The number of major earthquakes for 1999 is currently registering above normal, and quake-related casualties are double the annual average, according to U.S. Geological Survey (USGS) data. Earthquakes have caused more than 22,000 deaths worldwide since Jan. 1, 1999. More than 17,000 people were killed as a result of the magnitude 7.4 Izmit, Turkey, earthquake on August 17.
"Dense urban populations coupled with weak building structures along the epicenters are responsible for most fatalities," said Waverly Person, geophysicist with the USGS National Earthquake Information Center in Golden, Colo. The annual, long-term average is 10,000 deaths worldwide. In 1998, fatalities totaled 8,928, while 2,907 people were killed in 1997. The deadliest year in this century was 1976 when at least 255,000 people, and perhaps more than 600,000, were killed after one quake rocked Tianjin (formerly Tangshan), China.
A typical year for earthquakes consists of 18 major temblors (magnitude 7.0 to 7.9) and one great quake (8.0 or higher), according to the USGS. To date, no great quakes have occurred, but 20 major earthquakes shook the world in 1999. However, this figure is far below the 41 major and great earthquakes recorded in 1943.
Colombia felt the fatal effects early in 1999 when a magnitude 6.3 killed nearly 1,200 people on January 25. Turkey was the hardest hit, sustaining two major quakes -- the August 17 magnitude 7.4 and a magnitude 7.1 on November 12. Taiwan suffered a magnitude 7.6 on September 20, killing more than 2,400 people. Thus far, this is the largest quake on record for 1999.
The USGS estimates that several million earthquakes occur in the world each year. Many go undetected because they hit remote areas or have very small magnitudes. The USGS now locates about 50 earthquakes each day, totaling 20,000 a year. Real-time information about earthquakes can be found at http://www.neic.cr.usgs.gov/.
"Overall, earthquake activity isn't on the rise," said Person. "We're simply able to locate more lower magnitude earthquakes due to advances in the technology."
Since 1973, the USGS has provided up-to-date earthquake information to emergency response and mitigation teams, government agencies, universities, private companies, scientists and the general public. This information includes determinations of the locations and severity of seismic events in the United States and throughout the world, including the rapid analysis of significant earthquakes on a 24-hour basis. Seismologists around the world use this information to increase their understanding of earthquakes and to better evaluate earthquake hazards.
Materials provided by United States Geological Survey. Note: Content may be edited for style and length.
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