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
3
votes
2answers
106 views

Aspiring Geophysicist

I am interested in becoming a geophysicist. I am currently doing my undergraduate degree in the UK but have not chosen a specialisation. Is it better to specialise in Earth Sciences as an undergrad or ...
3
votes
1answer
70 views

If the accuracy of measurement of the earth's volume is not known, how can scientists assert that the earth is not expanding?

Volcanic eruptions, undersea earthquakes, fissures in the crust, meteoroid accumulation could all be seen as empirical evidence of expansion of the earth. Sink holes and other phenomena could be ...
3
votes
1answer
183 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....
3
votes
1answer
1k views

What is the difference between radiation balance and the global energy balance?

Looking at two diagrams below, they seem to depict the same system. How are they different? Why one is a radiation balance model and the other a global energy balance model? RADIATION BALANCE MODEL: ...
3
votes
3answers
277 views

How probable is is that earth magnetic field will change 180 degrees at once?

Today the Earth's magnetic field is moving a little bit. But is there going to be a point where the field suddenly radically changes direction? If so what is the cause of that? If not, then is the ...
3
votes
1answer
112 views

Factor 1000 in mixing ratio formula

I am seeing two different formulas for the mixing ratio, which differ by a factor 1000. To be more specific: $w = 0.622 \cdot (e/p)$ and $w = 1000 \cdot 0.622 \cdot (e/p)$ where $e$ and $p$ are the ...
3
votes
1answer
561 views

What structures form due to the melting of subducting plates? [closed]

What structures form from the melting of subducting plates? Plutons, Accretionary wedges, Deep sea trenches, Faults?
3
votes
1answer
592 views

Rossby radius as horizontal scale

In the introduction of "Geographical and monthly variability of the first baroclinic Rossby radius of deformation in the South China Sea", the authors states: In both theoretical and observational ...
3
votes
2answers
116 views

Is there any case that changed from earthquake safe zone to danger zone?

Is there any case that changed from earthquake safe zone to danger zone? As plates move, I think that earthquakes belt will change over time. But is there really a case in which the earthquake-safe ...
3
votes
2answers
2k views

Effect on poles when Earth is not tilted [closed]

Say a Mars size object hits the Earth in such a way that it knocks the Earth in a straight 0 degree angle, and let's assume that we somehow do not go extinct. What would happen to the poles in this ...
3
votes
1answer
90 views

Simple way to understand these narrow frequency peaks in recently published “ice shelf singing”?

The Earther.Gizmodo.com article Scientists Discover a Weird Noise Coming From Antarctic Ice Shelf links to the American Geophysical Union video (an more importantly audio) (AGU) This is what an ...
3
votes
1answer
98 views

Where on Earth is the highest none polar magnetic fields?

Is there anywhere that magnetic ore deposits are strong enough to have a magnetic field that would be stronger then Earths' magnetic poles by proximity? I'm not asking Where on Earth is the ...
3
votes
2answers
2k views

What exactly are enantiotropic and monotropic polymorphic transitions?

Recently, I've been studying the subject of polymorphism and met two important concepts, the monotropic and enantiotropic polymorphic transition types. However, I can't really seem to grasp the ...
3
votes
1answer
117 views

Do our continents lay on the mantle because solid silicon dioxide is less dense than its liquid form?

I don't know whether quartz behaves like ice or not, but could it be because silicon dioxide, which the continents are made of for a big part, is less dense - so the continents lay on top like ice on ...
3
votes
1answer
128 views

Equations for Milankovitch Factors?

Are there equations for the radiative forcings of the three Milankovitch factors at any given time? Or a database of values?
3
votes
1answer
86 views

gamma-ray spectrum vs energy decay

I am going through An Introduction to Applied and Environmental Geophysics, a book by John Reynolds (2011), to better understand radiometrics and gamma-ray spectrometry. The author provides some ...
3
votes
2answers
144 views

Why do buoyantly rising mantle minerals melt, yet buoyantly rising atmospheric waters condense?

In the mantle, minerals contained in buoyant plumes of rock undergo phase changes from solid to liquid (decompression melting). In the atmosphere, waters contained in buoyant plumes of air undergo ...
3
votes
1answer
82 views

How much of the Earth's heat is caused by the hot centre?

What is the percentage of the Earth's warmth that the Earth's hot centre is responsible for? What would be the temperature of the atmosphere if the Earth's centre was 18° C (average temperature on the ...
3
votes
1answer
111 views

Quantitative mapping of air pollution Sifakis and Paronis

I am reading this paper about deriving AOT and I have found this ...
3
votes
1answer
86 views

How does the changing seasons affect the large scale easterly flow of the ITCZ?

I am new to climate science and have been learning the basic picture of the intertropical convergence zone (ITCZ) and how this leads to the predominant easterly "trade winds". The picture that I ...
3
votes
1answer
62 views

Rain Water vs Sprinkler Irrigation

During the rainy season, the crops like corn, cotton are found to be growing faster. Studies shows that the thermoelectric fixation of gaseous Nitrogen during rain storm accelerates the plants growth ...
3
votes
1answer
57 views

Is there any possible future for high energy geophysics? If so how it is going to revolutionize our knowledge about Earth's interior?

How practice is to map/image the subsurface of the earth using the high energy particles like neutrinos? https://www.geosci-instrum-method-data-syst.net/special_issue2.html
3
votes
1answer
313 views

Open source well information viewer

I am in the middle of a hobbyist experiment and would like suggestions on an open source HTML viewer for mud loggging, FMIs, lithology and seismic. I have used INT before but for this project I would ...
3
votes
1answer
136 views

Is there a high-temperature, non-magnetic glue that doesn't dissolve in water?

I have very small mineral samples, and I'm looking for a glue that can hold them through a sample preparation process that I'm doing: heating, polishing, and measuring magnetic moment. For that I want ...
3
votes
2answers
262 views

Conditions at the bottom of a VERY deep hole

I'm a science fiction author looking to describe what conditions might be like at the bottom of a cylindrical shaft ~ 30 meters across and ~ 35 km deep. It's located somewhere on the edge of ...
3
votes
1answer
640 views

Seismic data processing software

For processing seismic data, why is Seismic Unix so important? What distinguishes it from other seismic processing software like GLOBE Claritas or Omega? Is it argued that processing capabilities are ...
3
votes
1answer
66 views

Energy Density of Porous Rocks

It's very long, I know. But please, don't be discouraged from going through this question if you can help me. The question is at the second to the last paragraph, but you need to read through to ...
3
votes
1answer
68 views

If the top layer of a large river freezes, is the remainder's rate of flow affected?

This question is a hypothetical, and has to do with the notion of cheap, modular turbines that can be sunk and anchored to a specific depth in a body of water. Each would not generate much power, but ...
3
votes
1answer
86 views

Wave train 200 m/s meaning

I ran a 60 m line intended for surficial seismic refraction. Energization with hammer. 12 (10 hz vertical 5 m spaced) geophones and 5 shots (15 m spaced). Record length 0.5 s. Thanks to a borehole ...
3
votes
1answer
77 views

What voltage and/or amps cannot be found naturally?

Electricity can come in many forms on Earth but when is amps and/or voltage limited physically on Earth? In other words, what voltage arises naturally on Earth?
3
votes
1answer
148 views

Which component in a 3-component Sp receiver function is the actual Sp RF?

In a 3-component Sp RF I have the green's function in P,SV, and SH. The actual component to the RF that shows the Sp conversion (the one always published in the literature), which would represent as a ...
3
votes
0answers
34 views

How long for tectonic plates to develop from a planetary, molten planetary surface?

On Earth or an Earth-like planet, how long does it take for a molten surface to solidify into planetary crust, and how long does it take for that crust to develop into tectonic plates?
3
votes
0answers
153 views

Cratonization - how did the Archean cratons form?

Before the onset of modern style plate tectonics and the Wilson cycles in the late Archean, it is thought that smaller units of continental crust, called cratons, roamed the oceanic crust over a more ...
3
votes
0answers
37 views

What is the minimum temperature difference to drive mantle convection?

The condition for convection to cease is that the Rayleigh number $$\mathrm{Ra}=\frac{g\rho\alpha L^3\Delta T}{\kappa\nu}\lessapprox 10^3.$$ For the Earth's mantle I have seen estimates of $\mathrm{Ra}...
3
votes
0answers
45 views

Why an inertial gyro has a frequency and a geostrophic gyro does not?

Inertial flow is given by the balance between Coriolis and centrifugal forces. A geostrophic flow is given by a balance between Coriolis and the gradients of pressure. The frequency of the inertial ...
3
votes
0answers
15 views

transition elastic deformation to flow

Let's assume a small (and smooth) vertical deformation of the seabed. If done quickly, I can consider it a vertical force generating an acoustic wave in the water, where every particle of water ...
3
votes
0answers
31 views

How do people determine initial ratio of the parent nuclide and daughter product in radiometric dating?

I understand that we have zircon crystals that prevent entering or leaving of nuclide or lead after forming. But how cand we understand what was the initial ratio?
3
votes
0answers
76 views

What gravitational evidence do we have to counter the idea that oceans are formed when continents sink?

Is there some evidence for this based on gravity anomalies? I think I know how to tell if a mountain or structure is compensated based on bougeur and free air anomalies, but this really has me ...
3
votes
0answers
61 views

Capillary rise experiment and obtainable information about the porous medium

I have access to rock core(s) and vacuum saturation chambers as seen in the image below. I can dry the rock core using an oven, measure its geometry and mass. I can place it into the vacuum ...
2
votes
3answers
3k 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
2answers
8k views

Is winter hotter at the Equator?

I live in the Northern Emisphere. One of the things I have been taught when I was in high school is that winter is colder than summer because in that season we're at an unfavorable angle and nights ...
2
votes
2answers
434 views

what is the best way to actually make the Earth lose heat?

I know that refrigerated air just moves heat around, and creates more by using fossil fuel energy in the process. If we wanted to actually reduce the amount of net heat energy in an area on the ...
2
votes
2answers
132 views

What is the simplest meteorological model to operate?

For teaching purposes I am looking for an atmospheric model that can be easily installed and the input data can be easily read and prepared. Preferably I would like to run a global low resolution ...
2
votes
3answers
423 views

Why Do Supercontinents Form? [duplicate]

It would seem, on the face of it, improbable that the continental land-masses would accumulate into a single composite, yet it has happened numerous times, and is expected to again in the future. ...
2
votes
2answers
103 views

What causes the earth to be a good grounding system?

When working with electricity, rubber shoes are recommended because they prevent current from running through your body. But I've read that usually the earth is more negative charged than positive. ...
2
votes
1answer
2k views

Why are oceans so deep?

Some areas of oceans are about 11 km deep. Is it because continental plates were moving away because of troughs in the middle from where new rock is formed? If so, why did it become deep? If not, what ...
2
votes
3answers
76 views

stretch phenomena after NMO application on seismic data

after the NMO application we have stretch for far offset , i read a lot of articles but i can't have a complete idea how this phenomena is really created ! any one have a rich explanation ?
2
votes
1answer
42 views

Variation of the atmospheric pressure

By Hydrostatical Law, $p_a = \rho gh$, at a given $h$. However density varies with altitude and with temperature. Temperature varies by altitude. $g$ constant varies with altitude. How to express the ...
2
votes
1answer
158 views

Which ocean is going to be swallowed by the Supercontinent Cycle, Atlantic or Pacific?

The register shows several supercontinents have been formed on Earth's History: "The most recent supercontinent, Pangaea, formed about 300 million years ago (0.3 Ga). There are two different ...
2
votes
1answer
141 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
5 6
7
8 9