The Northridge earthquake occurred at 4:30 a.m. local time on January 17, 1994.This earthquake had a 6.9 magnitude.The Northridge earthquake was the worst earthquake in the Los Angeles area since the San Fernando earthquake in 1971, which had a 6.7 magnitude. 57 people in because of this earkquake and about 9000 people were injured.
The official death toll from Japan's devastating earthquake and tsunami passed the 10,000 mark Friday and was still 660,000 households do not have water more than 209,000 do not have electricity. Damage could rise as high as $310 billion, the government said, making it the most costly natural disaster on record.
Seismic waves are waves of energy that travel through the earth, for example as a result of an earthquakes explosion, or some other process that imparts low-frequency acoustic energy.Earthquakes create various types of waves with different velocities; when reaching seismic observatories, their different travel time enables the scientists to locate the epicenter.Seismic waves are divided into two types: Body waves and surface waves. Body waves include P and S waves, and these are the two types of waves that are used to determine the internal structure of the Earth
