model are described by Saha & Tremaine (1994), where they point that:

  General relativistic effects in planetary motion have fractional
  amplitude of order $\frac{k^2}{c^2 r} \sim 10^{-8}$ at $r = 1 \,  \textbf{AU}$.

Meaning that the correction correspond to a 0.000001% of the total variation of the orbital parameters. Unquestionably, even such small corrections have a cumulative effect over multi-million years timescales. Varadi et. at. (2003), compares the output of a model using relativistic corrections (solid line) with one not using them (dashed line), and the following figure show the results over 3 million years, where can be observed that significant differences arise after 300,000 years.

However, it is reasonable to consider that such small corrections would have been overcome at some point in the past by some other unaccounted effects, like large meteorite impacts (or fly-by), solar storms, etc. Remember that La2010 go back 50 million years and other models go back several billion years, when such events were rather common. So, I would still argue that relativistic corrections are not very significant. However, in a chaotic system like Earth's climate, you can never rule out that a negligible forcing could have had an important effect.

Of course the answer would be different (and the relative importance higher) if we consider a planet orbiting extremely close to a super-massive star. But, I'm assuming you are mostly considering planets similar to Earth in that regard.

There are also some claims (the Damhsa Theory) that gravitational waves might have play a role in the very long term climate evolution of Earth. However, I'm not capable to really assess the validity of such theory, but I have to admit I'm skeptical about it. I've posted a question about that in Physics SE, an there seem to be wide consensus that such effect would be exceedingly small to ever deserve any kind of consideration.