Earthquakes
randall‚ IN | Earthquakes
why has there been so much recent low intensity earthquake activity in the region around puerto rico?
Meghan‚ MN | Earthquakes
Is there earth quakes going on in M.N. Right now???
nikky‚ CA | Earthquakes
Why are some places get more earthquakes more than others?
Haley‚ PA | Earthquakes
can you find a place where many earthquakes occur without volcanoes? is there a place where many volcanoes exist without earthquakes??
Veer‚ TX | Earthquakes
Why do earthquakes exist?
kwietstorm‚ NJ | Earthquakes
why do so many volcanoes occour along plate boundaries
steph | Earthquakes
how often do earthquakes occur along the san andreas fault line?
murryn‚ NC | Earthquakes
there was a 20 second earthquake in san fransico californa was a 8.1 or a7.9 earthquake it caused alot of damage.
Bilguun‚ HI | Earthquakes
Earthquakes are usually caused when rock underground suddenly breaks along a fault. This sudden release of energy causes the seismic waves that make the ground shake. When two blocks of rock or two plates are rubbing against each other‚ they stick a little. They don't just slide smoothly; the rocks catch on each other. The rocks are still pushing against each other‚ but not moving. After a while‚ the rocks break because of all the pressure that's built up. When the rocks break‚ the earthquake occurs. During the earthquake and afterward‚ the plates or blocks of rock start moving‚ and they continue to move until they get stuck again. The spot underground where the rock breaks is called the focus of the earthquake. The place right above the focus (on top of the ground) is called the epicenter of the earthquake.
gdjklsa‚ HI | Earthquakes
why are there neer earthquakes in Maine?
DragonflyTV Expert: Don‚ CA | Earthquakes
Hi Rosalinda. As a rule earthquakes won\'t cause a volcano to be born unless conditions exist for a volcano to be born. When those conditions are there then it is more likely the volcano caused the quake. In the area of Lake Pillsbury in Northern California a volcano is being born now. At its current growth rate it will take 400‚000 years to reach the surface. We know this by the number of quakes that have been occurring in the area and the gases that have been detected at the surface as well as a temperature increase at the surface. A person walking on the surface in the area will not notice the temperature increase‚ but instruments designed to detect a temperature increase will. Another place where a volcano is being born is in the area of Three Sisters Volcano in Oregon. It is known as the "The Three Sisters Bulge". Gases known to exist with volcanoes has been detected at the surface and in some of the springs in the area. These gases are hydrogen sulfide‚ carbon dioxide and helium 3. Helium 3 is an isotope not found normally at the earth\'s surface unless fresh magma is rising towards the surface. The bulge along with the helium 3 is a very good indication that fresh magma is moving towards the surface. In 2003 a swarm of more then 1600 quakes occurred in the Lake Tahoe area. What was unusual about this swarm is that they occurred about 19 miles below the surface. It was also discovered that Slide Mountain rose almost 8 millimeters. This is a pretty good indication that fresh magma has been injected into the lower crust of the earth. Earthquakes caused by the movement of magma are called "long period quakes" or "harmonic tremors" and do not look the same on a seismograph as a tectonic quake. In essence it will be the volcano causing the earthquakes not the earthquakes causing the volcano.
stevie‚ CA | Earthquakes
hey bobby‚ I think i have an answer for your question when two tectonic plates collide it makes the earth shake and that can do real damage!
Rosalinda‚ CA | Earthquakes
Is it possible that an earthquake can creat avolcano and how is the prosses
Bobby‚ IL | Earthquakes
1 of the earthquakes in Tang Shan is the strongest earthquake in the world.
Bobby, IL | Earthquakes
How do earthquakes form
John, WA | Earthquakes
Earthquakes are so cool! Except for the fact that they can be seriously dangerous if it's like a 8.5 kind of earthquake (the kind that makes tall buildings fall!)
DragonflyTV Expert: Don, CA | Earthquakes
Hi JJ. North Carolina does get quakes. Its just that you haven\'t felt them as most of them are small. The largest quake felt in North Carolina didn\'t occur there. It was in South Carolina. The total area affected by this earthquake covered more than 5 million square kilometers and included distant points such as New York City, Boston, Milwaukee and Havana, Cuba, and Bermuda. All or parts of 30 states and Ontario, Canada, felt the principal earthquake.
In the Central and Eastern United States, earthquakes are felt over a broader area than comparable-size quakes in the Western United States because of differences in geology. The bedrock on the East Coast is much more solid then on the West Coast. We have many faults in the western part of the US and these are sort of like a cushion, or shock absorbers. However it is because of these faults that the West Coast has more quakes then the East Coast.
From NEIC:
"The most property damage in North Carolina ever attributed to an earthquake was caused by the August 31, 1886, Charleston, South Carolina, earthquake. Severe damage occurred in Charleston and in an area within a radius of 160 kilometers (100 miles). About 60 people were killed in the epicentral area. A number of places in North Carolina had chimneys thrown down, fallen plaster and cracked walls. These included Abbottsburg, Charlotte, Elizabethtown, Henderson, Hillsborough, Raleigh, Waynesville, and Whiteville."
"In 1957, two earthquakes, about 6 weeks apart, caused minor damage in separate areas of western North Carolina. The first shock, on May 13, resulted in cracked plaster at Micaville and Nebo (intensity VI). A sprinkler pipe was shaken loose in a factory at Woodlawn and books fell from school library shelves. The tremor was felt over an area of about 21,000 square kilometers, including a few places in South Carolina. The second shock, on July 2, 1957, caused a few cracked chimneys, cracked walls, and cracked plaster at Asheville, Marshall, Swannanoa, and Weaverville (intensity VI). This earthquake was felt strongly in Buncombe and Madison counties."
"A shock occurred on March 5, 1958, in the Wilmington area near the same place as the 1884 tremor previously mentioned. Many were awakened along the coast from Hampstead to Kure Beach and as far as 30 kilometers inland (intensity V). Press reports indicated that houses shook and some people were rolled out of bed."
"On December 13, 1969, a minor earthquake with a noise like a sonic boom awakened many at Glenville (intensity V). At Pickens, South Carolina, windows, doors, and dishes rattled slightly and many in the community were awakened. Moderate rumbling earth noises were heard. The shook affected an area of about 9,000 square kilometers in the two States. A similar earthquake occurred September 9, 1970, in the region around Boone. Slight damage from this shock was noted at Boone and Zionville (intensity V)Intensity V effects were also noted at Blowing Rock, Deep Gap, Newhope, Patterson, and Sugar Grove."
DragonflyTV Expert: Don, CA | Earthquakes
Hi Danni. Good question. Earthquakes are usually caused when rock underground suddenly breaks along a fault. When two blocks of rock or two plates are rubbing against each other, they stick a little. The rocks are still pushing against each other, but not moving. After a while, the rocks break because of all the pressure that's built up. When the rocks break, the earthquake occurs.
The longer any given area doesn\'t move the larger the quake will be. During the earthquake and afterward, the plates or blocks of rock start moving, and they continue to move until they get stuck again. It\'s a never ending cycle.
Most earthquakes occur along plate boundaries. In California the San Andreas fault is the boundary between the Pacific Plate and the North American Plate. The Pacific Plate is moving northwest and the North American Plate is moving southeast. The San Andreas fault is a little more then 800 miles long and cuts into the earth about 10 miles. The plates are always moving, except for some locations where the fault is stuck. Everything around the area that is stuck continues to move and eventfully the area that is stuck will move. If the plates didn\'t continue to move we wouldn\'t have earthquakes.
Aaron, BC | Earthquakes
i think space is amazing! especially mars!
jj, NC | Earthquakes
i never have them here
DragonflyTV Expert: Don, CA | Earthquakes
I have been studying earthquakes and faults for more then 40 years now and you may be surprised that we still don\'t know why we have big earthquakes. Every quake from the smallest one to the largest one to have ever occurred all starts the same way. A large earthquake is nothing more then a small quake that ran away. Why did that one quake run away? Better yet why did all of the other quakes stop? What stopped those little quakes from becoming big quakes? As most of you probably already know Parkfield, California finely had its quake. Scientists from around the World have been watching that town for more then 35 years. Every instrument known to be able to measure changes in the Earth\'s crust was there. Nothing was seen until 15 seconds before the quake occurred. There wasn\'t one single hint that an M=6.0 quake was about to occur. I checked the data sites about 4 hours before the quake occurred and didn\'t see anything that would signal that a quake was about to occur. There were all kinds of indications that a severe quake had just occurred, but that didn\'t tell us what we wanted to know.
Needless to say the residents of Parkfield (population 34) weren\'t too happy about the results of the experiment. Not one single glass at the Parkfield Café survived the quake. It didn\'t do the peoples nerves much good either. Most of them thought that at least this time they would get a warning. But like the quake of 1966 and 1934 it took them by surprise once again. The fault ruptured in the same place it did the previous two quakes except that this time it ruptured towards the north instead of towards the south like the other two did.
The picture is the bridge that crosses Little Cholame Creek. I\'m standing on the North American Plate looking west towards the Pacific Plate. The San Andreas Fault is just on the other side of the bridge. You can see the gentle twisting of the bridge to the right. This is because the Pacific Plate is moving northwest while the North American Plate is moving southeast. The San Andreas Fault is a right-lateral strike-slip fault, or transform fault. The land west of the fault formed in Southern California near Baja and has been moving northwest for a little less then 30 million years.
A lot of "chert" and "jasper" and well as some petrified wood can be found in this area. Not much in the volcanic activity can be found in this area, but about 60 miles north of Parkfield is a rock formation called "The Pinnacles" They are half of a volcano. The other half is near the Town of Lancaster, which is located in the Mojave Desert. Hope you enjoy...Don
Mike, NH | Earthquakes
Richard From NY, yes earthquakes do happen in england, more often than some people think possibly the last one i believe was september 2001
Ivy, NH | Earthquakes
Hi DFT!V I have a question. Why do earthquakes occour in some places more than others? Thanks!!!!!
danni, HI | Earthquakes
how do earthquakes start?
DragonflyTV Expert: Don, CA | Earthquakes
Hi. My name is Don and my home is in Hollister, California. We are known as the "creep capital of the World" because of the Calaveras Fault that runs through the town. I live about 3 blocks west of it and about 5 miles east of the San Andreas Fault.
I have been studying earthquakes and faults for more then 40 years now and they never cease to fascinate me. Most of the quakes occur along plate boundaries. As to why quakes occur in mid continents is not fully understood. This is mainly because we don\'t understand the workings of stress in the area. Without stress there would be no earthquakes, but we can\'t see where the stress is at, how much there is and how much it takes to cause a fault to fail. We can guess at it, but that is just about the extent of it. We can only guess. Take Care...Don
Here is a picture of a house that sits on the Calaveras fault here in Hollister. You can get a good idea as to how movement along the fault affects the surrounding area.
