# All Questions

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### What is the origin of the Montmartre mountain in Paris?

I have always wondered what is the origin of Montmartre mountain in Paris. What surprises me is that the whole area seems quite flat, and yet there's a very steep hill in the middle. How has that ...
797 views

### What data does a skilled meteorologist look at to predict thunderstorms?

An uneducated layman like me would just look at CAPE numbers and make rough guesses on possible thunderstorms. In a related but non-duplicate question, vertical wind shear is discussed. If we are ...
2k views

### What causes intra-plate faults, such as the New Madrid fault?

There's been news (some recently) about the New Madrid fault and other active intra-plate faults. For those living in the midwest of the United States, it's been a bit of a shock to learn they have ...
266 views

### What can we learn by studying lunar atmospheric tides?

Lunar atmospheric tides are likely insignificant for weather, although Guoqing (2005) asserts that The lunar revolution around the earth strongly influences the atmospheric circulation. They don't ...
663 views

### How are Mauna Loa $\ce{CO2}$ monthly trends computed?

The problem I am trying to figure out how $\ce{CO2}$ concentration trends are computed in the data provided by the Earth Systems Research Laboratory Mauna Loa Observatory. The data contains monthly ...
17k views

### Why doesn't the 71% water of the earth dry or evaporate?

Perhaps a simple question, we know 71% of the earth's surface contains water as oceans. If Earth's age is 4.543 billion years, then I guess it should be decreased with drying or should have been dried ...
7k views

### Why clouds are not moving in NASA's video of the Moon passing in front of the Earth?

I recently saw a short video from NASA. It shows the moon passing by the Earth as it rotates. NASA link: From a Million Miles Away, NASA Camera Shows Moon Crossing Face of Earth. The video itself ...
7k views

### Why do trees break at the same wind speed?

Several people have independently mentioned to me that all trees break at the same wind speed. This phenomenon is independent of type and size of the tree. Supposedly, Galileo already had described ...
5k views

### Do fossil fuels insulate the crust from the Earth's interior?

I was doing a project for my English class, and I came upon the article Energy conservation in the earth's crust and climate change. I can't view the full text of the article, but the abstract piqued ...
27k views

### 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, ...
5k views

### Is it true that a butterfly flapping its wings can result in a tornado in a distant location?

I have heard that extreme storm events can be caused simply by a butterfly flapping its wings somewhere in a distant location. Is it true that such a small disturbance in the air in one location can ...
4k views

### Are metals and other elements in every continent?

I originally thought that you can only find certain things like iron, copper, and other things in certain places in the world and deep in mines but I saw in a few YouTube videos that you can find iron ...
7k views

### Was Judea as desertified 2000 years ago as it is now?

The ancient fortress of Masada is currently so dry and forbidding that is hard to imagine anyone living there. Was the climate in the surrounding area more wet 2000 years ago, or was it as much a ...
18k views

### What was the first rock in the rock cycle?

I am an undergraduate student but I am a tutor at a High School, and one student asked me. Attempting to explain the rock cycle "if one rock turns into the other then which came first" my gut is ...
797 views

### How do we know that we are NOT in an “Ice Age?”

Historically, the earth has had five "Ice Ages" Each of them lasted millions, tens of millions, or hundreds of millions of years. The last ice age reportedly ended perhaps 10,000 years ago. That ...
6k views

### Debunking scientific paper “Has global warming already arrived?”

I read the IPCC reports, I know global warming is happening and is man-made. But as any skeptic should do periodically, I went to a few climate deniers websites and stumbled upon this peer-reviewed ...
3k views

### Can the previous weather be computed from the current situation?

If one applies today's state-of-the-art weather forecast computations "backwards", i.e. computing how the systems was X days before the current situation based on knowledge of today's situation, at ...
1k views

### What is this “crystal ball” located at a meteorological station?

I found what looks like a "crystal ball" in a meteorological station in the Vlădeasa mountains (Romania). What is its purpose?
8k views

### Paleontology science fair ideas?

My daughter, age 8, wants to do her science fair project in paleontology. For the fair, we need to come up with a question that can lead to a hypothesis, then apply the scientific method to test this ...
6k views

### Do volcanos really create fertile soil?

I'm developing an ecology for a portion of my world that's geologically active and I remembered hearing that volcanic ash in soil makes it more fertile to agriculture. After extensive googling I've ...
1k views

### Why is there no middle ground between tornadoes and hurricanes?

A tornado has an effective area of destruction about the size of a city block. A hurricane spans several hundred kilometers. However, there doesn't seem to be a continuum between the two. Why are ...
841 views

### How does one measure what causes earthquakes?

I know that they occur when energy that was previously stored is released in seismic waves. But how is the energy stored in the earth in the first place, and what can trigger the release of such ...
44k views

### How do seismologists locate the epicenter and focus of an earthquake?

I know the focus of an earthquake is where the earthquake originated from, but what I could never figure out is, how to scientists find out where exactly the focus (and epicenter) are located?
279 views

### Will tropical cyclones form and be sustained in areas they previously were not due to global climate change?

With global climate change, is it possible that tropical cyclones (as seen in the Atlantic basin for example) are going to form and be sustained in regions where they previously did not, for example ...
334 views

### Is there any consensus of what caused the Lusi Mud Volcano eruptions in Indonesia?

In May, 2006, the Lusi Mud Volcano in eastern Java, Indonesia came to life, smothering much of the surrounding land in mud. According to the article Indonesia's Infamous Mud Volcano Could Outlive ...
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?
966 views

### Current consensus on the Messinian Salinity Crisis

In 1973, Hsü et al. explained the findings of a large evaporite deposit during the Messinian (Latest Miocene stage, ca. 6Ma) in the Mediterranean by a basin-wide desiccation event. It has been ...
432 views

### To what accuracy and precision do we know the volume of the Earth?

Satellites such as GOCE and GRACE measure the geoid with unprecedented accuracy. Altimeters can determine local surface elevation with millimetre-precision. This makes me wonder: to what precision ...
3k views

### Why do more tornadoes happen late in the day?

According to the graph below, which appears to be sourced from the US National Oceanic and Atmospheric Administration, more tornadoes happen late in the day - why is this?
1k views

### What was the Amazon like during Green Sahara?

It is said that the Amazon rainforest receives up to half of its nutrients via mineral dust from the Sahara desert. But a few thousand years ago, the Sahara desert was much more fertile, having a ...
1k views

### What was the ocean circulation like during the time of Pangaea?

So Enderton and Marshall (2009) wrote an interesting paper on the ocean circulation of various aquaplanets covered with certain terrain: e.g. an aquaplanet with a small ridge of land that ranged from ...
8k views

### Lanes of flat ocean surface in coastal waters

When the ocean is still, i.e. there aren't waves that disturb the surface, you often see "lanes" of water that seem flat as opposed to areas where the wind causes ripples. What causes this?
17k views

### Where can I get archived hourly temperature data?

I am looking for historical hourly temperature data from many cities in the US what other data sources are there except wunderground? UPDATE: I will use the data to compare stations from the same ...
301 views

### 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 ...
5k views

### Does rain (temporarily) deplete the surrounding atmosphere of carbon dioxide?

CO2 in the air dissolves into rain water, making them slightly acidic. Is that enough to deplete the surrounding air out of CO2? If yes, how fast does this occur? Is it only with the first drops of ...
16k views

### What caused the bend in the Emperor/Hawaii chain of islands, 45 million years ago?

What caused the bend in the Emperor/Hawaii chain of islands, 45 million years ago? Has there been any updates to this mystery I am unaware of? Are there any new theories that could potentially ...
1k views

### What fraction of dry land is below sea level?

Someone just asked me if it would be practical to counter the rise of sea level by pumping water into storage on land. It struck me that if there is enough land below sea level, this would require ...
2k views

### Why does Earth have abundant oxygen in the atmosphere?

Because of photosynthesis, obviously. But then it's not actually that obvious after all, because photosynthesis is mostly balanced by respiration. We can summarise the processes of photosynthesis ...
370 views

### What are the physical upper bounds on the magnitude of an earthquake?

Given what we know about the physical mechanisms underlying earthquakes, what do the theoretical upper bounds on the magnitude of an earthquake look like? What physical phenomena impose those upper ...
4k views

### Why aren't seismic stations installed very deep underground so as to pre-warn from earthquakes?

The velocity of p-waves emanating from earthquakes is in the range of 5-8 km/s (link)--let's assume it is 5 km/s. The earthquake depth is up to hundreds of kms deep underground (link)--let's assume it ...
6k views

### How to quickly or easily prove the world is spherical?

A relative of mine has recently introduced me to the modern flat earth theory, which she believes in. Setting aside for the moment that it is ridiculous, and that sending up some balloons with cameras ...
565 views

### Is there any simple way of using the Coriolis effect to determine what hemisphere you are in?

I have heard from many people that sinks do not empty in a particular pattern depending on what hemisphere you are in, but I have also heard from people who adamant that a sink of water would empty ...
5k views

### What would be the first thing which will render the Earth uninhabitable?

There are quite a few things which can make an otherwise habitable planet uninhabitable, and some of these will eventually happen, sooner or later: engulfed by its star when it becomes a red giant ...
9k views

### What does it mean for waves to “feel” the bottom?

While typically waves are said to "feel" the bottom when the depth of the water is less than half the wavelength, what does it mean for the waves to "feel"? Furthermore, why does this happen at the ...
2k views

### Why deep ocean didn't freeze during snowball Earth?

I know that at least twice in its history Earth was totally frozen. I also know that the last time it happened there were already life on Earth, and it survived. In deep water, under the ice, which ...
4k views

### Do dams reduce the flow of river downstream?

There is a conflict between Egypt and Ethiopia, because the latter wants to build a dam on the Nile river. Citing this article: [Egypt] fears the Nile dam will reduce its share of the river and ...
6k views

### Where is the calmest place on Earth?

I have done some research online, and I've found out that Antarctica has the calmest winds (lowest maximum wind speed) recorded on Earth. However, it is uninhabitable for human life. Other very calm ...
15k views

### What would be the effect of bringing seawater pipes to the Sahara desert?

This is a childhood dream. What would happen if pipes were installed (similar in principle to the Great Man-Made River, but for seawater) to continuously pump seawater into the Sahara desert. Let'...