Questions tagged [geophysics]

Geophysics is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment.

Filter by
Sorted by
Tagged with
6
votes
2answers
257 views

Why doesn't the Earth's outer core dissolve into the mantle?

It is well accepted that the outer core is made out of liquid iron and nickel, and as everything else it should tend to reach chemical equilibrium with its surrounding. In particular, I would expect ...
6
votes
2answers
3k views

How do seismic charges help to investigate the subsurface?

In the film Kong: Skull Island, scientists investigate an island's structure by dropping explosive charges from helicopters: Source: YouTube trailer In reality, geophysicists do something similar ...
6
votes
1answer
191 views

Why is ground water rising on these forest rings?

I am seeking a physical explanation for this; There is huge amount of such a Forest rings in Earth; (Link to Google Maps to one ~400 m Ring) They range in diameter from 30 metres to 2 kilometres, ...
5
votes
1answer
627 views

Is there evidence to delineate where a southern extension of the East African Rift 'plate boundary' is developing?

The East African Rift system is described by James Wood and Alex Guth of Michigan Technological University in the Geology.com web-article East Africa's Great Rift Valley: A Complex Rift System as ...
20
votes
3answers
2k views

Can the overuse of geothermal energy become an environmental concern? [duplicate]

At what power output would we be using so much geothermal energy that we cool the core enough to endanger the Earth's magnetic field and have to stop using it? Is this a conceivable concern for a ...
17
votes
2answers
371 views

What geophysical events can (temporarily) increase the Earth's rate of rotation?

My understanding is that the dominant factor behind the slowing of the Earth's rotation (i.e. the lengthening of the day) is tidal friction induced by the Moon's gravity. As seen on the graph below, ...
16
votes
0answers
204 views

How much heat is transported from the interior to the surface in the form of hydration enthalpy?

Heat is transferred from the interior to the surface through several methods. One is simply the conduction of sensible heat through the crust - I would guess this accounts for most of it. But some is ...
16
votes
2answers
344 views

Did the impact event that caused the Chicxulub-Crater definitively and single-handedly cause the Cretaceous-Paleogene extinction?

Opinions abound on the web. What is the state of the current science regarding this theory and what is the best evidence? Is the theory gaining or losing traction? If it's losing what's the best of ...
16
votes
2answers
1k views

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 ...
14
votes
3answers
1k views

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 ...
12
votes
4answers
1k views

What do the derivative or the integral of amplitude of a seismogram mean?

I'm doing a project in which I'm analyzing earthquake seismogram waves. I used a program to graph the exact amplitudes and how they changed over the course of a single earthquake. For the project I ...
12
votes
4answers
2k views

When will the Final Ice Age happen?

As the Sun's luminosity slowly rises, the Earth's surface temperature will climb. Will Earth ever be too warm to have any more glacial periods? If so, when will that be? Edit: The existing answer ...
11
votes
2answers
4k views

Is the epicenter always directly above the hypocenter?

All the graphics I've seen showing epicenters with a hypocenter (labeled focus in the graph below) appear to show that epicenters are always directly above their related hypocenters. Is this correct?
8
votes
2answers
2k views

How viscous is the Earth's mantle?

I'm posting here to get some more expert information based on this question. If the Earth were to stop rotating, removing the centrifugal force causing the equatorial bulge, how long would it take ...
8
votes
4answers
3k views

Are the oceans rising or the continents going down? How can we know?

The century old sustained rising of oceans, at a rate of 2-4 mm/y, remains a unexplained phenomenon; there is no correlation with temperature variations, so it is not due to the thermal variation of ...
7
votes
1answer
445 views

What “g” would be needed to keep helium on Earth?

I know that helium is a very light and rare gas on Earth because Earths gravity is not strong enough to keep it. Instead, helium and hydrogen are rising through the atmosphere and escape into outer ...
6
votes
1answer
452 views

How are the ZNE, ZRT and LQT coordinate systems defined?

I'm confused about the direction of Z (upward or downward?), R (outward or toward the source?) and T.
6
votes
1answer
192 views

Why do we measure eustatic sea-level from the center of earth?

Earth is rotating so it has a ellipsoidal shape. The measurement will therefore be different from equator and pole. So why do we measure eustatic sea-level from the center of earth?
5
votes
2answers
350 views

Why did the carboniferous period have so much atmospheric oxygen?

Even if all the carbon dioxide (which makes up less than 1% of the atmosphere) in the air were sequestered by plants, would the atmosphere not remain about 21% oxygen? Why did the carboniferous period ...
5
votes
3answers
2k views

Does the Coriolis Effect affect a wind from East to West?

I'm studying meteorology for a pilot license and there I was taught as a rule of thumb that wind at higher altitudes is approximately turned 30° clockwise to the wind on the surface due to the ...
5
votes
1answer
418 views

What is the tectonic explanation for parallel ridges in the Arctic Ocean?

Looking at a map of the underwater features of the Arctic Ocean reveals three roughly parallel ridges, separated by basins (see image below): Image source The three ridges, as labelled are the Alpha ...
4
votes
2answers
168 views

Thermal expansion of Earth

Matter tends to change its volume in response to changes in temperature--or, hot things tend to be expanded. Is the thermal expansion of Earth significant? That is, is it significant when compared ...
4
votes
2answers
8k views

How can we measure the thickness of the Earth's mantle? [duplicate]

According to Wikipedia the earth's mantle is approximately 2900 km (1,800 miles) thick. How is it possible to achieve such measurements? Obviously we haven't sent anything down that far to check.
3
votes
1answer
181 views

Why doesn't Earth absorb our carbon emissions?

If we look at the carbon cycle, we see that man-made carbon emission only account for a tiny fraction of all $\text{CO}_2$ emissions. However, we see a steady rise in atmospheric $\text{CO}_2$-levels....
2
votes
3answers
2k views

Why is the density of Earth higher at the core

If gravitation decreases as we approach the core and if density is a function of gravity we should expect a void core. Unless the accretion disk was formed starting with the objects of highest mass ...
2
votes
0answers
155 views

Why are all rainbows are not the same? [closed]

How does these rainbows water drops differ? I know it has to do with the size of water drops refracting light. Is there a formula that determines the type of rainbow? Icebow Unlike this questions ...
2
votes
1answer
129 views

Why the “Mission to Earth’s core” proposal suggests using liquid iron instead of lead?

Nature communications article "Mission to Earth's core — a modest proposal", suggests placing a large volume of liquid iron in a crack and let it sink all the way to the Earth's core, carrying along a ...
1
vote
2answers
373 views

What is the highest balloons possible in a chain?

The BU60-1 balloon attained an altitude of 53.0 km (32.9 mi; 173,900 ft). Weather permitting, would a series of climbable balloons in a chain be able to be linked from the ground to that height of ...
1
vote
1answer
68 views

Forest rings shape regularity

In the answer to "Why is ground water rising on these forest rings?" it is written: these rings are too numerous and too regular in shape to be related to either kimberlites or (even more ...
0
votes
3answers
549 views

What are some good resources to learn about geophysics? [closed]

What are some good textbooks and online resources for learning about geophysics? That is, physics, as it relates to the earth's geology, shape, and internal structure.
-5
votes
1answer
413 views

Can a shock wave travel around the Earth's curvature?

Can an explosion be felt in the ground on the opposite side of the Earth like from an asteroid? Would planes in the air on that side of the Earth be able to survive? Does the shock waive follow the ...
-6
votes
1answer
548 views

Is it possible that the recent droughts are signs of epic crust failure? [closed]

The full question is: Is it possible that the recent, successive, long droughts from Australia to the West Coast of both American continents are signs of epic crust failure? The question is aimed ...

1
2