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1500 questions
18
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Why is there Uranium in Earth's Crust?
Uranium's density is greater than most elements, so you would expect it to settle to the bottom of a volume of fluid. In the case of the Earth, which was molten in the beginning, you might then expect uranium to have settled to the core.
What…
Danubian Sailor
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What is the pressure at the center of the Earth?
In the question Does gravity increase the closer to the core you get?, it was determined that gravity reduces to zero at the center of the Earth. That is logical.
However if pressure is proportional to mass and gravity, then would pressure also…
ralph ellis
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How do I explain why the Tibetan plateau is colder than lowlands at similar latitudes?
A common layman explanation for why does it get colder to higher elevations (considering only the troposphere here) qualitatively boils down to The Sun heats the Earth's surface and the Earth's surface heats the atmosphere. I remember that, every…
gerrit
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18
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Does the US National Weather Service use Celsius or Fahrenheit?
This tweet from the National Weather Service in LaCrosse, Wisconsin, USA says:
We have officially hit -30 here at the NWS La Crosse office as of 520 a.m. The wind chill is -54. Be sure to dress appropriately if you're heading out for the day.
The…
uhoh
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18
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Why is there a line of volcanoes along the northwest coast of North America?
Mount Hood in Oregon is a dormant volcano, and in Washington Mount St. Helens and Mt. Ranier are both active volcanoes. What causes this line of volcanoes running parallel to the coastline along the northwest coast of North America?
Chris Mueller
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Why are the Great Lakes not considered a sea?
From me looking at maps, excluding the Caspian sea and the Great Lakes, I see these in common for seas and lakes:
Seas
Most are saltwater
Connected to the rest of the ocean via either an isthmus, strait, river, or
gulf
Bigger and deeper than…
Caters
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18
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What temperature do small meteorites have on impact
A question which has haunted me for years. What temperature do small meteorites (which don't evaporate on impact) have if you find them immediately after they hit the surface. I understand that the outer parts are heated by atmospheric friction, but…
tobias47n9e
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When can taste be used to help identify rocks?
Taste can be used to distinguish halite (ordinary salt) from sylvite (which has some bitterness) and siltstone from mudstone (the latter has a creamy texture while the grains of the former can be felt). Are there other uses of taste for…
user26
18
votes
3 answers
Is there any evidence for higher air pressures in the geological past?
I was curious about how the Earth's overall air pressure has varied over time, and tried to take a look around the internet. However, Google pops up a lot of sites with questionable science proposing that the air pressure was much higher in the…
kingledion
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What causes the Earth to have magnetic poles?
A compass can tell me the directions of the Earth's North and South poles? What is it about the Earth that produces this "polarity" such that a compass can pick it up?
The first thing that jumped into my head was the Earth's rotation, but if that…
Kenshin
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17
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If 75% of radioactive material remains, how many half-lives have elapsed?
Radioactive element A radioactively decays into material B. If 75% of A and 25% of B are present, how many half-lives of material A have elapsed?
I was recently taught that the correct answer is "one half of a half-life has elapsed". However, due to…
Timtech
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How accurate are climate proxies in giving us a clear picture of global average temperatures throughout Earth history?
Since reliable modern records of climate only began in the 1880s, proxies provide a means for scientists to determine climatic patterns before record-keeping began, though it appears that the the distribution of proxy records for global average…
blunders
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17
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Why One Side of Mountain Range is Lush
I'm new to this site and certainly not someone with any real background in atmospheric science, so please forgive me if this question is a little stupid.
I recall learning in High School about mountain ranges frequently being dry on one side and…
user153582
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Is global warming being moderated by latent heat of melting polar ice?
I've only had a secondary education in physics, so bear with me, but with the greenhouse effect and all, wouldn't we be much hotter already if the ice melt-rate wasn't increasing, since more (heat) energy goes toward changing state, rather than…
Shane
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Why does the so called "tornado alley" exist?
75% of the world's tornadoes occur in the USA, and within the USA these tornadoes are most likely to occur in particular regions of the country, such as the well known "tornado alley". The diagram below shows tornado activity in various parts of…
Kenshin
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