Question:
What Magnitude does it Feel Like when Far Away in an Earthquake?
I can't find a good way to say this but, if I had some info about an earthquake (i.e. magnitude 8, originating in water) and if I had a distance (i.e. 850 miles/ 1370 km) could I calculate what it would be if that specific location was the epicenter? So, maybe it would be like a 3 or 4 maybe?I'm looking for a formula or calculator. If it is not possible, please tell me! It is fine if it is rough.

Explanation: The Richter and other magnitude scales measure the energy released by an earthquake, while intensity scales like the Mercalli scale measure the shaking or damage experienced at a specific location, which depends on factors such as distance from the earthquake and local soil conditions.

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The question doesn't really make sense.

The Richter and other [ seismic magnitude scales
](https://en.wikipedia.org/wiki/Seismic_magnitude_scales) are measures of how
much energy was released by an earthquake or how much work it did. An
earthquake doesn't "feel like" any particular magnitude at any given point;
rather, magnitude is an inherent attribute of the earthquake itself.

"Feels like" is measured on [ seismic intensity scales
](https://en.wikipedia.org/wiki/Seismic_intensity_scales) such as the Mercalli
scale. These measure the peak acceleration or velocity at a given point, or
the damage done by the earthquake. Intensity is influenced by many things,
such as the depth of the earthquake, the distance to the ruptured section of
the fault, and the local surface material.

Translating between the two is difficult, and requires knowing the detailed
geology of the area involved. The picture below is a USGS map of two
earthquakes of comparable magnitude, the [ 1994 Northridge earthquake
](https://en.wikipedia.org/wiki/1994_Northridge_earthquake) and an 1895
earthquake on the [ New Madrid Seismic Zone
](https://en.wikipedia.org/wiki/New_Madrid_Seismic_Zone#1812%E2%80%931900) .
In both cases, the outer zone is an intensity of Mercalli II or above, while
the inner zone is an intensity of Mercalli VI or above.

[ ![A map of the United States, showing the effects of two earthquakes.  The
1994 Northridge earthquake affected an area consisting mostly of southern
California, with a small damage area.  The 1895 New Madrid earthquake affected
most of the eastern United States, with a damage area covering large parts of
Tennessee, Kentucky, Ohio, Indiana, Illinois, and
Missouri.](https://i.sstatic.net/yP3vh.jpg) ](https://i.sstatic.net/yP3vh.jpg)


Question:
For some time now, I've noticed that mountains in southeast Asia seem to be unusually "jagged" with steep surfaces. My basic knowledge of how mountains are formed (via geologic processes) tells me that it's more common to find mountains like these in glacial areas (e.g. northern Canada, Norway, etc.), whereas those formed by tectonic plate collisions appear more "traditional" (e.g. main range of Himalayas, Andes, etc.), and geologically old mountains have a weathered appearance (e.g. Appalachians).

What caused/causes these SE Asian mountains to have their distinct appearance?

Explanation: The "jagged mountains" in SE Asia is just Karst landform

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David Hammen has already answered with the correct term in his comment.

* * *

Karsts are formed as water dissolve rocks, typically [ carbonates
](https://en.wikipedia.org/wiki/Carbonate_rock) (as limestone or dolomite) or
[ evaporites ](https://en.wikipedia.org/wiki/Evaporite) .

Karst landscapes can originate from karst caves, formed by groundwater flowing
through the rocks. When the caves eventually collapse ( [ see image here
](http://1.bp.blogspot.com/_JRp7TJWTx4A/S8Zvpncq70I/AAAAAAAAAVU/HPmQaOgb0d8/s1600/KarstDiagram-70pct-730206.jpg)
) a rugged landscape is left behind. Karsts are also formed on the surface as
limestone dissolves and forms spectacular landscapes, as the [ Tsingy
](https://en.wikipedia.org/wiki/Tsingy_de_Bemaraha_Strict_Nature_Reserve) in
Madagascar or from sea erosion, e.g. [ calanques
](https://en.wikipedia.org/wiki/Calanque) (karstic valleys).

[ ![\(My own picture.\)](https://i.sstatic.net/t22se.jpg)
](https://i.sstatic.net/t22se.jpg)

The landscape is also known as [ Pepino Hills
](https://www.britannica.com/science/pepino-hill) sometimes [ mogotes
](https://en.wikipedia.org/wiki/Mogote) , if they are surrounded by flat
landscape.

Another interesting feature is that as karst caves collapse, the cavity fills
up with material from the ceiling and the cavity can continue to migrate
upwards through the stratigraphy. Those karsts can be important channels for
groundwater or petroleum. Sometimes the collapse material is more resistant to
erosion than the surrounding rocks, and we get pinnacles of karst breccia left
behind.


Question:
According to this article from 2015 How much oil is left on Earth

1.5 trillion barrels of crude oil reserves were left in the world by end 2015

But how much oil was already consumed worldwide since it was started to use massively in the mid 19th century? Is it most of it or a small part of it?

PS: I'm not sure if this question is for Earth Science SE or for Economy SE, if you think it's in the wrong SE please move it.

Explanation: The articles critique the U.S. Energy Information Administration (EIA) for making overly optimistic forecasts about future oil production levels. The EIA's past forecasts for regions like the North Sea, Mexico, Alaska, and the Gulf of Mexico significantly overestimated actual production levels. For shale/tight oil plays like the Bakken and Eagle Ford, high decline rates necessitate constant new drilling just to maintain output, suggesting tight oil production is a short-term phenomenon. Overall, the articles argue the EIA portrays economically recoverable oil resources as much larger than they likely are, with depletion of finite oil supplies happening more rapidly than the EIA's rosy forecasts indicate.

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[ Cumulative world oil production at the end of 2017 was approximately 1.36
trillion barrels ](https://www.resilience.org/stories/2018-03-12/the-world-
oil-supply-is-infinite-i-know-that-because-i-believe-it/) .


Question:
I have a theoretical exercise where I calculated the amount of CO2 that is released to the atmosphere per year (4.6 ppm). We assume that the relative increase of CO2 is 2 ppm, hence the percentage of CO2 that stays in the atmosphere is around 2/4.6 ~ 40 %.

What is the technical term for this percentage?

Explanation: The persontage of co2 in atmosphere is a phenomenon called airborne fraction

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We call this the [ airborne fraction
](https://en.wikipedia.org/wiki/Airborne_fraction) , although as the name
suggests, it's normally expressed as a fraction rather than a percentage.

[ Raupach et al (2014) ](https://www.biogeosciences.net/11/3453/2014/) is an
(open access) example of it being used in the literature, and in that paper
they quote a long-term 1959 to 2012 value of 0.44, so in the same ball-park as
your estimate. Similarly, here's an example of it's use in [ Chapter 7 of the
IPCC AR4 ](https://ipcc.ch/publications_and_data/ar4/wg1/en/ch7s7-3-5-2.html)
with a range of modelled values from 0.4 to 0.5. It's also often calculated
over single years, as in your example, to look at the trends and variability.

As an aside, the 2 ppm in your calculation is called the [ atmospheric CO2
growth rate ](https://www.newscientist.com/article/2112153-a-pause-in-growth-
rate-of-atmospheric-co2-is-over-heres-why/) and the total mass of CO2 in the
atmosphere would be the atmospheric CO2 _burden_ .


Question:
Reviewing market regulatory standards I came across the problem of finding a source that I could cite of concise, worldwide accepted industry geophysical terms.

So far I know Schlumberger Oilfield Glossary, SEG Wiki, SPE PetroWiki that give some information on some terms. In practice I need something like this definition in SEG Wiki for seismic crooked lines. Although in this case I don't think the term is well defined.

I am looking for a worldwide industry accepted glossary that I could rely on and cite. The broader it is the best will be for having less problems in future. Where would be the best place to find such source of information? Any other suggestions will be welcome.

Explanation: Sheriff's Encyclopedic Dictionary is the closest thing to a canonical text, but the Schlumberger glossary is more up to date.

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**Sheriff's _Encyclopedic Dictionary_ is the closest thing to a canonical
text, but the Schlumberger glossary is more up to date. **

[ Sheriff ](http://wiki.seg.org/wiki/Dictionary:Sheriff's_Dictionary) is a
scientific text, whereas the Schlumberger glossary is a little more generally
accessible, but neither is comprehensive. Sheriff is especially poor on recent
advances. On the plus side, you can edit it, if you're an SEG member.

After those two, Wikipedia is probably your next best bet.


Question:
I need US monthly climate data for the years 1992-2012. It would be great to get down to a county level, but by state would be just fine. Every site that I go to inevitably kicks me to the NCDC, but I cannot make sense of their data.

For example: the .csv sample data for GHCN Monthly Summaries lists EMXT (extreme maximum temperature) for each month of 2010 in Petersburg, ND. July had an EMXT of 317. I've been through the documentation, but I can't figure out what that number is supposed to mean. I know it wasn't 317F or C in ND at any point. Did they add all the temps up? Was it around 10C every day of July 2010? But why would you do that? The .PDF data looks like actual temperatures, but I need a lot of data: .CSV is ideal; .PDF is really not useable for the amount of data I am going to manipulate.

What am I missing? Or is there another way to get this data?

Explanation:
Air Temperature (all units in Fahrenheit on PDF monthly form and tenths of degrees Celsius on CSV or text)
EMNT - Extreme minimum temperature *
EMXT - Extreme maximum temperature *

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The [ documentation linked from the datasets page
](http://www1.ncdc.noaa.gov/pub/data/cdo/documentation/GHCNDMS_documentation.pdf)
states:

> Air Temperature (all units in Fahrenheit on PDF monthly form and **tenths of
> degrees Celsius** on CSV or text)
>  EMNT - Extreme minimum temperature *
>  EMXT - Extreme maximum temperature *

The [ Petersburg data
](http://www1.ncdc.noaa.gov/pub/data/cdo/samples/GHCNDMS_sample_ascii.dat)
looks plausible under this interpretation (EMXT −3.9°C to 33.9°C over the
year).


Question:
This is a question on methodology. But I have 4d temperature and salinity gridded data (time, depth, lat and lon). The time is in monthly time steps. How would I get the annual harmonics of temperature and salinity using a periodicity of 12 months:

The equation is:

Var(t,z,y,x)=A(z,y,x)∗cos[(2πt/P+ϕ(z,y,x)]

Where A
 is the amplitudes of the annual component, where var
 is either temp or salinity. ϕ
 is the phase angle which determine the time when the maximum of the annual harmonic occurs. And t
 varies from 0 - n months (however long the time series is).

We can isolate A(z,y,x)
 just with algebra, but the issue is finding the phase angle where the maximum of the annual harmonic occurs.

Do you you need to take a fourier transform of monthly means (January - December), or do you take the FT of the entire time series but just look at the power spectrum at 12 months... I am using Python, and taking the fourier transform is no problem. I just don't know how to treat the data to obtain the phase angle where the maximum of the annual harmonic occurs. What might be the steps to find the annual h

Explanation: Using the theory of Trigonometry/Simplifying a sin(x) + b cos(x), we can determine the  annual harmonics of temperature and salinity data

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With a little bit of math:

$$ A * \cos [ (2 \pi t/P + \phi] = a\sin(2\pi t/P)+b\cos(2\pi t/P)$$

Then, the amplitude is:

$$A=\sqrt{a^2+b^2}$$  and the phase is  $$\phi=\arctan{\frac{b}{a}}$$

[ https://en.wikibooks.org/wiki/Trigonometry/Simplifying_a_sin(x)_%2B_b_cos(x)
](https://en.wikibooks.org/wiki/Trigonometry/Simplifying_a_sin\(x\)_%2B_b_cos\(x\))


Question: Which plant is the most efficient in making oxygen for it's weight? I want to think it is the greenest plant with more leaves and least trunk in full sun?

Explanation: Algae, tiny plants in water, create green slime on rocks and produce abundant oxygen, sustaining aquatic life globally.

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I just read an article saying that algae produces more oxygen than all the
plants in the world!! Edit: [ https://www.nps.gov/romo/learn/nature/algae.htm
](https://www.nps.gov/romo/learn/nature/algae.htm) First paragraph last lines


Question: Quite simply what is the highest point above sea level that is right on the equator, I figured it would be a mountain in the Ecuadorian Andes but the Kenyan highlands look to be a likely candidate as well. I've tried to find it but I simply can't find a map that has the equator and the altitude in a highly accurate format and resolution anywhere.

Explanation: Volcán Cayambe is the furthest point that on the equator we can find.

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I would assume that's the highest point on the equator you talking about, so
The highest point on the Equator is at the elevation of 4,690 metres (15,387
ft), at 0°0′0″N 77°59′31″W, found on the southern slopes of [ Volcán Cayambe
](https://en.wikipedia.org/wiki/Cayambe_\(volcano\)) [summit 5,790 metres
(18,996 ft)] in Ecuador. This is slightly above the snow line and is the only
place on the Equator where snow lies on the ground.


Question:
Is wind just mainly nitrogen particles moving in one direction?
The air is composed of mainly nitrogen. Therefore, when you feel wind, is it mainly nitrogen particles hitting you that, on average, are moving in one direction?

Explanation: Behind wind formation, is a theory of brownian movement of molecules.

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In a nutshell, you're a little bit right. The Air pressure is essentially
Nitrogen and Oxygen molecules hitting our bodies, but that's true with and
without wind.

wind is more easily explained from the macro-scale not the micro-scale. It's
not molecular behavior but governed by forces like high and low pressure
systems and weather, or, fans if you're indoors.

[ The Brownian ](https://en.wikipedia.org/wiki/Brownian_motion) motion of
molecules is pretty consistent like 3d billiard balls, though velocity of the
molecules increases with temperature. This is kind of what air molecules
movement looks like:

[
![https://upload.wikimedia.org/wikipedia/commons/6/6d/Translational_motion.gif](https://i.sstatic.net/BAEQ9.gif)
](https://i.sstatic.net/BAEQ9.gif)

Wind is, in a nutshell, the entire box moving, not individual particles
changing direction, but it could probably be looked at either way.

If all the air molecules, by some strange coincidence, all moved in the same
direction 2 things would happen. One, the air would get very cold as
temperature is essentially agitated molecules moving or vibrating against each
other, and two, the wind speed would be over 1000 kph. Roughly the speed of
sound. Fortunately this kind of thing is so statistically improbable it
essentially never happens.


Question:
My understanding of climate change is that a large increase in human-caused CO2 emissions is likely to lead to large change in the Earth's climate through a global warming effect. Scientific consensus appears to me to be that if we make similarly large reductions in CO2 emissions, we can reduce the magnitude of the consequent warming.

I also understand the climate to have many non-linear mechanisms whereby the link between emission and warming isn't at all straightforward - and so we can only talk about broad averages and so forth, rather than make specific weather predictions.

So is it always true that a reduction in emissions will - on average - cause a reduction in the global warming effect, however small? Or does the existence of tipping points or any other factor mean that only large reductions can make a difference now and any lesser reduction will be pointless?

My intuition says that smaller cuts in emissions should still be preferred to no cuts at all, as I imagine that they would reduce the peak warming and/or delay the peak for longer and/or reduce the eventual recovery time. Perhaps not by as much as we might prefer, but still better than nothing. But perhaps my intuition is off.

Explanation: the relationship between emissions and climate change is complex due to the non-linear mechanisms in the climate system.

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Yes, because carbon emissions [ are like a budget
](https://en.wikipedia.org/wiki/Emissions_budget) . The Mercator Institute has
one of the most commonly cited [ analyses of our carbon budget
](https://www.mcc-berlin.net/en/research/co2-budget.html) :

> the atmosphere can absorb, calculated from end-2017, no more than 420
> gigatonnes (Gt) of CO  2  if we are to stay below the 1.5°C threshold.
> Annual emissions of CO  2  – from burning fossil fuels, industrial processes
> and land-use change – are estimated to be around 42 Gt per year, the
> equivalent of 1,332 tonnes per second. With emissions at a constant level,
> the budget would be expected to be used up in less than seven years from
> now. The budget for staying below the 2°C threshold, for its part, of
> approximately 1,170 Gt, would be exhausted in about 25 years.

So, just like a household or business budget, small (but persistent)
reductions in spending/emissions do make a difference in the long run.


Question:
I've been reading up about Gravitational Models and Spherical Harmonics.

Where I first read about them is in this scholarly article on Autonomous navigation with Gravity Gradients. It talks about Gravity Models being of order x and degree y.

What does order and degree mean in this circumstance? Is it something to do with the Lagrangian Polynomials used in the models?

Another example is found here which states that EGM2008 is complete to spherical harmonic degree and order 2159

Explanation: Spherical harmonics are mathematical functions used to describe patterns on a sphere. The degree (l) and order (m) of a spherical harmonic function determine its properties. The order represents the number of waves when moving around the sphere at a constant latitude, while the degree, taking the order into account, indicates the number of zero crossings when traveling from pole to pole.

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Citing from [ Wikipedia ](https://en.wikipedia.org/wiki/Spherical_harmonics) :
$Y_l^m$  is called a spherical harmonic function of degree  $l$  and order
$m$  . If we take the real part of the spherical harmonics only, there is a
nice visual explanation for order and degree.

The order  $m$  is the zonal wave number, that is how many waves we count
walking around the sphere at constant latitude. The degree is a little more
difficult to interpret, because we need to take the order into account:
$l-|m|$  is the number of zero crossings if we walk from pole to pole.

Below you can see an example for  $l=3$  and  $0\leq m \leq 3$  (keep in mind
that in order to count the number of zonal waves you also have to walk around
the "back" of the sphere which you can not see in the picture): [ ![enter
image description here](https://i.sstatic.net/1sGCD.png)
](https://i.sstatic.net/1sGCD.png)


Question:
I just found a video on sedimentary rock formation, and to my surprise, it stated that this only could occur in water! I always thought that any layer of matter, if buried deep underneath more matter, could form a sediment and become new rock. Am I completely wrong, or was the video simply not covering all bases?

I did Google it and check Wikipedia, but with my limited knowledge of the field, the results were inconclusive.

Explanation: While not all sediments require water for deposition, water plays a crucial role in the formation of most sedimentary rocks through processes like compaction, diagenesis, dissolution, and cementation.

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**Not all sediments are deposited in water, but water is important in the
formation of most sedimentary rocks.**

If we're just thinking about the deposition of the sediment, then we don't
necessarily need water. Some counterexamples are:

  * [ **Aeolian sandstones** ](https://en.wikipedia.org/wiki/Eolianite) , such as the Lower Permian Rotliegend sandstone of the North Sea. These are deposited by wind, not water.
  * Some types of [ **sedimentary breccia** ](https://en.wikipedia.org/wiki/Breccia) , which are chiefly deposited by gravity, not water.
  * [ **Tuff** ](https://en.wikipedia.org/wiki/Tuff) , which are deposited by gravity and wind, not water. They also undergo substantial compaction and lithification with or without water.

But deposited sediment does not a rock make. Once deposited and if buried,
most sediment undergoes compaction and diagenesis, eventually lithifying — a
fancy word for turning into a rock. Below the water table, the shallow crust
is saturated with (mostly) saline water, and processes like dissolution and
cementation are necessarily aqueous. So it's fair to say that water is
essential in the formation of sedimentary rocks, on Earth anyway.

###  Footnote

You were right to be skeptical, by the way; the video is introductory material
apparently intended for grade school audience, so you can't treat it like a
textbook. And you can't even take a textbook as 'truth', especially when it
comes to slippery things like definitions. Sometimes generalizations and
simplifications help, sometimes they don't.


Question: When was the first not-icy desert formed?For how long have deserts existed and which one would be the first to be created? I'm talking about arid, dry deserts, not the Antarctic or Arctic or any other icy deserts.

Explanation: Deserts have existed since at least the Permian period, but the current desert environments we see today are relatively recent, dating back to about 65.5 million years ago. The development of modern deserts is attributed to the progressive cooling and aridification of global climates during the Cenozoic Era. The oldest "modern" desert is believed to have emerged in what is now North Africa or South Asia.

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Deserts have existed since at least the Permian period (299-251 million years
ago) when the world's continents had combined into the Pangaea supercontinent.
Stretching from pole to pole, this land mass was large enough that portions of
its interior received little or no precipitation, [ according the University
of California Museum of Paleontology
](https://ucmp.berkeley.edu/permian/permian.php) .

Pangaea broke into smaller land masses which were moved across the surface by
tectonic forces, a process that both changed global climate patterns and the
climate those continents were exposed to. As a result, current desert regimes
date back to no more than 65.5 million years, according to [ this Encyclopedia
Britannica article ](https://www.britannica.com/science/desert) :

> The desert environments of the present are, in geologic terms, relatively
> recent in origin. They represent the most extreme result of the progressive
> cooling and consequent aridification of global climates during the Cenozoic
> Era (65.5 million years ago to the present), which also led to the
> development of savannas and scrublands in the less arid regions near the
> tropical and temperate margins of the developing deserts. It has been
> suggested that many typical modern desert plant families, particularly those
> with an Asian centre of diversity such as the chenopod and tamarisk
> families, first appeared in the Miocene (23 to 5.3 million years ago),
> evolving in the salty, drying environment of the disappearing Tethys Sea
> along what is now the Mediterranean–Central Asian axis.

Which would put the oldest of "modern" desert somewhere in the region of what
later became North Africa or South Asia.


Question:
Some days I can smell bad smelling exhaust 50 meters or more away from the bus stop. I think the air is usually moist those days.

Does exhaust gases linger longer if the air is moist near the ground? Is it smog I am smelling those days?

On morning 12 march it was about

Temperature: 4°C
Humidity:93%
Barometer:978 mbar
Wind:10 m/s
Looking at the data from earth.nullschool.net at a few hours before that morning I saw surface temperature of 5.1°C and 5.8°C at 1000hPa.

Explanation: When we smell something, we are inhaling gases or particles. These don't accumulate in the atmosphere due to transport, chemistry, and deposition processes. Atmospheric chemistry, involving compounds like the hydroxyl radical (OH), converts odorous pollutants into simpler chemicals we don't smell. Deposition occurs through precipitation and settling of particles. While some pollutants may take years to convert, they eventually deposit on Earth's surface. Stagnation events can trap stinky air near the ground, but overall, the atmosphere maintains a balance through these processes.

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You can see [ this post
](https://earthscience.stackexchange.com/questions/13391/where-do-bad-smells-
eventually-go/13392#13392) for a more detailed discussion, but the typical
answer to your question is air stagnation. When the atmosphere is stable,
there is little mixing, and the air can stagnate. Typically this coincides
with low wind speeds and a low boundary layer. The boundary layer holds air
near the surface like a blanket. The boundary layer collapses overnight,
becoming shallow, and grows when the sun heats the surface of the Earth. So,
in the morning, the shallow boundary layer allows less vertical mixing to
occur.

You might be noticing that on cloudy days, when clouds are low, there is
little wind and no solar heating. Air pollution has no place to go, so it
sticks around.

Another aspect is that vehicles emit more emissions under cold-start
conditions. This is because vehicles get cold overnight and take a while to
get up to normal temperature when they startup in the morning. The cold
vehicle will have a low combustion efficiency and catalytic converters won't
work as well.


Question:
I am listening to a song about volcanoes. It is called "Pyroclastic Annihilation" performed by a brutal deth/thrash metal band called "Demolition Hammer". It is from their album "Epidemic of Violence" released in 1992. The song is: https://www.youtube.com/watch?v=S_7qqsVioxo the full lyrics can be found here: https://genius.com/Demolition-hammer-pyroclastic-annihilation-lyrics

I have come across a term I do not understand.

Molten debris
Volcanic ash
Seas of boiling mud
Subrelluric forces exploding violently
Pyroclastic matter intense velocity

Is the word "Subrelluric" a geological term? If yes what does it mean exactly? What are Subrelluric forces? What do they do amidst a volcanic eruption? I couldn't find anything on the web. Perhaps this is an extremely advance term not usually used in the public world?

Explanation: Actually the "Subrellutic" is the word "Telluric", which means the earth.

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I believe what you heard is “subtelluric” where [ telluric
](https://en.wikipedia.org/wiki/Telluric "telluric") means “of the earth”.


Question:
In the mainstream media the problem of ocean level rise is presented rather... over-simplistically - ice melts -> more water flows into the oceans -> water level rises -> continents sink.

But it is in reality a complex system, it is not like pouring water in a glass... or a lake that resides on a continental plate.

Both continental and oceanic plates float on top of the mantle as both are lighter and lower density, and both exert weight and compress the mantle.

Therefore, if water is removed from continental plates by means of melting ice, the continental plate gets lighter. And when that water migrates to the ocean, the oceanic plate gets heavier. And since for every action there is equal in force and opposite in direction reaction, it seems logical that the now heavier oceanic plate will actually push the now lighter continental plate up, to some extent compensating for or possibly even reversing the change in ocean level relative to the continental plate.

So, do the estimates account for the dynamic properties of that complex system?

Explanation: Relative sea level is the sea level measured in relation to the continental crust, affected by changes in both sea level and land movements. Mean Sea Level (MSL) is the average water level over a specific period, measured relative to a fixed mark on land. MSL can change due to water volume or land movements. Long-term sea level changes include Glacial Isostatic Adjustment (GIA) caused by post-glacial land movements.

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Sea level rise estimates use changes in [ relative mean sea level
](http://www.coastalwiki.org/wiki/Relative_sea_level) . The definition being:

> Relative sea level is the sea level related to the level of the continental
> crust. Relative sea level changes can thus be caused by absolute changes of
> the sea level and/or by absolute movements of the continental crust.

In general, [ Mean Sea Level ](https://en.wikipedia.org/wiki/Sea_level) means
the 'water level when it is still' (without waves). MSL is averaged over a
determined period of time, such as a month or a year and it is measured
relative to a fixed mark on the land (benchmark).

As MSL is measured relative to land, it can change due to changes in water
volume or due to land movements. That is why we usually refer to it as
'relative sea level'.

Long-term changes of sea level are called "secular" changes and include
isostatic changes. The main reason for isostatic changes at a global scale is
the [ Glacial Isostatic Adjustment ](https://en.wikipedia.org/wiki/Post-
glacial_rebound) (GIA).

The body of scientific work related to the contributions by different factors
is extensive. For instance, I like [ Cazenave & Nerem, 2004
](https://doi.org/10.1029/2003RG000139) . Also, there is a lot of information
about [ the relative contributions of each
](https://sealevel.jpl.nasa.gov/science/ostscienceteam/scientistlinks/scientificinvestigations2013/cazenave/)
.

[ ![contributions](https://i.sstatic.net/dFSot.jpg)
](https://i.sstatic.net/dFSot.jpg) Source: [ JPL-NASA
](https://sealevel.jpl.nasa.gov/science/ostscienceteam/scientistlinks/scientificinvestigations2013/cazenave/)

There is a lot more information about the regional distribution of sea level
rise in: [ How will sea level rise be distributed across the globe?
](https://earthscience.stackexchange.com/questions/10876/how-will-sea-level-
rise-be-distributed-across-the-globe)

Also, [ here
](http://homepages.see.leeds.ac.uk/~lecimb/SOEE3410/lectures/15-Sea-level-
rise.ppt) is a good simple explanation of the factors affecting sea level.


Question:
I am a lay person in meteorology, maybe this is not the right place for my question, but I would like to ask then.

My question is simple: is there a website or institute that has integrated statistics on forecasting the occurrence of rainbows in different countries around the world?

Explanation: A rainbow is not a physical object, but an optical phenomenon caused by sunlight interacting with raindrops. It depends on your location relative to the sun and rain. Due to the refraction, reflection, and refraction of light within raindrops, a concentration of outgoing rays forms a rainbow at an angle of 42 degrees above the observer's shadow. Different people see different rainbows because each person has a unique horizon and antisolar point. Rainbows cannot be precisely measured or cataloged like lightning. However, there are resources available, including apps, for predicting and photographing rainbows.

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A rainbow is not a physical object that has a position. It is an optical
phenomena that depends on your location relative to the sun and rain. If you
are standing where your eyes can intercept the colored light, you are standing
with your back to the sun and the sunlight is reflecting on raindrops in front
of you. Someone else standing in a different location would not necessarily
see a rainbow if they looked up at the same part of the sky.

From [ University of Illinois
](http://ww2010.atmos.uiuc.edu/\(Gh\)/guides/mtr/opt/wtr/rnbw/frm.rxml) :

> According to Descartes' calculations using laws of optics, the three stage
> refraction-reflection-refraction pattern that light undergoes when passing
> through a raindrop produces a concentration of outgoing rays along a line
> that is 42 degrees above the head of an observer's shadow. This
> concentration of light rays is the rainbow that we see.

Also [ this National Geographic article
](https://www.nationalgeographic.org/encyclopedia/rainbow/print/#:%7E:text=In%20fact%2C%20no%20one%20sees,his%20or%20her%20own%20horizon.)
has a nice description:

> Viewers on the ground can only see the light reflected by raindrops above
> the horizon. Because each person's horizon is a little different, no one
> actually sees a full rainbow from the ground. In fact, no one sees the same
> rainbow—each person has a different antisolar point, each person has a
> different horizon. Someone who appears below or near the "end" of a rainbow
> to one viewer will see another rainbow, extending from his or her own
> horizon.

What this means is that a rainbow is not really a meteorological occurrence
that can be measured or catalogued, because you would get a different answer
depending on your reference point. Lightning, in contrast, is a physical
phenomena that has a precise location which can be determined and verified
from multiple points of reference.

Rainbows are photographed and archived by enthusiasts, but it's really about
artistic appreciation. While I have not looked into rainbow forecast services,
a quick search shows some interesting resources, such as [ How to Predict
Rainbows and Plan Photographs ](https://stephenbayphotography.com/blog/how-to-
predict-rainbows-and-plan-photographs/) which has a link to a [ photography
app that can plan for rainbows ](https://www.planitphoto.com/#feature) and
here is a [ rainbow app you can install
](http://www.erikscarlson.com/project/chance-of-
rainbow#:%7E:text=Creating%20an%20algorithm%20to%20predict,\(if%20that%20is%20possible\).)
on your phone.

[ How Rainbows Happen ](http://www.rebeccapaton.net/rainbows/formatn.htm) also
has a nice description (shown below) and some other useful resources. [
![enter image description here](https://i.sstatic.net/GEDyn.gif)
](https://i.sstatic.net/GEDyn.gif)


Question:
I would like to know what would happen with the atmosphere of Venus when it gets tidally locked, i.e. when one side would perpetually face the Sun.
Probably a thermal low would be at the subsolar region then.

At the surface Venus has an atmospheric pressure of 92 atm. and a temperature of 462⁰
 C.

Are there General Circulation Models or Global Climate Models that can handle such input parameters ?

If so, are there GCM users (groups, universities etc.) who could run a tidally locked Venus simulation ?

Explanation: The OPUS-V and ROCKE-3D models, based on older versions of climate models, have been utilized for studying Venus. However, more recent models, such as those mentioned in the Yamamoto et al. (2019) introduction, provide an updated and diverse range of options from research groups worldwide.

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I'm not sure of their current status, but I read some papers based on these
models a few years ago:

  * [ Oxford Planetary Unified Model System ](https://www2.physics.ox.ac.uk/research/geophysical-fluid-dynamics/research/oxford-planetary-unified-model-system) for Venus (OPUS-V), which is based on an old version of the UK Met Office climate model, HadCM3 ( [ paper ](https://doi.org/10.1016/j.pss.2016.09.001) from 2016).

  * ROCKE-3D at Nasa GISS, which is based on an old version of the GISS ModelE2‐R climate model ( [ blog article ](https://climate.nasa.gov/news/2475/nasa-climate-modeling-suggests-venus-may-have-been-habitable/) and [ paper ](https://doi.org/10.1002/2016GL069790) from 2016).

It looks like the introduction of [ Yamamoto et al
](https://www.sciencedirect.com/science/article/pii/S0019103518304846) (2019)
has a more up-to-date summary of the current set of models, and there's quite
a healthy selection from groups around the world.


Question: Researchers who are involved in study of life on Mars are saying that there might be multicellular life present on Mars, today or in the past. Which traces, markers or environments on Mars could support this hypothesis and how it will be investigated?

Explanation: The Mars 2020 mission aims to search for signs of past microbial life on Mars. It has two main objectives: finding fossils of extinct life forms that may have existed around 3-3.5 billion years ago when Mars had conditions suitable for life, and searching for present-day bacterial life on or near the Martian surface. The mission will focus on sampling rocks from potentially lifebearing areas, such as old lake beds like the Jezero Crater, known for its clay-rich delta formation.

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One of the next big missions to Mars, named [ Mars 2020
](https://mars.nasa.gov/mars2020/) is planned to depart from Earth to Mars
during late July 2020. This mission involve a [ very capable rover
](https://mars.nasa.gov/mars2020/mission/rover/) , like [ Curiosity
](https://mars.nasa.gov/msl/home/) on steroids.

From the mission site:

> The mission takes the next step by not only seeking signs of habitable
> conditions on Mars in the ancient past, but also searching for signs of past
> microbial life itself.

This mean that there is two important objective:

  1. to find **extinct life forms** , such as assuming there was conditions a long time ago permitting lifeforms to exist on Mars, likely 3-3.5 Billion years from now or so, in other words, fossils. Why 3-3.5 Gy ago? This was during Hesperian geological epoch when water was likely a major agent in forming channels lakes and rivers, thus with atmospheric and ground conditions possibly permitting the existence of life back then.
  2. to find **extant life forms** such as bacteria that are existing presently on Mars surface or near surface.

One component of the mission is to sample rocks that are likely lifebearing,
analyze and store for a later pickup by a further mission. Lifebearing rocks
in that case may be found as old lake beds, for example iron rich lacustrine
mudstone.

Lacustrine mudstone is obviously originating from depositing fine sediments
over a lake floor, a stable environment through a long time, as shown by
layers like [ this ](https://www.nasa.gov/jpl/msl/pia19074) (pictured by
Curiosity's MastCam in 2014). And iron rich is important as this chemical
arrangement is favoring and helping the preservation of microbial lifeforms.

[ ![Jezero Crater, Mars](https://i.sstatic.net/lyLXK.jpg)
](https://i.sstatic.net/lyLXK.jpg)

Source: [ https://www.nasa.gov/image-feature/jezero-crater-mars-2020s-landing-
site ](https://www.nasa.gov/image-feature/jezero-crater-mars-2020s-landing-
site)

As can be seen in the picture, the big circle (as a crater) in the center of
the delta is named the Jezero crater and is the target landing site for Mars
2020. This delta was formed due to water flowing in a lake; clay rich
deposited were detected in the area. The crater is exposing deeper (early)
layers in the delta, making this an ideal exploration site to look for extinct
or extinct life.


Question:
Is there a package for R to plot Schmidt nets, like it is done in geology?

So far, I only know software like Stereonet. However I think it would make a lot of sense to handle these data in R, to have so much more possibilities in calculations and statistics.

Explanation: While there is no specific package in R dedicated to plotting Schmidt nets for geology, the RockFab package in R can be a useful tool for geological analysis and visualization.

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You might try the [ RockFab package
](https://cran.r-project.org/web/packages/RockFab/) . I am not a structural
geologist but I use other R packages for geological endevours.

[ Documentation ](https://cran.r-project.org/web/packages/RockFab/RockFab.pdf)
.


Question:
Generally speaking, iron is considered to be a very common resource. But I cannot find any evidence that there is any of it at all in New Guinea. Copper and gold, yes. Even nickel and cobalt. Iron on the nearby island of Bougainville. But no mention of iron.

Are there really no useful iron deposits on the entire island? Or is it more like, there are some, just not big enough to make the news?

Explanation: The island of New Guinea is divided into two entities: Papua New Guinea in the east and the Indonesian province of West New Guinea in the west. No known hard rock deposits of iron ore have been reported on the island. In Indonesia, the top five iron ore mines as of 2020 are the Yiwan Mine in South Kalimantan, the Gag Island Project in West Papua, the Pomalaa Mine in South East Sulawesi, the Pakal Island Mine in North Maluku, and the Nalo Baru Mine in Jambi. These mines produced varying amounts of iron ore in 2020.

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The island of New Guinea is effectively divided into two entities, the country
of Papua New Guinea occupies the eastern half and the Indonesian province of
West New Guinea occupies the western half.

No known **hard rock deposits** of iron ore have been reported for anywhere on
the island.

In Indonesia, as of 2020, the [ top five iron ore mines ](https://www.mining-
technology.com/marketdata/five-largest-iron-ore-mines-indonesia-2020/) are:

>   1. Yiwan Mine
>

>
> The Yiwan Mine is located in South Kalimantan. It is owned by Yiwan
> Mining.The mine produced an estimated 2.547 MTPA of iron ore in 2020.
>
>   2. Gag Island Project
>

>
> Located in West Papua, the Gag Island Project is owned by Indonesia Asahan
> Aluminium. The surface mine produced an estimated 1.06 MTPA of iron ore in
> 2020. The mine will operate until 2047.
>
>   3. Pomalaa Mine
>

>
> The Pomalaa Mine is located in South East Sulawesi. It is owned by Indonesia
> Asahan Aluminium and produced an estimated 0.943 MTPA of iron ore in 2020.
>
>   4. Pakal Island Mine
>

>
> The Pakal Island Mine, owned by Indonesia Asahan Aluminium, is a surface
> mine located in North Maluku. The mine produced an estimated 0.515 MTPA of
> iron ore in 2020.
>
>   5. Nalo Baru Mine
>

>
> Owned by Earthstone Holdings, the Nalo Baru Mine is a surface mine located
> in Jambi. It produced an estimated 0.027 MTPA of iron ore in 2020. The mine
> will operate until 2031.

As you state in our question, there a small number of hard rock deposits on
smaller islands that are part of Papua New Guinea.

The only iron ore resource that occurs on the island of New Guinea are
deposits of [ iron sands ](https://mine.onepng.com/2021/11/pngs-orokolo-by-
iron-sand-project.html) . They lie on the [ southern coast of PNG
](https://mayurresources.com/minerals/) , around the coast of the Gulf of
Papua. Currently, the main deposits are at Amazon Bay in the south east and
Orokolo at the top of the gulf.

[ ![enter image description here](https://i.sstatic.net/1NJB1.png)
](https://i.sstatic.net/1NJB1.png)

It appears the iron sands are associated with other mineral sand minerals that
are zircon rich, with some deposits having titanium and others vanadium. The
iron sands are composed of [ magnetite
](https://en.wikipedia.org/wiki/Magnetite) .


Question:
I am new with Python so please be kind. I want to download data from ERA5 and so far I have installed the CDS API package and followed all the instructions from https://cds.climate.copernicus.eu/api-how-to

I have my main file ready to use but I get an error about the configuration file. I know that this file should contain the following:

url: https://cds.climate.copernicus.eu/api/v2
key: {UID}:{key}
verify:0
I have created a text file and a configuration file with this info and I have placed them in the following address (as required by the error I get in python):

C:\Users\username\.cdsapirc
However, I still get the same error. What I am doing wrong? Do I need to create a different type of file? Do I need to write the user info in a different way?

Exception: Missing/incomplete configuration file: C:\Users\username/.cdsapirc
By the way, I'm using a windows computer.

Explanation:
Five steps to download the ERA5 data:Navigate to 'C:\Users\username' (or you can just move it later).
In Command Prompt, write 'type nul > .cdsapirc' and press Enter.
Right-click the file and press 'Edit with Notepad++' (probably works with other programs).
Paste the text that you already mentioned (key, etc).
Save and close the document.

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I had the same problem but have just found the solution after an hour or so of
trawling through forums! The problem was that the code 'api.py' could not find
the '.cdsapirc' file. The file type has to actually be 'CDSAPIRC' and not a
'txt' file. The icon for the file will then be displayed in your folder as
blank and the name will be '.cdsapirc'. I found the solution on here: [
https://www.wikihow.com/Create-and-Delete-Files-and-Directories-from-Windows-
Command-Prompt ](https://www.wikihow.com/Create-and-Delete-Files-and-
Directories-from-Windows-Command-Prompt) . I created the file using the
following steps:

  1. Navigate to 'C:\Users\username' (or you can just move it later).
  2. In Command Prompt, write 'type nul > .cdsapirc' and press Enter.
  3. Right-click the file and press 'Edit with Notepad++' (probably works with other programs).
  4. Paste the text that you already mentioned (key, etc).
  5. Save and close the document.

Hope that works :)