# All Questions

4,904 questions
Filter by
Sorted by
Tagged with
172 views

### Is the majority of Earth not unique?

Realize that comparing planets is hard, but is Earth really that unique? More to the point, if everything say 20-km below sea-level up into the exosphere disappeared (and the moon too) - what would ...
5k views

### Does Earth's air leak into space over time?

From my current understanding, Earth's atmosphere and air are held by the balance of two forces: 1. Earth's gravity and 2. Air pressure from air out to space. Is my understanding correct? So, do ...
1k views

### How do we know graptolites were pelagic?

How do we know that graptolites were pelagic, and not benthic, creatures? I understand it has something to do with their being found in black shale, but I'm not sure why that is particularly relevant.
42k 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?
2k views

### Why does El Niño only exist in the Pacific Ocean and not the Atlantic/Indian Oceans?

El Niño is associated with the weakening of the ‘normal’ pressure/temperature gradients between the western and eastern Pacific Oceans. My question is this: why does it only exist in the Pacific ...
246 views

### Recharge a dry aquifer?

Aquifers have a natural recharge rate. However, some aquifers rely on fossil water for their primary (or even sole) water supply. When water in a well is pulled from these aquifers faster than they ...
13k views

### What determines a mineral's hardness?

Mohs Hardness Scale is basically a measurement of the hardness of a material, or more specific, a rock or mineral. But I have never been able to figure out why some minerals are harder than others.
180 views

### Why does the rising of high clouds due to climate change impart positive radiative feedback on radiative forcing?

As seen in the figure below. The larger the temperature difference between surface and cloud, the more positive the radiative forcing is from the cloud. So as the cloud moves up, it supposedly ...
176 views

### Are clouds significantly easier to simulate in weather models than climate models?

Cloud forcing is still one of the major uncertainties of radiative forcing in climate modeling because there are so many uncertainties in it (and parametrizations). But also because the timescale of ...
691 views

### How do scientists determine the absolute or 'chronometric' date of fossils?

Absolute dating is the process of determining an approximate computed age of something like a fossil. How does that work?
1k views

### Why are most cirrus clouds present over the equator and over tropical continents?

As quoted from the AR5 IPCC report (chapter 7) here. Most high cloud (mainly cirrus and deep cumulus outflows) occurs near the equator and over tropical continents, but can also be seen in ...
329 views

### How does the lapse rate in clouds compare with the lapse rate of air?

So moisture decreases the temperature lapse rate (relative to the dry adiabat). My question is this: does a cloud decrease the lapse rate at the same rate as 100% humidity would decrease it? Or would ...
2k views

### What would a replacement for SEGY look like?

I have been having a miserable time this week reading SEGY files. This is data from the largest seismic acquisition company in the world whose client is the 7th largest oil company in the world. So if ...
3k views

### Formation of flint & chert in limestones/chalk

Chert and flint are commonly found in chalky deposits (and have obvious importance in human history as tools). What are the processes of diagenesis of these silica-rich nodules in otherwise silica-...
2k views

### Exhumation of blueschist

Blueschist has a mineral assemblage such that it must have formed at high pressures and low temperatures. It must therefore form in subducting slabs (and I believe this correlates with the locations ...
4k views

### How long to melt all the polar ice?

The answers to this question say that the sea level will rise 66m if all the polar ice, etc, melts. How long will this take? Transporting incredible amounts of heat energy to the poles and injecting ...
17k views

### Is Mount Everest currently becoming taller or shorter every year?

Is Mount Everest becoming taller or shorter every year? By how much? I would like an explanation in terms of tectonic plate movement if possible. Source: IamKatieHoffman.com
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 ...
84 views

### Why does volcanic dust pose such a hazard to air travel?

What properties does volcanic ash have that make it a hazard to aircraft jet engines which are not posed by other sources of atmospheric dust, such as Saharan dust? Is it merely a question of ...
5k views

### How can I tell if a rock is really petrified wood?

I found a rock in the Mojave desert and it resembles a tree branch including what appears to be wood grain. Is there some test or observation that can be done at home to conclusively answer my ...
2k views

### Would the Earth function the same spinning the other way?

Right, I saw a question about why the Earth spins counter clockwise, and it reminded me of something I would like to know the answer to. I watched a episode of Futurama. In this episode the Earth ...
11k views

### Why is the troposphere 8km higher at the equator than the poles?

Fundamentals of atmospheric modeling show that the height of the tropopause depends on the location, notably the latitude, and that the troposphere is roughly 8km higher at the equator than the poles ...
5k views

### Are there more earthquakes near the equator or poles?

When comparing the average distance of the all known earthquake epicenters to the nearest pole, is the longitudinal distance to the equator or the poles the smallest of the two? Please note that any ...
1k views

### Why is earth's axis tilted?

Why is the axis of earth tilted? It can't possibly be that the Northern hemisphere is larger causing it to be pulled toward the sun, because then it would always be summer in the N hemisphere and ...
28k views

### Why does the earth spin clockwise?

Why does earth rotate in a clockwise direction? Did a large meteor collide with earth causing earth to rotate? If that is what happened, could another, larger meteor cause earth to reverse its ...
234 views

### What is the furthest observable phenomenon from Earth that is Earth Science?

Guessing that the Earth's magnetic field is the furthest observable Earth Science related phenomenon from Earth itself, though not completely sure.
212 views

### How can the 'abiogenic oil' hypothesis be disproven?

We do know that complex hydrocarbons (e.g., tholins) exist in the outer Solar System. Some geologists maintain that at least some oil on Earth is of non-biological origin. The mainstream, though, ...
296 views

### Has the number of natural disasters per year increased significantly in the years since human-caused climate change started?

Human-caused global warming has had an increasingly significant effect on the earth since the industrial era began. Since the beginning of the industrial era, has there been a significant increase in ...
2k views

### What are the domains of Earth Science?

Increasingly confused by all the "spheres" and agreed relationships between them. As a result, I am looking for a singular answer that clearly states at the very least what the top-level and secondary ...
1k views

### A good book or source for climate science and meteorology basics?

I have a mainly a hydro-geological and geo-statistical background, I would like to have a basic introduction to meteorological, climatic processes and modelling techniques related to these fields. Any ...
204 views

### Earth Science Search Engine

After scirus is closed, which search engine do you all use? I know of Arxiv, and ADS, which only partially overlaps with Earth Science related issues. Any other recommendations would be appreciated.
59 views

### Lab procedure for analyzing/assessing the presence of semi-volatile solids

I'm looking for a lab experiment design that shows how to measure the presence of semi-volatile solids in water (and not sludge or soil or solids). All I have found so far are chromotography/mass ...
68 views

### Is global warming occuring only because of humans? [duplicate]

I learned that human activities produce gases that deplete the ozone layer, and create the greenhouse layer, which increases the world's temperature. (And seems real , now in Thailand it's 35 degree ...
123 views

### Measurement of groundwater levels

There are numerous measurement systems available for measuring groundwater levels (head / stage). What period of time should measurements be collected in order to draw solid conclusions about the ...
6k views

### How much will sea level rise if all the polar ice melts?

There are many movies about global warming, which say that melting of all polar ice would cause the whole world to suffer a huge flood. According my research (teachers, TV, Internet) people hold one ...
613 views

### Why do those glaciers form on the lee side of the mountains?

In the Scandinavian mountains, there is a strong effect of orographic precipitation. The west receives far more precipitation than the east. This difference can be a factor 5 or more in some places. ...
788 views

### What factors affect the size of rain shadows?

Rain shadows are dry areas on the lee side of mountains. Due to humid air condensing and precipitating as they are lifted up and over the mountains, they lose moisture by the time they reach the lee ...
396 views

### Bifurcation Scenarios in the Atmosphere

I read that the mathematical definition of bifurcation is that, at a critical value of a parameter that governs the dynamical system, the system changes to a topologically different system than the ...
123 views

### What is the concentration of silver in tap or freshwater in the United kingdom

Can anyone tell me the concentration of silver in uncontaminated water ways, or treated tap water in the united kingdom? sources would be desirable too
485 views

### Are mantle plumes distributed around the core randomly or in a known pattern?

Background: The theory of mantle plumes is useful (although controversial) in explaining the occurrence of intra-plate volcanoes. The website here suggests that "hotspots" exist in fixed locations ...
226 views

### Do normal modes of oscillation cause permanent deformation?

It is known that when a large earthquake occurs, say $M \ge 9.0$, The surface waves travel around Earth over and over, "ringing the surface like a bell". The GIF below is an example (Image Source): ...
364k 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 ...
3k views

### 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 ...
5k 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 ...
2k views

### Is Earth an organism?

According to Wikipedia, "all known types of organism are capable of some degree of response to stimuli, reproduction, growth and development and self-regulation via homeostasis." Further, watching a ...
135 views

### How far from basalt bedrock can magnetometic survey find archaeological features?

Magnetometry is used to find archaeological features such as stone walls or ancient hearth. But it usually cannot be used for archaeological prospection in areas where the bedrock is strongly magnetic....
356 views

### What is the current theory about the formation of Tibet?

Although I basically understand, that how the Himalayas formed, it has always confused me how did the vast high Tibetian Plateau came into existence behind it? And what would be its future, is it ...
33k views

### Why is Earth's inner core made of an iron-nickel alloy?

This question has puzzled me for a while. I know that earth's mantle is made of different minerals, metals and rocks etc. and that has always made complete sense to me. But why is the inner core made ...
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 ...