What is Earthquake: Definition and 164 Discussions
An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to propel objects and people into the air, and wreak destruction across entire cities. The seismicity, or seismic activity, of an area is the frequency, type, and size of earthquakes experienced over a period of time. The word tremor is also used for non-earthquake seismic rumbling.
At the Earth's surface, earthquakes manifest themselves by shaking and displacing or disrupting the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides and occasionally, volcanic activity.
In its most general sense, the word earthquake is used to describe any seismic event—whether natural or caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its hypocenter or focus. The epicenter is the point at ground level directly above the hypocenter.
5.8 in Virginia
http://www.google.com/search?client=opera&rls=en&q=recent+earthquakes&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest
According to Wikipedia, this is the strongest earthquake since a similarly sized one in 1897...
Well i am researching on seismology and tectonic plates. My project hypothesis is related to reducing the magnitude of P-S-L waves that are generated when tectonic plates collide,create subduction zones etc.
for the project i have a choice of submitting a theoretical or real model.my query is...
This came out in May. I just saw it.
http://arxiv.org/abs/1105.2841
There were interesting signals in the atmosphere that peaked just 3 days before the earthquake struck.
Apparently the deep rock layers around the fault show they are stressed by releasing radon gas, which has a detectable...
Homework Statement
Earthquakes produce several types of shock waves. The best known are the P-waves (P for primary or pressure) and the S-waves (S for secondary or shear). In the Earth's crust, P-waves travel at around 6.40 km/s while S-waves move at about 3.60 km/s. (The actual speeds vary...
Is it possible to "create" an earthquake?
Hypothetically if you buried and detonated a dozen or a hundred nukes along an active fault line, like the San Andreas, would the release of that much energy cause a major earthquake along that faultline?
How crazy is this?
Continued...
This is beyond absurd.
http://news.yahoo.com/s/livescience/20110526/sc_livescience/seismologiststriedformanslaughterfornotpredictingearthquake
The french IRSN just released a new report concerning the estimated contamination around DAICHI, i extract this map for the Cs contamination based on SPEEDI/MEXT estimations. The complete report is here (french)...
On the Japanese Earthquake: Nuclear Plants thread in PF Nuclear Engineering forum we have been having a lot of trouble figuring out descriptions of mudstone and plant foundations built on solid bedrock. Can anyone help me on this.
I followed some research clues and found the following:
A...
The "more political thread" besides "Japan Earthquake: nuclear plants" scientific one
As agreed with PF Mentor Borek, i start this new thread which intends to be a complement to the big and permanently updated "Japan Earthquake: nuclear plants" thread (which started here...
With everything that's going on at Fukushima, I'm wondering how a newer reactor (Generation III or newer) would have held up under the same conditions?
I understand it's near impossible to tell from anything this catastrophic and unprecedented, but perhaps Astronuc or someone else more...
Supposedly, you use a certain type of seismometer. But in that case, how could a deep earthquake far away register as "higher" than a shallow earthquake that's up close? Sure, the deep earthquake may release more energy, but much of it is dissipated by the time it reaches the seismometer (and...
http://www.youtube.com/user/citizentube#grid/user/0870831CE43351E1
http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/c0001xgp/
Yes, it was the most powerful Japanese earthquake in terms of the amount energy released. But the youtube videos show that the shaking wasn't even that...
Does anyone have any reliable info on the nuclear plants - the reports on the news seem garbled to me.
Edit by Borek:
To All:
Please stick to technical aspects and to things happening at the Fukushima Daiichi NPP.
There are several other threads discussing different aspects of the...
Homework Statement
When an earthquake occurs, two types of sound waves are generated and travel through the earth. The primary, or P, wave has a speed of about 7.87 km/s and the secondary, or S, wave has a speed of about 4.86 km/s. A seismograph, located some distance away, records the arrival...
The elections for a new parliament have caused remarkable shifts in political Netherlands. It's all recorded here already (tentatively - it's not formal yet). Note the big plusses and minusses. A sharp right turn was made.
Basically the moderate center (CDA) has suffered, while the liberals...
Just in (6:35 EDT, it's now 6:49), few details yet.
Epicenter: 2.236°N, 97.046°E (Next to an island, just off the coast)
Depth: 46 km
CNN: http://news.blogs.cnn.com/2010/04/06/usgs-earthquake-strikes-northern-sumatra/?hpt=T2
USGS...
I was down at the cafe where I hang out this afternoon while a clever person of my acquaintance was at work fixing my laptop, when the table started doing a rock and roll dance. I thought at first he was pushing on it and he thought I was doing it. Suddenly we both realized it was an earthquake...
The project entails the design and simulation of a system to stabilize a building in the event of an earthquake. The idea is to numerically test the response of the system to earthquake conditions and see how it performs. It will also involve varying the relevant parameters to obtain the most...
Homework Statement
Assume that P and S (Primary and Secondary) waves from an earthquake with a focus near the Earth's surface travel through the Earth at nearly constant but different average speeds. A monitoring station that is 1000 km from the epicenter detected the S wave to arrive at 42...
This is just a question that has been bugging me for awhile, but, in a worst-case scenario, if you say had an earthquake where the ground split open, and a nuclear plant was right over the split, could the reactor literally be "ripped open" in such an instance? And if so, would this cause the...
http://www.newsdaily.com/stories/tre53504a-us-quake-italy/
ROME, Apr. 5, 2009 (Reuters) — A 6.7 magnitude earthquake struck central Italy Monday about 53 miles northeast of Rome, the U.S. Geological Survey reported.
I have a question regarding the production of an effect similar to that of an earthquake.
Let's presume that it's in a large area. It's moving. Like, for example, a train.
If a force where to applied in a single point, of the size of a tennis ball, would it be possible to cause the...
I have heard people talk about "earthquake weather" and we had weird weather today. Hazy and very hot with warm winds. The weather website said it was 90 degrees F at sundown.
This was copied from another thread where Math Is Hard experienced an earthquake while making a post - Ivan...
Homework Statement
4people with uniform mass= 72.4kg
car mass= 1130kg
earthquake strikes,car is stationary.
vertical oscillations make car bonuce on suspensions.
when frequency= 1.8 Hz car exhibits maximum Amplitude of vibration.
Earthquake over,4 people leave the car quickly,what...
Hi everyone, I live in Chengdu, China where as many of you may know suffers a terrible earthquake aftershock nowadays. But during every aftershock there's always a wind blowing from nowhere. I wonder why? Many of my classmates & friends notice this as well. Are there any scientific explanations?
Earthquake! in Illinois!
Earthquake rattles Tri-State
http://www.courierpress.com/news/2008/apr/18/earthquake-rattles-tri-state/
I woke up to a noise--looked at the clock 4:35--like the wind rattling the window--but it was one of the paintings on the wall rattling against the wall...
http://news.bbc.co.uk/1/hi/england/7266136.stm
Wow, that was about 30 miles from my house. No damage, but certainly a shock to wake up to. Did anyone else feel it?
[SOLVED] Distance To Center of Earthquake?
Homework Statement
An earthquake releases two types of traveling waves, called "traverse" and "longitudinal." The average speed of traverse and longitudinal seismic waves in rock are 8.9 km/s and 5.1 km/s respectively. A seismograph records the...
Homework Statement
Assuming typical speeds of 8.9 km/s and 5.8 km/s for P and S waves, respectively, how far away did the earthquake occur if a particular seismic station detects the arrival of these two types of waves 1.0 min apart?
_____km
Homework Equations
v=(lamba)(f)...
[SOLVED] Simple Harmonic Motion
Homework Statement
Four people, each with mass of 71.1 kg, are in a car with a mass of 1180 kg. An earthquake strikes. The vertical oscillations of the ground surface make the car bounce up and down on its suspension springs, but the driver manages to pull of...
As a resident of the San Francisco Bay Area, the recent quake got me thinking - how prepared are the buildings and structures in the Bay Area for the upcoming 'Big One'? I mean, are the majority of buildings, bridges, and tunnels capable of handling a magnitude 7 or 8 quake?
Also, what about...
Homework Statement
Earthquakes produce several types of shock waves. The most well known are the P-waves (primary or pressure) and the S-waves (secondary or shear). In the Earth's crust, the P-waves travel at around 6.5km/s, while the S-waves move at about 3.5km/s. The actual speeds vary...
I have to just throw this one out and see what comes. I have no idea if this is credible, but there are claims that local news agencies in Peru are reporting that earthquake lights were seen before and after the recent quake. There are a couple of videos included in the report...
When an earthquake occurs, two types of sound waves are generated and travel through the earth. The primary, or P, wave has a speed of about 8.0 km/s and the secondary, or S, wave has a speed of about 4.5 km/s. A seismograph, located some distance away, records the arrival of the P wave and...
3.9 (Minor) - 4 miles (7 km) SSE (157°) from Bar Harbor, ME - Minor yes, but strong enough to send boulders rolling off hills and blocking roads. Bar Harbor is a small populated area.
Tuesday, October 3, 2006 at 00:07:37 (UTC) = Coordinated Universal Time
Monday, October 2, 2006 at...
WOW! - a strong earthquake in the Gulf of Mexico! That is rather rare!
6.0 (Strong) - http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/usslav.php
Sunday, September 10, 2006 at 14:56:07 (UTC) = Coordinated Universal Time
Sunday, September 10, 2006 at 8:56:07 AM = local time at...
http://www.nytimes.com/2006/08/08/science/08find.html?ex=1312689600&en=86a5d1a41980f607&ei=5090&partner=rssuserland&emc=rss"
How is it possible to have a drop in gravity when a Earth quake happens?
This worls is divided into two groups(not obviously boys and girls:biggrin: ),,first one who believe dams cause earthquakes and second one dam prevent earthquake..
you are in which one and what's your reasoning..
This can use some more visibility. Our press seems more interested in Wilma, which is weakening, than in the earthquake, whose death toll continues to mount.:grumpy: The toll has jumped from 54,000 to 79,000 this week aone, and may double if we don't get more aid to the region...
There was a 7.6 magnitude earthquake early this morning in Pakistan. I was getting ready to sleep, around 9 am, when it hit Lahore...See, we were sleeping in the common room which has AC (our individual rooms don't have AC)...It was me, my roomie, and 3 other people sleeping there. We were...
By CHRISTOPHER TORCHIA, Associated Press Writer
http://news.yahoo.com/s/ap/20051008/ap_on_re_as/pakistan_quake
We have a number of members in Pakistan and India. I hope all are OK.
http://en.wikipedia.org/wiki/2005_Indian_subcontinent_earthquake