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.
176
questions
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1answer
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What Magnitude does it Feel Like when Far Away in an Earthquake?
I can't find a good way to say this but, if I had some info about an earthquake (i.e. magnitude 8, originating in water) and if I had a distance (i.e. 850 miles/ 1370 km) could I calculate what it ...
2
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1answer
32 views
Difference between Earthquake Seismographs
How can we tell the difference between a seismograph of a local earthquake and that of a distant earthquake?
2
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0answers
39 views
Farallon plate subducting under North American plate: is it a factor in “the next big one”?
I am a writer, not a scientist of any kind. I live in the SW AZ desert (USA), so we get earthquakes from time to time. I grew up in southern CA, right next to the San Andreas fault, so I have a ...
1
vote
1answer
50 views
Recent high seismic activity in Europe
It seems that Europe and the Mediterranean Sea have had high seismic activity in last six months. Major events which I remember are:
2020 Aegean Sea earthquake, magnitude of 7.0 Mww
29 December 2020:...
2
votes
1answer
102 views
What is this long mark undersea
Visiting Google Maps, I came across this long, sinuous, while pretty regular mark undersea that looks like an ancient river, when the sea was way lower, or a big (big!) boulder that could have rolled ...
3
votes
1answer
44 views
Is there any information on the height of waves near New Zealand resulting from today's M 8.1 Kermadec Islands earthquake?
The video in this tweet shows the small wave produced at Tokomaru Bay in New Zealand following the M 8.1 - Kermadec Islands, New Zealand 2021-03-04 19:28:31 (UTC) event. These are so far the only ...
2
votes
3answers
98 views
Is an Earthquake Large Enough to Cripple the Entire West Coast of North America Possible?
I have an idea for a novel I want to turn into a reality, and I'm starting some research first to make my book at least plausible in very specific conditions. The main aspect of the story would be ...
2
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0answers
48 views
Is it possible for Mexico to have a magnitude 9 earthquake?
Everyone has heard of the Cascadia Subduction Zone and the potential threat it poses. However, I have heard nothing about The Cocos Subduction Zone, even though it caused a devastating earthquake over ...
4
votes
1answer
94 views
How much time is there between an underwater earthquake and the moment a tsunami hits the coast?
Tsunamis can be caused by underwater earthquakes, like the 2004 tsunami in the Indian Ocean. The precise value will likely depend on where the earthquake is relative to the coast. But what is the time ...
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0answers
19 views
Seismic activity in the UK [duplicate]
On 8th September 2020 there was a magnitude 3.9 earthquake here in the UK at 51.817°N 0.665°W which is approx. 10km/6.2miles east of Aylesbury or roughly 50km/31miles east of Oxford.
This got me ...
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1answer
69 views
OpenEEW - earthquake early warning by everyone?
This site
https://grillo.io/
and here
https://github.com/openeew/openeew/
advertises such a system. But from the make-up of the site and no geo-science related work that they link to (at least what I ...
4
votes
1answer
61 views
Could the 5.7 earthquake in Utah be a precursor to a larger one?
Trying to verify the validity of a rumor.
https://earthquake.usgs.gov/earthquakes/eventpage/uu60363602/executive
0
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1answer
142 views
How Can Adjacent Parts of an Oceanic Plate be Subducted in Different Directions?
It is claimed by some that the reason for gaps in chains of volcanoes generated by plate subduction is that some parts of the plate dive deep into the mantle and generate magma plumes, while other ...
4
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0answers
52 views
Locating an seismic epicenter
I understand how to find an epicenter using three sensor locations and why three locations are needed. Is it possible, though very improbable, to find an epicenter if you only have two seismic ...
14
votes
1answer
6k views
If a very huge Earthquake occured anywhere on Earth could waves emerge to come together again on the opposite side?
Suppose that a super-powerful earthquake occurred anywhere on Earth, say one with the value 10 on Richter's scale. The quake can have any value but as can be read in a comment below the highest value ...
2
votes
1answer
138 views
Could Rumblings From Plutons be as Ominous as Rumblings From Volcanoes?
Mount Kinabalu in North Borneo is a 10 million year old pluton. A pluton is a magma plume from the mantle which was not able to reach the surface and erupt as a volcano, but solidified underground and ...
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1answer
51 views
Volcanism and Earthquakes in Borneo [closed]
Mount Kinabalu is a 13,400 foot mountain in North Borneo formed by volcanism about ten million years ago. What caused this volcanism, why has volcanism ceased in Borneo, and what was the cause of the ...
5
votes
2answers
148 views
Could an earthquake on flat land still kill someone without any buildings/boulders or such near by?
Suppose you were sitting near the epicenter of an earthquake, sitting down on flat land without much else near by, maybe some grass. Is it still possible that say, a magnitude 8 or 9 earthquake would ...
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vote
2answers
61 views
Is there a general equation to know how big of an area is affected by an earthquake?
If you visit USGS earthquakes listing, you get 3 points of information for each earthquake: Location, depth, magnitude. My question is, is there a way to approximate how big of an area is affected? ...
0
votes
1answer
39 views
Is it reasonable to approximate the swinging building (base of the building) during an earthquake to a simple harmonic motion?
I am thinking of making a model of swinging building during earthquake and study the methods to minimize the swinging.
So does it even makes sense to approximate the swinging buildings (the base of ...
12
votes
3answers
3k views
Would the shaking of an earthquake be visible to somebody in a low-flying aircraft?
If you are in an airplane well above ground level, but low enough to see the faces of people relatively easily, and an earthquake happens, will you see the ground shake?
2
votes
1answer
52 views
What is the lateral ground acceleration, at the fault line, during a strike-slip earthquake?
I've read that peak lateral ground acceleration for magnitude 7 - 8 earthquakes is ~1 g at the epicenter (is that correct?), but I'm wondering if it might be significantly higher right at the ...
3
votes
3answers
100 views
Is this series of earthquakes near Broome, Australia normal?
There have been a series of earthquakes (some strong) near Broom, Western Australia. See this screenshot of the Geoscience Australia earthquakes map:
I didn't believe there were any faults around ...
0
votes
2answers
76 views
Why is it hard to predict earthquakes?
An analogy I came up with is:
Predicting earthquake strength and timing is like throwing a sheet of glass on the ground and predicting how many pieces it will break to and where they'll end up.
Is ...
2
votes
1answer
69 views
What is the vertical axis of this waveform shown in this tweeted IRIS GIF?
This IRIS tweet shows a video of siesmic waves from the recent M6.4 Earthquake in California rolling across the US.
I've made a small GIF to give the idea but the "GIF" in the tweet shows the whole ...
2
votes
1answer
183 views
Do earthquakes produce folds on rocks?
Earth rocks are frequently folded at surface.
Folds in alternating layers of limestone and chert in Crete, Greece.
Source: commons.wikimedia
Are earthquakes the main mechanism ...
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vote
1answer
99 views
What are these basal rip up clasts in North Dakota?
Ther's an graph that appears that the KT asteroid turned the rocks into rubble 3000 km away, else there was a rain of big rocks from the sky.
What are the rip up clasts and what is the way they were ...
3
votes
1answer
58 views
How do I get the velocity of the P-wave or S-wave without using the travel time graph?
I'm trying to write a program that would determine the magnitude and epicenter of an earthquake. From http://www.dartmouth.edu/~ears5/handouts/EQ_distance.html, the distance of the epicenter can be ...
2
votes
0answers
44 views
How can shake amplitude influence the damping ratio and resonant frequency of a soil base structure?
I have performed an experiment using a shaking table to simulate the response of a soil base structure to an earthquake. A multi-floor structure was placed on a sand (90% relative density) bed and the ...
9
votes
1answer
255 views
Could an earthquake create a design in a sand pendulum?
Is it possible for an earthquake to generate such a design in a sand pendulum during an earthquake? I saw an article online describing the story of a shop owner finding one of his pendulums had ...
4
votes
1answer
111 views
What is the largest earthquake attributable solely to volcanic activity
I was recently and for the first time caught in an earthquake. This being my first time, I freaked out and had no idea whether the building was going to collapse or not.
I was later told that this ...
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vote
1answer
61 views
Coal fires affecting seismic activity, and also volcanoes
Can coal fires cause earthquakes to happen, or possibly prevent or postpone earthquakes? Also can coal fires trigger(or prevent) volcanic eruptions by affecting flow of magma underground or by some ...
6
votes
1answer
106 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 ...
5
votes
2answers
77 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 ...
4
votes
2answers
90 views
Are Indonesian 2018 earthquakes related?
Indonesia had multiple major earthquakes this year
A series of earthquakes in Lombok between July and August, including a 7.0 mainshock
The 7.5 earthquake + tsunami in Sulawesi, September 2018
A 6.0 ...
0
votes
1answer
198 views
How likely is that next big earthquake (and tsunami) will hit Philippines again?
We recently had an earthquake in Bali (August 5th 2018), then in Palu, Indonesia (October 1st 2018).
Considering the distance and time between Bali and Palu, is it more likely that it will be near ...
4
votes
0answers
48 views
How do I generate a Moho depth model from seismic refraction data?
There are several permanent seismograph stations in Eastern Canada that have been recording arrival times for over 25 years. Using refracted Pn arrival times from natural earthquakes I would like to ...
8
votes
1answer
248 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 ...
8
votes
1answer
93 views
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. ...
4
votes
1answer
203 views
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 ...
7
votes
3answers
571 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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0answers
61 views
Seismology - PPV / VDV from geophone waveform data
I'm using an inexpensive seismometer to try and measure the effects of local HGV traffic on buildings. The device is connected to a Raspberry PI that has a Cirrus Logic Audio Card. The signal is fed ...
4
votes
1answer
70 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.
1
vote
1answer
287 views
What would a graph of magnitude >7.5 earthquakes over last 400 years compared to Grand Solar Minimums look like?
I am a novice here and I really appreciate the graph of magnitude >7 earthquakes related to 11(22)yr solar minimum cycles.
I was wondering what the correlation would be (if any) if we changed the ...
12
votes
2answers
446 views
Did the Geothermal Power Plant contribute to Pahoa's Lava Fissures?
There was lava in the area near the wells that the Puna Geothermal Venture facility created.
The plant has nine wells that run as deep as 8,000 feet, according to Wil Okabe, managing director for ...
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0answers
63 views
Applicable seismometers data?
I need to study low frequency range of seismic waves (~ up to 0.07Hz). Is it correct to use accelerometers data to compare with synthetic seismograms. Synthetic seismograms are calculated up to 0.07Hz....
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0answers
89 views
Is the probability distribution of earthquakes memoryless?
What I want to know is more specific than the title: If a city sits on major fault lines (let's say Tehran), and has a history of severe earthquakes (greater than 7 magnitude) once every 150 years in ...
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0answers
52 views
Interpretation of horizon display
I am currently working on a project that involves using seismic attributes as input parameters in a neural network for estimation of porosity and permeability for a reservoir. Now, I need to correlate ...
4
votes
2answers
2k views
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 ...
4
votes
0answers
71 views
Conversion of body wave magnitude to moment magnitude
I have been tasked with homogenizing a catalog of events obtained from the USGS website, however, the data is a mix of different type of magnitude measures. How do I convert the different type of ...
