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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32
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3answers
10k views

Is it true that earthquakes are not felt in a cave?

I took a tour of a cave in northern California last weekend. The tour guide asked us, "If an earthquake occurred, what would we feel in here?" My answer was, "fear," but she said we would feel ...
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1answer
48 views

Will California become a subduction zone in the distant future

California is one of the few places in the world that lie on a transform fault. My question is why considering the fact that North American Plate is moving westward shouldn't California be a ...
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3answers
71 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 ...
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0answers
43 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 ...
5
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1answer
85 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
63 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 ...
2
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4answers
1k 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 ...
31
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8answers
3k views

Is earthquake prediction possible?

After the Tohoku and East Coast quakes, I skimmed over several books discussing the validity of earthquake prediction as a discipline, yet found no significant breakthroughs. What should change in our ...
4
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1answer
2k views

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 ...
4
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1answer
59 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
13
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4answers
3k views

Is there a correlation between hot springs and earthquakes?

Is there a correlation between how many hot springs an area has, and how frequent or severe the area's earthquakes are?
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1answer
140 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 ...
13
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2answers
441 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 ...
5
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2answers
146 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 ...
15
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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 ...
5
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0answers
51 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 ...
8
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3answers
535 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?
3
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1answer
135 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 ...
5
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2answers
88 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 ...
3
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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 ...
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1answer
50 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 ...
2
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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 ...
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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? ...
2
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3answers
96 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 ...
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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
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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
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1answer
64 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 ...
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2answers
71 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
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1answer
159 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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1answer
832 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, ...
6
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1answer
181 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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2answers
4k views

Is the epicenter always directly above the hypocenter?

All the graphics I've seen showing epicenters with a hypocenter (labeled focus in the graph below) appear to show that epicenters are always directly above their related hypocenters. Is this correct?
19
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1answer
366 views

What are the physical upper bounds on the magnitude of an earthquake?

Given what we know about the physical mechanisms underlying earthquakes, what do the theoretical upper bounds on the magnitude of an earthquake look like? What physical phenomena impose those upper ...
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1answer
95 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 ...
19
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2answers
841 views

How does one measure what causes earthquakes?

I know that they occur when energy that was previously stored is released in seismic waves. But how is the energy stored in the earth in the first place, and what can trigger the release of such ...
21
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3answers
414 views

Is fracking likely to produce earthquakes?

Post Christchurch-2011 earthquake, there was much concern that fracking in the surrounding areas might lead to further quakes, as was rumoured to have happened elsewhere in the world. Is there ...
43
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6answers
100k views

Are Richter-magnitude 10 earthquakes possible?

The largest earthquake since 1900 according to the United States Geological Survey (USGS) was Richter-9.5 magnitude quake in Chile in 1960. Are magnitude 10 earthquakes possible? If so, what is the ...
5
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2answers
632 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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1answer
3k views

Is there any correlation between Grand Solar Minimums (GSM) and earthquakes? [closed]

I've found many claims arguing that the periods of minimum solar activity are associated with increases earthquakes and volcanic activities. Some of these claims are supported by articles in ...
4
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1answer
50 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 ...
8
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1answer
214 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 ...
9
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1answer
204 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
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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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3answers
3k views

Is it possible for Earth to experience Polar Shift?

Many accounts claim that the Magnetic Field of the Earth has been seriously degrading for the past centuries and we are currently in the process of the so called Polar Shift. How likely would it be ...
9
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1answer
3k 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, ...
6
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1answer
234 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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1answer
59 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 ...
3
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1answer
5k 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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1answer
271 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 ...