Questions tagged [earthquakes]

Questions regarding a sudden release of seismic waves into the Earth's crust. As well as the causes of earthquakes, their consequences and physics.

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1answer
345 views

What is that spooky humming sound heard in earthquake footages?

In most of the earthquake footages filmed outside during the earthquake that hit Mexico City on September 9, 2017 there was a distinctive streak of hum in rapid succession that could be heard in the ...
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356 views

Effects of Mexican Earthquake in San Andreas Fault Line

Could the recent 8.1 Magnitude Earthquake at the Cocos and Nazca plates off the Mexican coast have a knock on effect to the Pacific and Juan de Fuca Plates further north at the San Andreas Fault Line?
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Can hurricanes set off earthquakes?

Large hurricanes can show up on seismographs. Do they do this by shaking the ground with wind? Moving large amounts of water putting weight on the tectonic plates? A large earthquake is the result of ...
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3answers
2k views

What are the distinguishing features of an “artificial seismic wave” (e.g. a large underground explosion)

IN the NPR news item North Korea Possibly Conducts Sixth Nuclear Test, South Korea Says: The U.S. Geological Survey says it detected a 6.3 magnitude "possible explosion" near Sungjibaegam, North ...
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1answer
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Why do human populations concentrate near fault lines, volcanoes, etc.?

I've noticed that many places with large populations tend to be prime zones for natural disaster. Examples: Silicon Valley = earthquakes, Houston = hurricanes and floods, Japan = tsunamis and ...
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2answers
116 views

Earthquake database for fault

I am trying to understand Deterministic Seismic Hazard analysis for which I believe seismic waves corresponding to a seismic sources (such as faults) are required to prepare the Gutenberg Richter ...
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0answers
740 views

Where are earthquakes felt more: on top of a building or on the ground floor?

I have this notion that at the top, the building will be more likely to shake than at the bottom, where it is grounded. So, how does it work with an earthquake? Who would be more likely to perceive a ...
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2answers
610 views

Seismometer records ground displacement or acceleration

I believe Seismometers record ground displacement. However, I have also read in certain articles that this can be ground displacement or acceleration depending on the frequency of the seismometer. ...
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69 views

How did the The Fukushima Nuclear Disaster affect Japan's vegetation? [closed]

I am working on an important project please help!
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1answer
372 views

How to calculate cumulative moment magnitude?

What is the proper way to calculate cumuluative moment magnitude if I know the moment magnitude of several earthquakes?
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1answer
296 views

How to interpret seismic interferometry data?

Here is a screenshot of coseismic interferometry measurements of the 2015 Nepal earthquake. What does it mean? The star is the epicenter of the earthquake. The screenshot was taken from the UNOSAT ...
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Comparing the 4th of August 1998 earthquake to the 16th of April 2016 earthquake in Ecuador

I'm doing an assignment where I'm comparing the two mentioned earthquakes, and trying to figure out which factors played a role in the amount of casualties. In the 1998 earthquake there were only ...
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1answer
706 views

seismic wave detection standing at the epicenter

If a person is to stand at the epicenter of an earthquake. Is it true that he would not detect P-waves nor S-waves echoing off the mantle core boundary? Since if P-wave that enter perpendicularly ...
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1answer
217 views

How could an earthquake be stopped once triggered?

A fault that ruptures causing an earthquake, can cause a chain reaction of dynamically triggered earthquakes in nearby faults, thus causing a much larger seismic event. What could be some unlikely ...
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2answers
109 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 ...
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1answer
2k views

Using accelerometer as a seismograph

I'm using ADXL345 accelerometer with Raspberry Pi to build a seismograph. I've successfully hooked it up and can plot the accelerometer data in three axis. Is there any way to express these data in ...
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2answers
622 views

Why did it take so long to discover the volcanic nature of mid-oceanic ridges?

I just read this article and was astonished to see the following: Oceanographers stumbled on [the mid-oceanic ridges'] volcanic nature in 1973. What I find surprising is how recent that is. ...
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1answer
1k views

Can large earthquakes happen few times at same place(in days)

I want to know if large earthquakes can happen twice in the same place? I live in Istanbul/Turkey. In Canakkale/Turkey too many earthquakes happen for days! I know it is normal for this region but 4.8 ...
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2answers
765 views

What would happen if magma flows into a very large oil deposit?

If there were an earthquake that somehow cause a crack in the earth and allowed a significant amount of magma to flow into a very large oil deposit. With that high amount of explosive energy that ...
5
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1answer
68 views

Is “seismic energy released” a regionalized variable and can be analyzed using geostatistics?

In geostatistics, we can assess and analyze regionalized variables. Tectonic stresses releases in seismically active regions by occurring earthquakes. We can calculate and estimate the seismic energy ...
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1answer
647 views

Evidence for “earthquake storm” at the end of the Bronze Age

The decline of the large population centers around the eastern Mediterranean at the end of the Bronze Age has been associated with a set of large earthquakes ("earthquake storm") occurring between ...
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1answer
178 views

Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake - could this really be useful for warnings?

Edit: Two new items may shed more light on this question: BBC: Gravity signals rapidly show true size of giant quakes links to: Science: Observations and modeling of the elastogravity signals ...
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0answers
103 views

What is the plausability/legitimacy of the San Andreas Fault 'Big One' Megaquake mechanism?

In the ScienceAlert article "New estimates suggest the 'big one' in San Andreas could be much worse than we thought" they make the claim that: Researchers have forecast a mega-quake running the ...
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2answers
160 views

How do they know the 2016 Kaikoura (NZ) Earthquake was 'complex', involved six different faults?

The BBC news article New Zealand quake: The geological impact of a 'complex' tremor says: The powerful earthquakes which hit New Zealand were some of the most complex ever recorded, say scientists. ...
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2answers
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Does the moon have any affect on earthquakes being created? [duplicate]

Here, in New Zealand, we just had a 7.5 magnitude earthquake hit. Alot of people are saying that the super moon caused this. I have doubts as to the super moon actually 'causing' it but could have it ...
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1answer
271 views

Are there any seasonal or diurnal trends in earthquakes?

Though I imagine it's unlikely there is any significant correlation because daily and annual temperature variation really only impact a fairly shallow layer of the crust, I wondered whether the actual ...
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1answer
2k views

Can two earthquakes happen at the same time?

I wanted to know if two earthquakes can happen at the same time in the same area? I "think" this can happen, but I'm not totally sure? I understand tectonic plates sliding against each other can cause ...
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1answer
2k views

Earthquakes at plate boundaries

I was looking into tectonic plate boundaries and earthquakes with pictures like these One thing that is quite obvious is that some of the plate boundaries have very thin zones of earthquakes, ...
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1answer
141 views

Relationship between tides and earthquakes

Ide et al. (2016) suggest that earthquakes (especially those of high magnitudes) are more probable during periods of high tidal stress (during full and new moons). While they show a comprehensive ...
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1answer
83 views

Is the concept of seismogenic zone still relevant after the 2011 Japan earthquake?

The concept of subduction seismogenic zone, where megathrust seisms occur in a layer between an upper and a lower limit is well documented in the 1990/early 2000 literature : Some example : Pacheco,...
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1answer
99 views

Earthquakes and mountain height

Tectonic plate motion is the main reason for earthquakes in Italy. I suppose that a large motion produces higher mountain (as Monte Bianco, Monte Rosa or Adamello) and strong earthquakes. But strong ...
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1answer
298 views

Fault representation

In most illustrations and diagrams of the types of faults, there is always something similar. I noticed that there is a side of the hanging wall and foot wall which is slanted. We're supposed to make ...
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1answer
164 views

Are the other causes of an earthquake (e.g. volcanic eruptions) the cause of the “sudden slip” which is the main cause of an earthquake?

I am to deliver an informative speech about earthquakes in class. However, I was not the first to talk about earthquakes and his discussion of the cause of earthquakes is different from mine. He ...
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3answers
966 views

Why is a mild earthquake often mistaken as dizziness or vertigo?

Is it due to the longitudinal nature of the seismic waves? When a heavy bus or truck goes by at high-speed, the shaking in nearby ground is not mistaken as dizziness, rather the feet and body feel a ...
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1answer
1k views

Seismology: What causes an earthquake? [closed]

I am doing a research on earthquakes but I cannot fully understand what causes earthquakes. "Caused by a sudden releases of energy by the Earth's crust, causing seismic waves which causes the ...
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1answer
47 views

Is there a formula to compute the destructiveness of an earthquake?

I am trying to find out if there is a way to compute if an earthquake is destructive. I am looking for a threshold formula which depends on magnitude and depth for example ...
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1answer
590 views

Epicenter of earthquake at sea - is it a point on ocean surface or sea bed?

When an earthquakes' focus is below the sea bed, is the epicenter given as a point on the oceans' surface at mean sea level, or as a point on the sea bed? There is some ambiguity in the term 'earths ...
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2answers
602 views

Spatial extent and predictability of various hazards.

My question concerns the following three hazards: earthquakes, hurricanes and drought. In terms of spatial extent (wide spread, limited), I believe that earthquakes generally have the most limited ...
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1answer
723 views

Can earthquakes affect the atmosphere?

Recently an earthquake of magnitude 6.9 shook the northeastern region of India, where I live. After the earthquake, the climate has changed dramatically resulting in excessive hail showers, ...
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1answer
66 views

Does the increasing number of significant earthquakes relate to increasing population density in earthquake zones?

I've discovered that there's two different sets of data for earthquakes - one for actual number of earthquakes, and ones for only significant numbers of earthquakes. For example, in January 2016 the ...
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2answers
123 views

How to determine constant $C$ in $p(x) = Cx^{-D}$?

Given a distribution obeying the power-law (fractal) relation, such as the cumulative distribution function $L_{cf}(> X) = CR^{-D}$, if $X$ is given, how does one find the constant $C$ from a given ...
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1answer
124 views

Has the Olema earthquake fence continued to spread apart?

The earthquake fence at Olema shows the sudden transform motion along the San Andreas caused by the 1906 earthquake. 110 years on, has there been ANY additional displacement?
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1answer
4k views

What happens if a magnitude 13 earthquake occurs?

What would happen if a Richter magnitude 13 earthquake occurred? I read (at http://www.tulane.edu/~sanelson/Natural_Disasters/impacts.htm; about halfway down the page) that if a comet were to ever hit ...
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0answers
33 views

Earthquake data acquisition Geosig VE-53

Is it possible to receive data from a Geosig VE-53 to a PCI data acquisition (serial port) connected to PC and without using a recorder?
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5answers
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 ...
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2answers
11k views

How to compare earthquake magnitudes

On the USGS website, it says Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; However my book says ...
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2answers
126 views

Earthquakes in Oklahoma influenced by Humans?

I'm currently living in Oklahoma, and there has been an abnormal amount of earthquakes lately, by abnormal I mean more then 5 in a day(not sure if that's normal or not).. I've also been told that in ...
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2answers
649 views

Is it possible to prevent high magnitude earthquakes by induced earthquakes?

As we know, earthquakes can be induced by human activities. Can we induce earthquakes around faults regularly so that the energy releases regularly, and hence prevent high magnitude earthquakes by ...
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1answer
622 views

Are volcanoes formed from earthquakes?

I know that some earthquakes are caused by volcanoes and that some earthquakes can trigger volcanic eruptions close to where the earthquake is. But what if a great earthquake(8.0 or above) occurs and ...
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1answer
70 views

Hazard event predictions. Examples of predictions causing more harm than good

Could anyone give me any examples of attempts to predict earthquakes AND tropical storms that have caused more harm then good (e.g: because an area was predicted to have low levels of risk and ...