FAQs

Qs. What is an earthquake

Ans. An earthquake occurs when rocks break and slip along a fault in the earth. Energy is released during an earthquake in several forms, including as movement along the fault, as heat, and as seismic waves that radiate out from the "source" and causes the ground to shake, sometimes hundreds of km's away. http://www.pgc.nrcan.gc.ca/seismo/eqinfo/q-a.htm#what_is_a_quake (Last access date 9 0ct 2005)

Qs. What causes earthquakes?

Ans. Earthquakes occur from the deformation of outer, brittle portions of "tectonic plates",the earth's outermost layer of crust and upper mantle. Due to the heating and cooling of the rock below these plates, the resulting convection causes the adjacently overlying plates to move, and, under great stresses, deform. The rates of plate movements range from about 2 to 12 centimeters per year. Sometimes, tremendous energy can build up within a single, or between neighbouring plates. If the accumulated stress exceeds the strength of the rocks making up these brittle zones, the rocks can break suddenly, releasing the stored energy as an earthquake. http://www.pgc.nrcan.gc.ca/seismo/eqinfo/q-a.htm#what_is_a_quake (Last access Date 9 Oct 2005)

Qs. Can earthquakes be predicted?

Ans. With the present state of scientific knowledge, it is not possible to predict earthquakes and certainly not possible to specify in advance their exact date, time and location. However, a great deal of research is being conducted to develop reliable prediction methods. Canada, along with other countries, is working to minimize damage and injuries through the implementation of modern earthquake-resistant standards sopeople will be protected whenever and wherever an earthquake occurs. http://www.pgc.nrcan.gc.ca/seismo/eqinfo/q-a.htm#what_is_a_quake (Last access Date 9 Oct 2005)

Qs. Does a local earthquake make another or a larger earthquake more likely?

Ans. Yes, for the next five days. But the chance is not high. Right after the earthquake, there is only about 6% chance of another earthquake that size or larger, and about 3% for an earthquake that is noticeably larger. The chance is decreasing all the time, and five days after the earthquake, it will be back essentially to normal. http://www.seismo.unr.edu/Perminfo/nevada.html#q10 (Last access Date 9 Oct 2005)

Qs. What is the biggest earthquake that has occurred historically?

Ans. An earthquake in Chile in 1960 broke a fault over one thousand miles long, and had a moment magnitude of 9.5.http://www.pnsn.org/INFO_GENERAL/faq.html#15 (Last access Date 9 Oct 2005)