# All Questions

574 questions
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### How can we determine the size and composition of Earth's inner core?

From Wikipedia: Earth's inner core is Earth's innermost part and is a primarily solid ball with a radius of about 1,220 km (760 mi). (This is about 70% of the Moon's radius.) It is believed to consist ...
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### What factors determine the number of Hadley cells for a planet?

We know (think?) that Earth has three Hadley cells per hemisphere, but from observing gas giants such as Jupiter, we see that they have many more cells. According to a link from a comment in this ...
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### Why are there no hurricanes in the southern Atlantic basin?

We see tropical cyclones (going by different names e.g. hurricane, typhoon, cyclone) all over the tropics, but it seems that there are never any storms in the southern Atlantic. See this map of ...
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### What are the high field strength and large ion lithophile (HFS or HFSE & LIL or LILE) elements?

There are two groups of elements that are frequently mentioned when discussing incompatible trace elements. They are the high field strength elements (HFS or HFSE) and the large ion lithophile ...
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### What are the causes of the supercontinent cycle?

Throughout geologic history, Earth's continents have broken apart and come together to form supercontinents multiple times, in a somewhat regular period, known as the supercontinent cycle. The length ...
30k views

### How many trees would I have to plant to solve Global Warming?

According to Nasa, causes of the Earth's greenhouse effect include water vapor, carbon dioxide, methane, nitrous oxide, and CFCs. Carbon dioxide gets the most press, and NASA's page says: Carbon ...
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### How much oil is created each year?

We all know that oil is an essentially nonrenewable resource over human time scales. However, I am currently working on an activity for high schoolers that teaches them to predict how long humans can ...
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### How does anthropogenic heating affect global warming?

Anthropogenic-sourced greenhouse gases are commonly cited as the main source for human-caused climate change. However, something that I never see discussed is the actual heat produced by human ...
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### Equinoxes and solstices: start of the season or mid-season?

In the United States, the upcoming autumnal equinox is marked on most calendars as the "first day of autumn." Similarly the solstices are commonly called the "first day of summer" and "first day of ...
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### Could earth's core lose its heat?

Will all of the drilling and digging to use the earth's natural heat as geothermal energy be affecting Earth's core, causing it to cool down? If so, would it result in an ice age? If not, how does it ...
5k views

### Where does wind come from?

Wind is (according to Wikipedia) the flow of gases on a large scale.On the surface of the Earth, wind consists of the bulk movement of air. What forces would cause such a mass movement of air?
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### In what geological situations can I find gold?

I've heard that gold ore is often associated with quartz veins. What geological processes enable gold particles to naturally cluster together like this? What characteristics/properties should I look ...
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### Why is Earth's age given by dating meteorites rather than its own rocks?

Reading a course on Precambrian, I read that: Earth Age (around 4.5 billion years) is dated thanks to the meteorites hitting Earth during its formation rather than the inner materials composing the ...
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### Can mining trigger earthquakes?

Are earthquakes more common in mining regions than they would otherwise be? e.g. is the frequency of earthquakes in those regions different when mining is occurring than when it is not? I am ...
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### At what point does plate tectonics stop?

As the core and mantle of the earth cools, it will reach a point where new crust cannot be produced. How can this point be calculated? If we can, has anyone done such calculations? Thanks!
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### Do ringwoodite minerals point to an “ocean's worth” of water, or a true subterranean ocean?

Appears that the answer is that it is highly likely that the water that the ringwoodite minerals point to is an "ocean's worth" of water, not a true subterranean ocean. Do ringwoodite minerals ...
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### What do continents “lay” on?

It's a simple question.. What do continents "lay" on? Do they float on water? or are they huge bodies that "emerge" from the sea floor/bed? are they connected to the bottom of the oceans? Hope the ...
941 views

### How to compute du/dx and dv/dy in moisture flux convergence?

I have $u$-wind, $v$-wind and specific humidity. I would like to compute moisture flux convergence at a grid point. So I need to compute the value of $q(\frac{du}{dx} + \frac{dv}{dy})$ My question is ...
456 views

### Why is uranium only in the crust, really?

As I know, uranium is currently thought that it is mainly in the crust and not in the core or in the mantle. The reason for that it is a siderophile element which means it won't be solved in molten ...
19k views

### How can a storm drop 40 inches (1 metre) of rain?

Hurricane Harvey dumped more that 20 inches (500 mm) of rain over a large region, with 40+ (>1000 mm) in some spots... and much more expected. How is that possible? Does the atmosphere really hold ...
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### (How long) would Earth's atmosphere last without a global magnetic field?

The Earth's magnetic field provides an important protection against the solar wind (for example, see Wikipedia on Earth's magnetic field and references therein). Mars may have lost its atmosphere ...
93k views

### Are Richter-magnitude 10 earthquakes possible?

The largest earthquake since 1900 according to the United States Geological Survey (USGS) was Richter-9.5 magnitude quake in Chile in 1960. Are magnitude 10 earthquakes possible? If so, what is the ...
5k views

### Farthest point from the center of the Earth

At first glance, this seems like such a simple question of "What's the highest point on Earth". However, I also know that the Earth isn't perfectly round. So that "highest point" may be in a ...
34k views

### Is it possible for rivers to freeze completely and stop flowing?

Is it possible for rivers to freeze completely in the winter and stop flowing? Are there known examples of this? If yes, how large can these rivers be and where does the water go? There are several ...
5k views

### Why does the Hadley cell descend at 30 degrees?

George Hadley's initial model of the Hadley cell described air as being heated at the equator, ascending, and then moving aloft pole-wards where it would cool and descend. Meanwhile surface air would ...
29k views

### Why is Earth's inner core solid?

I have never understood why earth's inner core is solid. Considering that the inner core is made of an iron-nickel alloy (melting point around 1350 C to 1600 C) and the temperature of the inner core ...
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### What percent of the Earth's core is uranium?

What percent of the Earth's core is uranium? And how much of the heat at the core is from radioactive decay rather than other forces?
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### Resources for learning the technical parts of atmospheric modeling

I'm a computer/atmospheric science undergrad and I'm trying to get into atmospheric modeling. Any recommendations for resources to get going or to learn about approaches? I can handle fairly technical ...
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### If the Earth were a smooth spheroid, how deep would the ocean be?

At the moment there are deep seas and high mountains. But imagine that the land elevation of the Earth is equal everywhere. How deep would the ocean be in that case?
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### Why is relative sea-level falling in Hudson Bay?

Why is the sea level in Hudson Bay decreasing so much? Hudson Bay is pretty far up north, much closer to glaciers. Would it make sense for it to recede at this level with sources of fresh water ...
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### How long until Earth's core solidifies?

How much longer does Earth have until the core turns solid? Does global warming change these estimates at all?
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### Why air do not suffer density stratification of its gaseous components?

The different gases that make up the air have different densities. So, naively, one would expect the heavier gasses to pool in the lower atmosphere and the light ones at the top. I asked myself this ...
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### How to calculate specific humidity with relative humidity, temperature, and pressure

I know there is this question already How do I convert Relative Humidity into specific humidity but I don't have ρws = density of water vapor (kg/m3) and ρ = density of the moist or humid air (kg/m3)....
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### Safest spots when an asteroid hits? [closed]

I am breaking this question and no longer making an effort in refining it with the exception of adding an associated link with the scenarios. I always wondered if a devastating asteroid was ...
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### How much of the current global warming is due to human influence?

Approximately what proportion of the global warming seen over the the last century is attributed to anthropogenic sources?
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### How good were climate models of the 1990s at predicting the global temperature trends of the 2000s/2010s?

Was there a significant bias between the ensemble of climate models and the long-term temperature trends? What about spatial patterns?
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### What are rare earths and why do they cluster near alkaline magmatism?

'Rare earths' play a vital role in the modern economy, and they are becoming more of a point of focus in geopolitical realms. What are 'rare earths' and why do they appear to cluster in association ...
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### Can large (and wet) storms really trigger large magnitude Earthquakes?

At the 2011 AGU Fall meeting, this poster claimed that the water erosion from Taiwan's wettest storms could prematurely trigger large magnitude earthquakes , $M \ge 6.0$. If this was true, this ...
719 views

### Are there secondary causes of sea level change?

Aside from the fraction of water stored as ice on land and temperature of the water, are there other factors that change sea level, and if so what are is the magnitudes of the these changes? For ...
12k views

### What is the difference between eluvium and alluvium?

I was reading about kimberlite on Wikipedia and it mentioned eluvium. I've heard of alluvium, alluvial fans, alluvial deposits, etc. However, when I looked up eluvium, it sounded exactly like alluvium....
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### What are these lake-like blue patches in the desert, visible in satellite image?

I found some blue patches in the Arabian desert in Google Earth. It looks like as if they were lakes with sand dunes rising out of the water. But there isn't water in the desert, at least not this ...
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### Why does air subside in the Eye - the lowest pressure area of a tropical cyclone?

A low pressure area is associated with rising air while a high pressure area is associated with subsiding air. The best explanation I could come up with is either the cyclone is an exception or the ...
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### How to read a NetCDF4 file in Matlab?

I have downloaded the sea surface temperature data from the Ocean Color website, the file is in NetCDF format and contains no of geophysical_data variables like sst,...
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### Why is there a seasonal cycle to the amount of CO2 in the atmosphere?

I'm doing some homework on the increase of $\mathrm{CO}_2$ in the atmosphere. On one of the graphs it shows the amount of $\mathrm{CO}_2$ peaks in May and has a low in November. Why is this? Shouldn't ...
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### How will cloud feedback effects on the climate change as the result of global warming?

So global warming will increase the tropospheric temperatures, which, in turn, would make the clouds higher than they otherwise would be. And higher clouds (especially cirrus clouds) tend to trap in ...