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20k 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 ...
30k views

Impossible or improbable? Hurricane crossing the equator

No known hurricane has ever crossed the equator. Hurricanes require the Coriolis force to develop and generally form at least 5° away from the equator since the Coriolis force is zero there. Are ...
32k views

What place on Earth is closest to the Sun?

What is the location on Earth that is closest to the Sun? I've seen this question asked many times, and answered in varied and contradictory ways: The most common answer is “the summit of Chimborazo ...
43k views

Are there any saltwater rivers on Earth?

I'm curious if there are any saltwater rivers on Earth. These would presumably arise if a saltwater lake had a river outlet to the ocean. However, all the saltwater lakes I looked at (Caspian Sea, ...
410k views

Why does lightning strike from the ground-up?

The enlightening image below is of a lightning strike slowed down at 10,000 frames per second. It can be seen that the most intense flash produced from the lightening occurs in the direction from ...
45k 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 ...
5k views

What started the US Dust Bowl of the 1930s, and could it happen again?

Most of us know about the Dust Bowl: the huge storms of dirt and dust that swept across America in the 1930's. But what I'm wondering is... What actually triggered the start of the Dust Bowl? Is it ...
6k views

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 ...
31k views

Why is the pond in my backyard not frozen when it is -15 °C (5 °F) outside?

I am in O'Fallon, Missouri and today it is -15 °C (5 °F) outside. I was taught water freezes at 0 °C (32 °F). I could understand if it was exactly 0 °C (32 °F) that the water might not be turning to ...
13k views

How do 'greenhouse gases' let heat in, but not let it out?

That honestly doesn't make any sense to me. How could heat pass through a gas one way but not the other? Its not like our upper atmostphere has a bunch of doors that can only open one way. To me, that ...
14k views

Why do snowflakes form into hexagonal structures?

Snowflakes are known to form into pretty hexagonal structures. The image below shows a variety of such structures that are possible (although by all means not an exhaustive list): What is the ...
99k 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

(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 ...
6k 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 ...
8k views

Are there any uncharted waters left on earth?

While reading about the ghost ship Jiang Seng I noticed that Wikipedia claimed it was drifting in uncharted waters in the Gulf of Carpentaria. I tried to find a primary source referencing uncharted ...
8k views

How it's possible to measure temperature 2000 years ago with such precision?

I saw this graph about the global temperature, it goes back for 2000 years. How is it possible to measure temperature 2000 years back with such a precision of like ~0.1 C? The image from Reddit post I ...
12k views

CO₂ level is high enough that it reduces cognitive ability. Isn't that a reason to worry?

I think the level of carbon dioxide in the air is high enough to reduce the intelligence of humans. This has nothing to do with climate change. Except that both mean we should reduce CO₂. I never ...
41k views

What would be the temperature of earth if there was no atmosphere?

I do know that the atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect),and reducing temperature extremes between ...
9k views

Is the sea level rise unusual?

I'm discussing climate change with a friend who is a climate change denier, basically the argument is that looking at this graph, is not clear that something unusual is going on, so the sea level rise ...
20k views

How is the mass of the Earth determined?

According to textbook knowledge, the mass of the Earth is about $6 × 10^{24}\,\mathrm{kg}$. How is this number determined when one cannot just weight the Earth using regular scales?
929 views

Why do the Siberian methane craters have smooth vertical walls?

I expect most of you have heard of this by now. All the news is about whether or not they were formed by the release of methane, but it is also mysterious to me why this crater has jagged edges but ...
65k views

What does a mm of rain mean?

Lots of people have explained it over many sites but I still can not confidently say that I know what it means when they say Hong Kong experienced 3mm of rainfall last Friday. Does it mean that 3mm ...
33k 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 ...
10k views

Is climate change a vicious circle?

My question refers to the current process of climate change. CO2 is rising, which leads to the greenhouse effect, which raises temperatures. This leads to more wildfires, which reduces number of trees,...
3k views

How do we know the asteroids formed at the same time as earth?

In continuation of the question Why is Earth's age given by dating meteorites rather than its own rocks?, what evidence do we have that the asteroids indeed formed at the same time as earth? Is there ...
905 views

Similarities between grand circulation solvers and mantle convection solvers

My impression is that both ocean grand circulation models (e.g. MITgcm), and Mantle Convection models (e.g. CitcomS), both use Navier-Stoke's as the governing equation. What are the other major ...
8k views

Does gravity increase the closer to the core you get?

Or does the mantle and crust above you counteract the increase at one point and it actually decreases?
9k views

Is there any river that does not discharge into larger body of water?

Do you know any example of a river that does not flow into sea or lake? For example, if water rises from the underground spring and forms a river but water vaporises in hot climate before it reaches ...
14k views

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 ...
3k views

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 ...
13k views

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 ...
2k views

How would plate tectonics differ if Earth had no water?

Water plays a crucial role in plate tectonics by easing the brittle and ductile deformation of the Earth's lithosphere. Water lowers the Mohr-Coulomb for brittle fractures. During ductile deformation, ...
123k views

How high must one be for the curvature of the earth to be visible to the eye?

I would like to ask that at what distance from the Earth's surface the curvature of the Earth is visible. What layer of the atmosphere is this? I've noticed that at the height of 9-12 Km (the view ...
6k views

How and why did the oceans form on Earth but not on other planets?

Earth is the only planet in our solar system that has copious amounts of water on it. Where did this water come from and why is there so much water on Earth compared to every other planet in the ...
9k views

Why do felsic materials have lower melting points than mafic?

It is clear from Bowen's reaction series that more felsic minerals have lower melting points than mafic minerals. As far as I know, the same is true of quenched glasses. Felsics have a higher degree ...
10k views

Is it true that earthquakes are not felt in a cave?

I took a tour of a cave in northern California last weekend. The tour guide asked us, "If an earthquake occurred, what would we feel in here?" My answer was, "fear," but she said we would feel ...
4k views

Why does Coriolis determine the rotation direction of a cyclone but not my drain?

It is a common misconception that Coriolis is responsible for the direction the water swirls down a toilet, tub or sink drain. E.g. does a toilet flush the other way in the southern hemisphere? (If ...
1k views

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?
3k views

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 ...
3k views

Is earthquake prediction possible?

After the Tohoku and East Coast quakes, I skimmed over several books discussing the validity of earthquake prediction as a discipline, yet found no significant breakthroughs. What should change in our ...
10k views

Where on Earth is the magnetic field intensity stronger?

Are there places on Earth that have a strong magnetic field other than the magnetic north and south poles? Can living where (rare) earth magnetic ore is abundant provide a mini-magnetoshere?
44k 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 ...
35k views

Why is Earth's outer-core liquid?

The Earth's inner core is solid because despite the enormous temperature in this region, there is also enormous pressure there, which in turn raises the melting point of iron and nickel to a value ...
7k views

How would an icicle “grow” upwards?

The other day a friend of my dad's showed him a picture of an icicle that appeared to be "growing" upwards out of a crack in a sidewalk. There were no roofs, overhangs or vehicles parked near by... It ...
50k views

At what humidity does it start to rain?

As far as I understand it is perfectly valid for air to have 100% humidity. At that point, all water can still exist in form of vapor, non-condensed. Does it immediately start to rain if humidity is >...
2k views

What is the status of the Raymo & Ruddiman idea that Tibet cooled the Earth?

What is the current status of the Raymo & Ruddiman hypothesis that the uplift of the Tibetan Plateau during the Cenozoic cooled the Earth, resulting the current ice age(*)? cf. Raymo, M.E. and W....
4k views

How do weather models work?

We use different weather models all the time, such as the ECMWF and the GFS. These models are simply amazing to me. How do these models work? I know they have to take in various data points - what ...
1k views

Can pyroclastic flows cross water?

While reading the Wikipedia article on pyroclastic flows, I noticed that there's a section called 'Interaction with water'. This piqued my interest, as I was under the impression that lava generally ...