The number of earthquake-related fatalities across the world was much higher in 2008 than in recent years.
About 88,070 deaths resulted from earthquake activity worldwide during 2008, according to the U.S. Geological Survey (USGS) and confirmed by the United Nations Office for Coordination of Humanitarian Affairs (OCHA). This is the largest number of deaths from earthquakes in a year since 2004.
The strongest and most destructive earthquake of 2008 occurred in Eastern Sichuan, China on May 12, claiming at least 69,185 lives. This 7.9 magnitude earthquake injured 374,171 people, while a further 18,467 remain missing and are presumed dead in the Chengdu-Lixian-Guangyuan area. More than 45.5 million people-a total greater than the combined populations of California, Arizona and Nevada-were affected by this earthquake, which struck in one of China's most densely-populated regions. The event also triggered many landslides, some of which buried large sections of some towns including Beichuan.
In addition to China, earthquakes killed people in 13 countries on 4 continents during the past year, including Algeria, Colombia, Democratic Republic of the Congo, Greece, India, Indonesia, Iran, Japan, Kyrgyzstan, Pakistan, Peru, Russia, and Rwanda.
In the contiguous United States, the highest magnitude earthquake in 2008 occurred at 6.0 on Feb. 21 near Wells, Nevada. While no lives were lost as a result of this quake, at least three people were injured and more than 20 buildings were heavily damaged. As in most years, the strongest two earthquakes in the U.S. occurred in Alaska's Aleutian Islands. These two events struck on April 15 and May 1(note that these dates are the local date; because of the extreme western longitude of the Aleutian Islands, the earthquakes occurred on April 16 and May 2 under Coordinated Universal Time (UTC)). The magnitude of both earthquakes was 6.6, but because the Aleutians are so sparsely populated, neither earthquake caused any damage.
A magnitude 5.4 earthquake struck southeastern Illinois on April 18. Although it caused only slight damage to a few buildings at East Alton, Mount Carmel and West Salem, it was felt throughout the central U.S. including all or parts of Alabama, Arkansas, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North Carolina, Ohio, Tennessee, West Virginia and Wisconsin, as well as in southern Ontario, Canada. This event serves as a reminder that earthquakes can and do occur in eastern North America and that quakes in this area are felt over a much larger area than they are in California.
The USGS estimates that several million earthquakes occur throughout the world each year, although most go undetected because they hit remote areas or have very small magnitudes. The USGS National Earthquake Information Center (NEIC) locates about 50 earthquakes per day, or about 20,000 annually. On average, only 18 of these earthquakes occur at a magnitude of 7 or higher each year.
In 2008, only 12 earthquakes reached a magnitude of 7.0 or higher, and no earthquake broke a magnitude of 8.0. These statistics are lower than those of 2007, which experienced 18 earthquakes over magnitude 7.0, but significantly fewer deaths.
Factors such as location and depth of the earthquake, the population density, and stability of infrastructure such as buildings and roads all influence how earthquakes will affect nearby communities. As can be seen from the earthquakes this year in the U.S., a magnitude 6.6 in the Aleutian Islands caused no damage and was felt by a few people on the island of Adak, whereas a much smaller 5.4 earthquake in Illinois was felt across 18 states.
A complete list of 2008 earthquake statistics can be found at the Earthquake Hazards Program: Earthquake Information for 2008 Web site.
To monitor earthquakes worldwide, the USGS NEIC receives data in real-time from nearly 400 stations in 85 countries, including the 150-station Global Seismographic Network, which is jointly supported by USGS and the National Science Foundation and operated by USGS in partnership with the Incorporated Research Institutions for Seismology (IRIS) consortium of universities.
In the U.S., earthquakes pose significant risk to 75 million people in 40 states. The USGS and its partners in the multi-agency National Earthquake Hazard Reduction Program are working to improve earthquake monitoring and reporting capabilities via the USGS Advanced National Seismic System (ANSS). More information about ANSS can be found at the ANSS - Advanced National Seismic System Web site.