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1500 questions
8
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2 answers
Did the surfaces of the oceans freeze over entirely during the snowball Earth periods?
According to the snowball Earth theory, all of Earth froze over at least once (possibly twice) in the far past. However, Wikipedia says that there are opponents of the theory who state that tropical portions of the oceans were not entirely covered.…
HDE 226868
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8
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1 answer
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,…
8
votes
4 answers
Are craters on Earth covered by vegetation?
When you look at other planets and moons in our solar system most of them have lots of craters. If Earth had no vegetation and water would it also look like this image of Charon?
Image Credit: NASA/JHUAPL/SwRI
Marina Dunst
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8
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3 answers
Seeking details for the "historical rate" of arable land loss
In doing research on the issue of desertification (aka land degradation) I keep running across the same basic sentence but no source or detail to support or clarify it:
"Arable land loss is estimated to be at 30 to 35 times the
historical…
O.M.Y.
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8
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1 answer
What modelling approaches are used to predict the aurora?
Are there any resources (books/links) that discuss the mathematical tools and methods used to forecast the aurora borealis activity in a particular location?
I see many websites that claim to predict aurora, but are there any open source code that…
Victor
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8
votes
2 answers
How accurate is a tipping-bucket rain gauge?
My question is simple - how accurate is a tipping-bucket rain gauge?
I have read about what causes the errors (wind, bucket mechanics for extreme events, ...) and I know the accuracy is strictly related to the rain rate, in the sense that, e.g., TB…
natario
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8
votes
0 answers
Monitoring air pollution with Landsat satellite data
I'm trying to build an air pollution model. So far I have built one for point sources. Now I'm looking at monitoring air pollution with satellite images, based on the idea that every basic pollutant somehow reacts with EM.
What is a sufficient…
ABCD
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8
votes
2 answers
Why is earth's axis tilted?
Why is the axis of earth tilted? It can't possibly be that the Northern hemisphere is larger causing it to be pulled toward the sun, because then it would always be summer in the N hemisphere and winter in the S hemisphere. If the cause for the…
tux
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8
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1 answer
How to model bed load transport in channels of non-rectangular cross sections
All the formulas presented in the relevant technical literature refer to channels of rectangular cross section — the formulas assume a constant depth of flow right across the channel section.
I need to calculate the bed load in a channel of roughly…
Jailcu45
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8
votes
2 answers
Why is the Yarkant River braided in the Pamir mountains?
The formation section in the braided river Wikipedia says that very erodible soil causes braided rivers. Intuitively, a rising mountain range like the Pamirs would not be easily erodible.
The Yarkant changes so abruptly, I'm curious what special…
12345678910111213
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8
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2 answers
Earth Science Search Engine
After scirus is closed, which search engine do you all use?
I know of Arxiv, and ADS, which only partially overlaps with Earth Science related issues. Any other recommendations would be appreciated.
Sean
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8
votes
2 answers
Measurement of groundwater levels
There are numerous measurement systems available for measuring groundwater levels (head / stage). What period of time should measurements be collected in order to draw solid conclusions about the average groundwater level, min/ max, trends, etc?
I…
Timror
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8
votes
1 answer
What is the concentration of silver in tap or freshwater in the United kingdom
Can anyone tell me the concentration of silver in uncontaminated water ways, or treated tap water in the united kingdom? sources would be desirable too
user309
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8
votes
1 answer
Why are the Little Colorado River and Havasu Creek blue?
In Grand Canyon there are two side streams that carry heavy carbonate loads and deposit travertine along their lengths. The Little Colorado and Havasu Creek both rise from springs a few miles above the river and are separated by over one hundred…
Brian
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8
votes
1 answer
What is the effect of rising sea level on measurements of elevation?
If the earth's mean sea level rises, I assume that requires humans to adjust current measurements of elevation? For example, Mt Everest would no longer be 8,848 metres above sea level. Is there a more stable universal way to measure elevation such…
Adam
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