# All Questions

4,450 questions
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### Rayleigh waves generation

Good day, I do not fully understand the physical mechanism of formation of Rayleigh waves at the free surface. While their derivation is quite clear and obey free-boundary conditions, it is not clear ...
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### Can someone tell me what this stone is?

My father found it in the Himalayas 20 years ago. It was unique looking stone in a rock-fall. It is 6-7cm in diameter, well rounded. It has dark almost black outer stone-like layer and metal center. ...
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### Tectonic Plate Movement

I have been unable to find a clear answer to the following basic question. How are continental shelves formed - What type of boundary occurs (convergent, divegent, oceanic to continental, etc) and ...
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### mountain database of elevation and distance from saddle (as a proxy for gradient)

I'm interested in doing data visualization projects about mountains. We have data from http://www.peaklist.org/ultras.html complied by Aaron Maizlish (Who we tried to contact but not sure of his ...
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### can you help identify my crystal

it is green is color With silky luster Hardness is about 7 Found in lake Elsinore mountain s
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### Found this rock in Cambridge, uk . on a field recently been ploughed

I found this rock while out walking it’s of a matallic Luster and black in colour, Smooth to the feel but bumpy in places, with one small rough patch shown on the picture and no colour change ...
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i found this while walking dog it’s very heavy for its size and itsa about 35mm by 25mm by 20mm
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### What are the main obstacles facing large-scale underwater farming? [on hold]

Recently I read about OceanReef's Nemo's garden, which is growing terrestrial plants underwater inside a dome on the seefloor. I did not found any other company doing it. If it is that good as it is ...
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### When sea level rises, does the increased ocean area cause the earth to cool down somewhat?

When the sea level rises, more of the planet's area is watery and less of it is land. Does this change in surface condition result in a change in global warming, such as a decrease in the net ...
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### How are minerals classified?

What is exactly done to classify minerals in Earth Sciences such as Geology? How can it be known if one mineral is the same of another should they be visually different?
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### Help identifying rock [on hold]

I found this rock near a creek bed on the Cumberland plateau about 30 miles north of chattanooga. There area is coal bearing. It has odd knobs and a cavity that goes through it. Seems moderately ...
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### Can you identify my rock [on hold]

Found this crystal it's a redish brown
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### Why do climate experts from the UN/IPCC rarely mention Grand Solar Minimum?

I've read many papers about Grand Solar Minimums and Glassberg Minimums, known to science for very long time, studied and monitored with much of our Public Funds. History shows solar activity is the ...
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### Where can I find archived night microphysics images from EUMETSAT? I

I want night microphysics RGB composite from EUMETSAT. I'm looking for archived images. I tried finding them on EUMETSAT's data center page. Data from different channels of SEVIRI is available but ...
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### Is water actually blue or is it transparent?

This is my first post on StackExchange and I would like to ask a question: Is water actually blue or is that just the reflection of the sky?
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### Rain Shadow Effect on the Andes Mountains [on hold]

You are about to depart on a trip to the Andes mountains in Brazil to help local foresters assess the more fertile soils for growing production forests. Although you have never traveled to the area, ...
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### Signatures of acid rain at KT boundary

I read in Walter Alvarez' book T. Rex and the Crater of Doom that the Earth's collision with the large meteor leading to the K-T extinction catalyzed the reaction of atmospheric oxygen and nitrogen ...
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### How to plot the data only inside the polygon in matlab? [on hold]

We can plot data with polygon in matlab as ...
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### What is the technical term for the amount of water within the surrounding enviornment?

This may seem an obvious question but I am unable to understand what the technical term for the surrounding water of an environment is, specifically surrounding a person/animal within that environment....
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### Are there seamounts as close as 100 m to the water surface and not inside any Exclusive Economic Zone?

I did not find any seamounts as close as 100 m to the water surface (100m from the mean surface level at the location of the mountain) that are not part of any Exclusive Economic Zone (EEZ.) Do any ...
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### Why are pyroclastic flows ground-bound?

This bugged me for a while: Pyroclastic flows are fast (up to 700 km/h (430 mph) according to Wikipedia) and typically roll down the slopes of a volcano. E.g. here https://www.youtube.com/watch?v=...
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### Physics student looking for good modern literature reviews on global ecology [on hold]

I'm a nature-loving physics student looking to get into ecology. I'd like to understand as much as I can about modern problems in ecology such as the effect of climate change on atmospheric ...
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I found this rock along the Illinois river basin in cave junction, oregon. It was laying on the top layer of a massive beach of rock. It's shape is what drew me too it, then after closer inspection ...
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### What would be a reasonable set of thresholds for flood severity classes?

When working with extreme hydro-meteorological events, flood in particular, it is common procedure to classify each event by its return period/recurrence interval. This probabilistic measure has the ...
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### What causes the differences in the rarity of Calypso Bulbosa amongst different areas?

In 1864 John Muir was hiking in the swamps of Canada when he came across the Calypso Borealis (also known as Calypso Bulbosa). The plant grows in damp and colder climates, mostly in North America. ...
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### Method to determine Tmax 95th percentile in a climate data

I am analyzing the effect of extreme weather on milk production (Panel data). I am looking at direct effects and indirect effects of weather on animal (milk production). Regarding extreme weather, I ...
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### Metallic Balls Found in Sandstone or Mudstone Layer

Found metallic balls of some type of metal ore surrounded by yellow mudstone the metallic balls crush easily into a fine gray powder. The gray balls are situated between sandstone layers in a soft ...
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### Where can I find a list of snow fall recording stations in my zip code?

Where can I find the locations on snow fall recording stations in a particular county or zip code? Is there a way that I can find an hour by hour history of snow fall? That is easy to do for water ...
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### How to control output precision when running WRF?

I am very new in this area and wondering if anyone can answer my following questions: I am running WRF (4.0.3, ideal) to study rounding and truncation. I use the NCL (6.5.0) print command to access ...
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### How to strong winds cause baroclinic intensification in the upper ocean?

Below is an excerpt from The Biology of the Indian Ocean, Bernt Zeitzschel, Sebastian A. Gerlach The more vigorous atmospheric and oceanic circulation during the SW monsoon causes not only the ...
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### Please can anyone recommend a good website (or book) for identifying rocks from New Zealand?

We're finding lots of sea-smoothed rocks at the beaches, and my kids are keen to find out what rocks they are. I'm keen on a site that has good photos and easy explanations for what they are. Much ...
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### Identify Petrified Wood [closed]

Many years ago I was given, what I was told is, petrified wood. However, I really have my doubts. Is there a way to tell if it is since I have been storing it for all this time. Thank you
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### Can anyone tell me the name of this stone? [closed]

Can anyone please tell me what this stone is? Any other information on it would be helpful as well. Thank you!
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### soil that is dried (no pore space) weight?

How much would 1 m3 of an ideal mineral SOIL that has been completely dried (all pore space is empty) weigh in Mg on Earth? Answer = ______ Mg
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### What structure of fossil plants can be measured by scientists to estimate the $CO_2$ in the earth’s atmosphere prior to a million of years ago? [closed]

Why is this feature of plants a good way of estimating how much $CO_2$ was in the Earth’s atmosphere?
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### How can shake amplitude influence the damping ratio and resonant frequency of a soil base structure?

I have performed an experiment using a shaking table to simulate the response of a soil base structure to an earthquake. A multi-floor structure was placed on a sand (90% relative density) bed and the ...
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### what kind of rock is this? I found it on the beach in white rock British Columbia? [closed]

Here are the front and back pictures:
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### What is this rock it is dark dark blue? [closed]

This is really weird tell me what it is.
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### What is in this rock?

There were many, many examples of this, my photo simply shows a situation where I had even light and time to take a photo without making anyone wait for me. The basic rock is obviously sandstone. ...
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### The Tambora eruption caused the “Year without a summer”. How much would such an eruption today affect the output of solar pv on a global scale?

Are there any estimates for the reduction of global solar insolation at the Earth's surface that a Tambora scale eruption would bring? If our electrical power generation became heavily reliant on ...
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### I found this near Charmouth, UK. Seems to be metallic

It's somewhere between 5.5 and 7 on the hardness scale Feels very heavy Cold to the touch Doesn't clean up with water, vinegar or alcohol Small bumps on the surface all over
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### Identify rock found on beach in Florida [closed]

This rock was found in Florida on the beach on top of the sand. There were no others found. Color of rock is white, the outer rim is clear (see through) the inner layer is solid. The inner layer is ...
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### Undergraduate Geology to Atmospheric Science

I am curious as to the possibility of transitioning to Atmospheric Sciences in Graduate study after obtaining a bachelors in geology. I am studying geology, but will have the equivalent of a minor in ...
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### Could this rock be Basalt?

This rock is 2 3/8", weighs 71 grams has a density of 2.958,I tested the density a few times and its always 2.958, has a hardness of 6-7 almost clear streak test, I tested the streak again and I would ...
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### Identify rock, found in Florida

Round with crystal looking around it, hard. Seems to have layers in the center. The inside is smooth and the outside layer is textured. The white layers go all the way through the rock. Found on the ...
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### What are the ranges of natural (or pre-industrial era) levels of CO2 in the atmosphere in ppm and tons?

Are the levels of natural (before the industrial revolution) levels of CO2 and ppm known? Also as a related question, should the "natural" levels be considered before the industrial revolution or ...