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.
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How fast does the Earth's inner-core spin?
How fast does the Earth's inner-core rotate compared to the Earth's daily rotation?
The inner core is always described as a spinning/rotating solid core while the Earth has a single revolution per ...
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Adam and eve story, . Any merit or insane pseudoscience about earth's Crust?
Hi so as a Biology Undergraduate my geology & astrophysicsis lackluster. But I came across this apparently "leaked" (by leaked, a specific copy was classified by the CIA, but the book ...
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Geotechnology: Prove a formula, calculated with unit weights, for void ratio
I don't know where else to post this.
I am reading a Geotechnical engineering textbook by B.M. Das, 6th edition.
Problem 3.1 is as follows:
For a given soil, show that
$$e=\frac{\gamma_{sat} - \...
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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 ...
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What's the distance between the center of mass and geometrical center of Earth (CM-CF offset)?
I asked the same question on Physics StackExchange site. I now know that there are several types of "center" and I can tell, I'm interested in the CM-CF offset (CM = geocenter, CF = center of figure).
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What is the relationship between earthquake risk, magnitude, and distance from the epicenter?
I need a (rough) functional relationship between these three quantities. My initial hypothesis is that the risk $R$ (intended as the probability of a building damage), scales with the square root of ...
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Does this support Hapgood's Earth Crust Displacement Theory?
I'm no Geologist by any standard but I'm quite intrigued by what goes on below our feet.
I came across this article that states there's a new or (confirmed) partially melted layer in the athenosphere (...
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What is the pressure at the center of the Earth?
In the question Does gravity increase the closer to the core you get?, it was determined that gravity reduces to zero at the center of the Earth. That is logical.
However if pressure is proportional ...
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Why does calcium occur together with felsic rocks and magnesium with mafic rocks if calcium is denser than magnesium?
Felsic rocks contain a lot of sodium, potassium and calcium (and a great deal of aluminum), while mafic rocks consist of a lot of magnesium with iron....
Why is this?
Why is magnesium (z=12) in the ...
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Where could I get waveform data on low-frequency earthquakes, very low-frequency earthquakes, volcanic tremor and non-volcanic earthquakes?
I am a marine geology masters student and I am writing my thesis on slow earthquakes. I will include graphs of the most common types of earthquakes:
Low-frequency earthquakes
Very low-frequency ...
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Simple Mathematical Equation for the Geotherm
Hi I need a simple equation (polynomial third straight) for a PerpleX simulation to represent the mantle geotherm. The geotherms I have found on the internet so far (unfortunately I don't have the ...
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Is it possible that the rainbow sand dunes in Death Valley, California were formed by some massive mining in the ancient past? [closed]
I know there is a mainstream answer that thinks the rainbow sand dunes they be explained geologically... I just want to know if it's possible to form those colors and those dunes from mining? And if ...
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Does the global temperature vary daily (hotter and colder days)?
Earth's current average global temperature (i.e. including hot deserts and cold polar caps) is reported be somewhere between 14°C and 16°C (depending on sources and methods).
This temperature varies ...
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Does the high pressure inside the Earth's core contribute to its high temperature?
The explanations for why the Earth's core is hot I found on the internet included:
leftover energy from the Earth's formation
radioactivity of the elements inside the core
friction between the core ...
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How does the rotation of Earth's inner core influence climate?
In the recent paper published in Nature that sugests a 60-70 years inner core rotation cycle, it is said:
Interestingly, the same multidecadal periodicity is also well observed
in the Earth’s climate ...
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Where can I access public sonic well-log data?
I'm doing some research and I'm in need of some well-log data from a sonic tool. I'm specifically looking for a multi-receiver tool with 6 or more receivers if possible.
I've been able to find a lot ...
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How much fresh water could be produced by pumping warm humid air through a pipeline up to the top of a mountain?
I have been doing a lot of research on the Internet lately about various desalination processes which are being used today and this led me to begin studying about mountain weather and the orographic ...
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What is the purpose of wavelet extraction from the seismic trace?
I would love to know what exactly we can do with the extracted wavelet. What kind of information extracted wavelet can contain?
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Why were the Interglacial periods in the early Pleistocene spaced about one million years apart, but recent ones only 100,000 years apart?
The Teglen (or Tiglian) interglacial period began after approximately half a million years into the Pleistocene, and the next interglacial (Waalian) occurred about a million years after that.
But the ...
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Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?
Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead.
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Coriolis parameter approximations
When solving equations involving the Coriolis parameter $f = 2\Omega\sin{\varphi}$, I often see the $f$-plane (constant) or the $\beta$-plane (Taylor expansion) approximations.
If I'm solving ...
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Relation between highlands and tidal forces
Could the presence of mountain ranges in continental areas near to tectonic plates boundaries prevent these plates from swaying up and down as a result of vertical tidal forces and plastic ...
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Why is some ocean on continental crust?
While most ocean crust is formed from oceanic plate formations there are areas of the ocean (much of the Gulf of Mexico, Eastern US coast, North Sea, Arabian coast of India) which appear to be ...
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Distribution of terrestrial impact craters
Recently I was looking at a map of known impact structures and I noticed that they are concentrated between the tropical and arctic latitudes, but there is very little near the equator. I can think ...
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What makes special a volcanic pipe to be stable until the mantle?
Comming from this question:
Can we really travel through earth's core?
I wonder what makes special a volcanic pipe to be stable since the mantle through the surface, in comparison to our try or ...
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How much water is the atmosphere losing to space?
Up until recently, I was under a (wrong) impression that the amount of planetary cumulative water resources was finite as I believed its escape from the atmosphere was impossible. I believed that, ...
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Where can I find an anisotropic PREM-like model for Earth's interior?
So, I just discovered PREM (the Preliminary reference Earth model) which models the density distribution of matter inside the Earth to any depth.
The PREM is very convenient but since it only depends ...
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Is it possible for tsunamis to occur on deep water planets?
Assume a water planet with an ocean depth of about 200-500 km.
Would a very strong ground-quake happening at the very bottom of the planet's ocean floor be able to cause a large tsunami to rise up to ...
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Least equatorial ( and tidal) bulge consistent with modest amounts of water in polar regions
In World Building I asked a question about the climate of an hypothetical planet.
There Vogon poet said that
Everyone above 10° latitude will be in permanent drought
Considering that there were no ...
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Is there any free indexed journal that Geoscience students can publish?
I am planning to publish a paper related in Geoscience/Geophysics/Seismology within scope of Machine Learning/AI in particular. Is there any Journal that provide free article publishing for ...
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Under which conditions would you see the MOST lake effect precipitation?
It's well known that the Great Lakes produce large amounts of precipitation in the Fall. When cold polar air moves over the lakes it causes large amounts of relatively warm moist air to rise, ...
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How do Rossby Waves in the ocean form?
So on land, I believe that one factor in their formation is due to inhomogeneities in surface heating between land and ocean (and also inhomogeneities in surface heating due to terrain effects like ...
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In quasi-geostrophic frontogenesis, what happens if the potential vorticity is negative?
In particular, what happens if the Sawyer–Eliassen equation cannot be solved? I know that a condition for the Sawyer–Eliassen equation to have a solution is $F^2 N^2 - S^4 >0$, which means that the ...
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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....
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What is the difference between a geologist and a geophysicist?
What are the main differences between geologists and geophysicists?
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Can a planet have both magma volcanoes and cryovolcanos?
I know that the Jovian ice moons have been speculated to have cryovolcanos. I was thinking of the ice planet of Hoth from Star Wars and in one of the video games; it has regular volcanic activity. ...
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Seismic velocity relations
I do understand why the seismic velocity decreases with temperature and increases with pressure, but I am not really familiar with the relationship between the velocity with Poisson's ratio. I ...
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Change in earth mass since the time of the dinosaurs
Is there a significant difference in the mass of the Earth between now and the time of the dinosaurs (250 - 75 million years ago)? I was just wondering if the force of gravity on dinosaurs would have ...
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What are these undersea lines all around Hawaii?
On Google Earth, there are these radiating undersea lines all around Hawaii:
Here with a bit more contrast:
Unlike the other lines, they are pointed away (or toward) a single place.
What are these, ...
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Can pumping water into the aquifiers reverse the sinking of cities like Jakarta?
Indonesia decided to relocate the capital, in part due to environmental struggles facing Jakarta:
one of the fastest sinking cities in the world due to the over extraction of groundwater
Source: ...
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What is a Poisson solid and what affect does it have on p and s waves?
What is a Poisson solid and what affect does it have on p and s waves?
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IGRF -13 Geomagnetic field, Calculating Partial Derivatives of Legendre Polynomials
I have been trying to implement the IGRF-13 geomagnetic model on my own in C code. I have followed the equations from the website below and I am getting correct results for the B$_{\phi}$ and Br ...
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Could a nuclear explosion in the Atlantic Ocean during the hurricane season trigger a hurricane?
I am wondering if denotating a nuclear bomb in the Atlantic Ocean during the hurricane season could trigger a hurricane.
For example, say that a 100-megaton bomb was loaded onto a ship and that ship ...
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Ways of detecting underground bodies of water
I saw one way to achieve this using the magnetotelluric way, but I need some solid fundamental way to understand it. Any book recommendations would be appreciated.
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On geostrophic wind. How can the Coriolis force cancel out the pressure gradient force when they are mutually perpendicular?
If we are in Northern Hemisphere and there is a point where there is a high pressure, denote it by H, and there is a point where there is low pressure, denote it by L, (for simplicity assume them to ...
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Can an igneous rock have a Vp of less than 1000 m/s and need blasting to excavate?
I have run a 60 m refraction seismic line on a mountain summit. The environment was noisy (wind would be the principal agent) and quite difficult to pick first arrivals. It resulted in 800 m/s.
A ...
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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 ...
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Airborne geophysical survey in steep and undulating terrain. What is more important, energy conservation or orienting lines wrt to geology and why?
I am trying to design a cost and energy efficient aerial survey and have come up against the question, 'do we have to fly straight lines perpenducular to geology?' as not doing so could make for a ...
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Predicting rock type from seismic processing
In reflection seismology, we create a source with an airgun and then use receivers to register acoustic waves (an approximation) at the surface. From these measurements, we can predict a velocity ...
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Is there a way to calculate crater depth?
For the sake of the example, let's assume a crater on Earth roughly twelve miles in diameter.
Is there a way to calculate a range between how deep or shallow this crater would be?
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