In 1989, a major earthquake devastated business and residential sections of San Francisco and the surrounding area, destroying a section of the Bay Bridge and an elevated freeway and killing over 75 people. California is earthquake country! The people of the major cities in our state do not ask if there will be another earthquake, they ask when and where it will happen. Although the major earthquakes have been in the San Francisco area so far this century, residents of Los Angeles must ask what the effects on the over 2 million people living in our urban area would be. It is time for the people of Los Angeles to make plans for "the big one.
Earthquakes generate seismic waves, which can be detected with a sensitive instrument called a seismograph. With the advances in seismograph technology it has helped us understand earthquakes and Earth itself. (A man named Choko invented the earliest seismograph in China in 136 A.D.) Earthquakes generate seismic waves, which can be detected with a sensitive as we have progressed thought the centuries we have developed improvements in technology, lives have been saved and many more will. All that remains is to research what takes place before, during, and after an earthquake. This has been done for years to the point now that a successful earthquake prediction was made and was accurate. With Earthquakes, the "vibrations produced in the earth's crust when rocks in which elastic strain has been building up suddenly rupture, and then rebound."(Associated Press 1993) The vibrations can range from barely noticeable to catastrophically destructive. Six kinds of shock waves are generated in the process. Two are classified as body waves-that is, they travel through the earth's interior-and the other four are surface waves.
Earthquake Design Benjamin Mullah Geology is the study of the earth's landmasses. The earth is constantly changing. These changes are to slow for one person to see in his or her lifetime.
