How strong (magnitude-wise) does an earthquake have to be for you to feel it?
457880
About a 3.0...and I live in California so I know.
734176
Earthquakes, I guess I'm kind of used to it. I live in L.A.
1070241
A seismograph measures the strength and direction of earthquake waves. It records the tremors and compares their strengths on the Richter scale. A scale of one is a minor earthquake, while a scale of seven is severe.
142973
Yeah, like the guy above me said. More elequently, it's not knowing WHERE they are going to go, but WHEN.\n\nIt is virtually impossible to tell exactly when sudden displacement along a fault will occur, although the fact that it will eventually occur can be predicted. This is done by comparing the displacement of regions along the fault that move regularly (and without violent earthquakes) to quiet regions that are not experiencing any little quakes. It's the quiet regions that are to be worried about. They just sit and build up elastic potential and then snap all at once without warning.\n\nRule of thumb, do not live along active fault zones, nor on top of any tsunamite deposits (can be recognized by large angular blocks deposited in a diamicton).
946669
Earthquakes 10.5 are impossibly big.  Places in America where you get earthquakes as big as 9 only happen along the coast of Alaska.  The biggest earthquake that can happen on the San Andreas is about 8.  Volcanoes in the US are only related to some faults, not all, and they are not interconnected, so one eruption is not related to nor does it cause another.\n\nHere are some basics on earthquakes/volcanism to help you with why this is physically impossible:\n\nEarthquakes: \nIt all comes down to stress and strain from the interaction of different plates, chiefly at the boundaries. It is not 'the plates rubbing together' as many people say; or at least that's a very simplistic view.\n\nPlate tectonics causes stress on the continents and oceans, all over the surface of the earth. In some places, the stress is very small (usually within the plates). Elsewhere, the stress is high, usually where the plates meet each other. Since each plate moves, when two come in contact, the stress each other. They can push on each other and cause compressional stress, they can pull with extensional stress, and they can slide past or shear each other with tensional stress.\n\nFaulting, causing earthquakes, comes from the fact that this stress is building up all the time, but rocks and continents are strong materials. Just like hitting a rock with a small hammer, you do put stress on it, but a small amount. It would take a sledgehammer to put enough strain (effects and accumulation of stress) to build up and cause breakage. In the earth, the area around an active fault builds up strain from the stress of plate tectonics. Most faults become locked, because of this strength, and thus can not release their strain. Away from the fault, the stress produces very small and slow movement of the rock masses as a whole. Eventually, the strain is too much and the rest of the plate has moved too far and the fault releases the strain build-up all at once in a big stress release called an earthquake. This is called the elastic rebound theory, and it explains most (but not all) movements.\n\nThis is why an earthquake's size is relative to the fault size. The bigger the fault, the bigger the strain build up, and the bigger the release in an earthquake. Subduction zones and collision zones, where large portions of plates actually can rub together as a whole, have the really big earthquakes, like the 2004 Sumatra earthquake. In other plate boundaries, the entire plate boundary does not act together, so the faults become spread out and many faults take up the strain from the tectonic stress, like with the San Andreas Fault in California (it only takes up ~3/4 of the stress between the plates).\n\nEarthquakes are really tricky things; there is still so much we need to learn. As of now, there is no way to predict them, but we can say where the danger is highest and about how long between events.\n\nVolcanoes:\nThere are several processes in Plate Tectonics that cause volcanism, but they result in two main types of volcanism.\n\nVolcanism in subduction is caused by volitals, like H2O, CO2. These are carried down by the plate, mainly in the form of weak minerals. These minerals break down with pressure and temperature into stronger minerals that don't contain water and carbon dioxide. The leftover gases and liquids travel into the mantle (the mantle wedge) and hydrate the mantle, causing melting. The melt rises and then... volcano!\n\nThe other main cause is from rising mantle material, which forms decompression melting. Basically, hot mantle is kept from melting by the pressure of the earth at depth. When this material rises, the pressure drops much faster than the temperature, and thus it partially melts. This mainly occurs at divergent boundaries and hot spots, which are areas in plate tectonics that have rising materials or spreading.
74742
You can not tell how .... but you can feel it!\nAction speak louder than words!!!
231177
Is this a project that requires you to build or write something about earthquakes?\n\nI would suggest building different types of structures (buildings) to see how each would withstand a quake. The only problem with that is you would have to have a way of testing the structures. You can actually use a board underneath the structures & just move the board back & forth.\n\nYou could make a homemade siesmograph machine. Doesn't take much. Look it up on the net.
752488
Here are the statistics on magnitude of earthquakes, and the number of quakes at each magnitudes, annually.  These records are averages since the year 1900.\n\nGreat, 8 and higher: 1\nMajor,  7 - 7.9:  17\nStrong,  6 - 6.9:  134\nModerate,  5 - 5.9:  1319\nLight,  4 - 4.9:  13,000\nMinor,  3 - 3.9:  130,000\nVery Minor,  2 - 2.9:  1,300,000
370880
Extremely unlikely. I've never heard of any man made earthquakes.
553608
The moment magnitude scale was introduced in 1979 by Tom Hanks and Hiroo Kanamori as a successor to the Richter scale and is used by seismologists to compare the energy released by earthquakes. The moment magnitude Mw is a dimensionless number defined by\n\n \nwhere M0 is the seismic moment.\n\nAn increase of 1 step on this logarithmic scale corresponds to a 101.5 = 31.6 times increase in the amount of energy released, and an increase of 2 steps corresponds to a 103 = 1000 times increase in energy.\n\nThe constants in the equation are chosen so that estimates of moment magnitude roughly agree with estimates using other scales such as the Richter magnitude scale. One advantage of the moment magnitude scale is that, unlike other magnitude scales, it does not saturate at the upper end. That is, there is no particular value beyond which all large earthquakes have about the same magnitude. For this reason, moment magnitude is now the most often used estimate of large earthquake magnitudes. The USGS does not use this scale for earthquakes with a magnitude of less than 3.5.
746545
There are earthquakes all the time.  Do you mean a destructive one?  That would be the quake that interrupted a game during the 1989 World Series when the Giants were playing at home.  Do you mean one some people just barely felt or noticed?  Earlier this month.  Do you mean one detected only by seismograph?  Probably within the last fifteen minutes.\nThe San Andreas fault runs right through San Francisco Bay, and there are plenty of other active faults in the area.
12689
the largest earthquake in the states was about an 8.3. the epicenter was near new madrid, missouri. it hit in 1812... before the richter scale was invented, so we aren't 100% sure what it would measure on that scale.\n\nthe two aftershocks were more destructive than the original quake, though they were not as strong.
1181105
I lived in L.A. for twenty years - and I'd rather be in an earthquake.  Most of them don't do much damage, they're over quickly enough and aftershocks are rarely bigger than the original quake.  For the most part, people know what to do when the Earth starts to move, and there often aren't any fatalities or even injuries.\n\nYou might be able to get away from a hurricane because you have warning, but overall the damage is much more severe and all encompassing than an earthquake, and because you've left, you don't always know what's going on with your home.\n\nI'd take my chances with an earthquake, thanks.
401627
As a pilot and a Geologist, I find this highly unlikely.  \n\nThe first consideration is the media through which the wave are transferred.  Consider this simple experiment.  If you wave your hand through the air, the wind generated wouldn't be felt by someone on the other side of the room.  Air is a terrible transmitter of vibrations.  It tends to dampen most vibration.  Now consider that the plane was several miles in the air, it seems highly unlikely that the plane would have felt the effects of the quake.\n\nSecondly, Geologically speaking, earthquake waves tend to radiate out from an epicenter and are likely never felt at the point exactly opposite the epicenter on the earth's surface.  The Iron-Nickel core dampens the shock waves of the quake to the point where waves simply never appear on the opposite side of the earth.\n\nThird, there are no alarm signals in a plane to indicate that the earth is shifting.  \n\nFourth, the plane was landing to make a refueling stop, and so was low on fuel already.  Most sources point to a running out of fuel or fuel system malfunction as teh likely cause of the accident.  \n\nFifth, the article to which you refer first appeared in the Russian equivalent of the National Enquirer or Weekly World News (Grocery Store Scandal Magazines).\n\nThus, when flying there is little to fear from the quaking earth below you.  In fact, you're probably safer where you are.
336125
It is 1000 times stronger. The richter scale is an exponential scale. So from 1 to 2 is 10 times worse.
91370
It's definitely a scary experience.  Let me share a short story with you...\n\nI used to live in California.  Growing up in Cali allowed me to go through numerous earthquakes of varying degree.  When my sister and I were younger, she used to FREAK OUT when one would strike.  I was scared too, but had to be strong for the both of us.  When she got married, she and her husband experienced a 4.1 earthquake together.  He had never felt one before so when this earthquake hit, he FREAKED out and guess what?  My sister was strong for him!  That's how she overcame earthquakes.  My recommendation to you is: BE STRONG.  STAY CALM.  Find a safe spot to keep away from falling debris.\n\nGod Bless!
225628
yes you can detect an earthquake. there are all kinds of instruments to help you.