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1500 questions
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Earthquakes at plate boundaries
I was looking into tectonic plate boundaries and earthquakes with pictures like these
One thing that is quite obvious is that some of the plate boundaries have very thin zones of earthquakes, whereas the zones near India, Chile, Australia,.. are…
M. Kim
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How would a Mars rover identify a microbialite fossil?
I recently read of a company in Canada using robotic technology to study freshwater microbialites. Their claim is that greater understanding of terrestrial microbialites could help in the search for extraterrestrial microbialite fossils (if they…
Mark Rovetta
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2 answers
Why is Egypt so dry?
If you look at this wind map (for July, but following the link you can also view other months):
you will see that Egypt gets its air from the Mediterranean sea. During other months it could get less moist air, but still from the same direction.
If…
user6130990
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Large scale structures in the Sahara – what are they?
In Google Earth we can see some very clear lines in the Sahara. In the screenshot below you can clearly see these lines starting at the top going southward, then gently curving westward towards the bottom.
What are these structures and how were…
Desert
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What geophysical instruments should I use to detect water without drilling?
How can one detect (preferably artesian) aquifers nowadays that a lot of sensors are available? Should I use ground-penetrating radars, neutron detectors, or any other advanced devices? Can seismic imaging be used to characterize the extent of the…
Deer Hunter
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2 answers
Can human activity affect volcanoes?
As part of a course on Natural Disasters, I have a group presentation in which we focus on a specific natural disaster. One of the questions we have to address is how human activity may have affected the geographic area and/or the disaster. The…
silvascientist
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1 answer
Rate of underground formation of carbon-14 by neutron capture
Carbon-14 constantly forms in the atmosphere due to neutron capture by nitrogen-14 and subsequent emission of a proton. Other less frequent mechanisms involving neutron capture by carbon-13 or oxygen isotopes also exist, as well as radium decay, as…
DavePhD
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1 answer
Carbonate reef not horizontal in seismic section?
Carbonate reefs usually appear as homogeneous bodies surrounded by sediment layers in seismic reflection data, but in the figure below the high amplitude reflection from the top of sediment (layer 2 at 0.3-0.34 seconds) is not horizontal yet the…
Don Sangione
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1 answer
How to determine the transmissivity of a system of rocks and faults from the stationary drawdown pattern?
I have a dataset containing high frequency measurements of the hydraulic head at different locations in a 5x6km area. Also known are the precipitation, evaporation, and pumped discharges from a number of wells (unfortunately only monthly totals for…
hugovdberg
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1 answer
What is the difference between the freezing level and 0 C isotherm in NOAA's GFS?
I'm playing around with NOAA's GFS forecast data and I see that it contains both a "0 °C isotherm level" and a "Highest tropospheric freezing level".
Could someone tell me the difference between these two levels? I'd assume they are the same except…
os1
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10
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2 answers
Technique to delete spin-up frames from WRF
I'm a user of WRF V3.5 aiming at meteorological simulation.
Sometimes, I'll run the model for a long period.
My attempt
I split the long period(e.g 1 year) into serval short ones.
For example:
## WPS namelist.wps
start_date =…
Han Zhengzu
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10
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2 answers
What causes a rainbow, its colours and its shape?
What is the cause of rainbows? Do they appear due to rainfall or any other natural phenomenon. What makes it form a semi-circle in the atmosphere and its colours?
John
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Does natural plant decomposition release more greenhouse gases than burning
I understand that all plant matter releases CO2 as it decomposes and also when it burns in, for example, a forest fire. My assumption, upon which this question is based, is that the CO2 release is the same in each case.
My main question is, what…
Puffin
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2 answers
What keeps the different gases mixed in the atmosphere?
Consider a gas centrifuge holding two different gases. After spinning for a while, the heavier gas will move to the outside, and the lighter gas will be on the inside. In other words, we have stratified the gases.
Why hasn't this happened in Earth's…
DrZ214
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10
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1 answer
Converting grid resolution from degrees to kilometers
I am curious how can one have an idea of grid resolution. How much is the distance resolution in km of a grid with resolution of 0.5 deg x 0.666 deg?
Jahangir
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