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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691 views

Nepal earthquake of 25 April 2015

On the 25th of April at about 11-12pm, an earthquake whose epicenter was in Nepal was felt with a magnitude of 7.5 in Delhi NCR, as well as in other Indian states (Rajasthan, Bihar, Jharkhand, and ...
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140 views

Seeming correlation between time of day and earthquakes

I live in a generally geographically active area (Southern California, near the San Andreas fault, if that matters), that has had two relatively minor earthquakes that I have felt in the last week (in ...
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Calculating the displacement of a fault

In the calculation of scalar moment magnitude of an earthquake we have the formula $$M_0=\mu AD$$ where: $\mu$ is the shear modulus of the rocks involved in the earthquake (in Pa) $A$ is the area ...
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259 views

Can a 99.9% probability of an M≥ 5 earthquake within a 3-year period be verified?

Paper: Potential for a large earthquake near Los Angeles inferred from the 2014 La Habra earthquake (2015) Obviously there has been much discussion on the viability of earthquake prediction. This ...
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778 views

What is the most powerful natural catastrophic event on record?

Natural catastrophic events such as hurricanes, earthquakes, volcanic eruptions and meteor impacts releases vast amount of energy. What is the most powerful single event of such nature ever recorded ...
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Are strong deep earthquakes that result in minimal impacts common?

Happened to see notice of fairly strong earthquakes near Fiji and Peru within the past few days, and thought I'd find they had been fairly damaging... only to find the impacts were quite minimal. ...
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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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258 views

Predicting earthquakes using disturbances in DTH TV transmission

It is said that before an earthquake happens, a viewer experiences disturbances in DTH TV transmission in the form of distorted images on the screen which automatically correct after a few seconds. ...
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750 views

Where does the 2015 Nepal earthquake rank amongst earthquakes since 1900?

Wikipedia provides a list of deadly earthquakes since 1900. Where would the April 2015 Nepal earthquake (magnitude currently estimated as 7.8 or 8.1) rank in this list, in terms of magnitude?
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About Earthquakes and their properties

I know this sounds like a crazy observation but San Francisco has a lot of HUGE buildings in the downtown area , millions of tons or probably more. Many Scientists think a big earthquake there is '...
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2k views

Why are there more intense earthquakes in Iran than in Iraq?

Why are there more intense earthquakes in Iran than in Iraq, if they are so close together? I often hear news items of earthquakes in Iran that are higher on the Richter Scale than those that happen ...
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What is a fault?

Curious if to what degree it is possible to cluster epicentres as originating from a single formation/fault? Seems like it is possible that apart of the issue might being able to map the hypocentre of ...
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283 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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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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154 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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249 views

Will another big earthquake hit Kathmandu?

Recently, we got the news that the western part of Nepal may be hit by a larger earthquake than that of April 25, because it did release all of its energy. During the earthquake, only the eastern part ...
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What geological structure(s) is responsible for the recent Queensland earthquakes?

Recently, south-east Queensland has been rattled by 2 moderate earthquakes - a 5.3 a couple of days ago (News report) and a 5.7 tremor just a few hours ago as of writing this post (News Report). These ...
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Question about earthquake data attribute codes

I have some earthquake data with an attribute field call M and has values c, h , l , m or w. There is another one called Magnitude so I assume its not that. Any ideas what M represents and what the ...
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Can large earthquakes happen twice/thrice at the same place within a short timeframe

I want to know if large earthquakes can happen twice in the same region? The reason is that the recent earthquake in Nepal was followed by many after shocks of considerable magnitude. I wanted to ...
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595 views

Why is the Ring of Fire there? [duplicate]

The Ring of Fire goes through the places that have the most earthquakes. Why is the Ring of Fire there, not somewhere else? Any help would be appreciated!
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264 views

Is the whole San Francisco Bay Area essentially one giant fault?

Put another way, if you go back far enough in earth history, was there never a San Francisco Bay, and the mountains in the Peninsula and east of the "East Bay" were essentially a contiguous mass of ...
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217 views

How significant is human influence on seismic activity?

Here's a graph from johnstonsarchive.net showing energy released by earthquakes and, however reliable this graph is, it shows huge differences in earthquake activity. About how big percent is the ...
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150 views

Lights associated with earthquakes?

According to the New Madrid, Missouri web site, during the 1811-1812 earthquakes there were reports of lights coming from the ground due to quartz crystals being squeezed. They call this phenomena “...
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681 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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589 views

Megathrust earthquakes on subduction zones

I am a beginner in geology and earthquake studies, and learning about subduction zones recently. Question is: do large earthquakes (sometimes referred to as megathrust quakes) occur on any point in ...
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332 views

2018 Swan Islands earthquake tsunami

How come the strike-slip 7.6 M earthquake, occurring January 9th, 2018, produced no tsunami? Has there ever been any produced in this region?
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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 ...
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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 ...
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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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77 views

largest earthquake not in a subduction zone

Whats the largest earthquake since 1900 that was not in a subduction zone (not a megathrust). Wikipedia says that Since 1900, all earthquakes of magnitude 9.0 or greater have been megathrust ...
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561 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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71 views

Would epicenters in less-deep areas of ocean tend to reduce the impact of a resulting tsunami somehow (wave “breaks” before getting there?)

I just felt an earthquake at in a 6 floor building in Taipei, where I am familliar with how they have felt over the years. This one felt particularly vertical, and made me feel queezy, while most ...
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67 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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80 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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268 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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110 views

Do higher global temperatures increase volcanic activity and earthquakes?

I've read that when global temperature increases significantly, liquid magma can make it's way closer to the surface of earth, causing increased volcanic activity and earthquakes. Is there scientific ...
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400 views

Why do some earthquakes and volcanoes occur within plates?

I know that volcanoes and earthquakes occur on plate margins. But, do some of them also occur within plates?
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Why do loose, soft soils amplify earthquake vibrations rather than dampening them?

Areas where the buildings are built on top of a deep layer of loose sediments are widely recognised as being more prone to earthquake damage (all else being equal) than areas where the bedrock is ...
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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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54 views

Catalog of all significant earthquakes since 1900?

Where can I find a list of all earthquakes that happened on Earth since 1900?I need time, longitude/latitude, and power -- preferably in .csv format.
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291 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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599 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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136 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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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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Confusion on the Nepal earthquake expert statements

Nepal hit by second huge earthquake and more are still to come Equally big earthquake coming in eastern region of Nepal Nepal quake followed historic pattern The experts on mentioned on the first ...
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Why do major earthquakes keep happening in Lombok recently?

So I've been following the situation in Lombok, Indonesia from both online news and friends on the ground. One thing that I can't seem to figure out is why there are so many earthquakes over an ...
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143 views

Is it dangerous to live in Seattle due to the earthquakes?

I'm considering a move/vacation to Seattle, and I'm concerned it may be dangerous due to the risk of an earthquake?
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What is a “tar shower?”

I'm reading about Sodom and Gomorrah on Wikipedia when I come across this: "One such idea is that the Dead Sea was devastated by an earthquake between 2100 and 1900 BCE. This might have unleashed ...
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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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96 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 ...