Earthquakes – A National Threat
Earthquakes are one of the most costly natural hazards faced by the Nation, posing a significant risk to 75 million Americans in 39 States.
The risks that earthquakes pose to society, including death, injury, and economic loss, can be greatly reduced by (1) better planning, construction, and mitigation practices before earthquakes happen and (2) providing critical and timely information to improve response after they occur.
As part of the multiagency National Earthquake Hazards Reduction Program, the U.S. Geological Survey (USGS) has the lead Federal responsibility to provide notification of earthquakes in order to enhance public safety and to reduce losses through effective forecasts based on the best possible scientific information.
Science Helps Prepare the Nation The USGS supports regional, national, and global seismic-monitoring networks, studies why earthquakes occur and how they shake the ground, assesses the hazard level across the Nation, promotes loss-reduction measures using these results, and provides crucial scientific
information to help emergency responders when earthquakes occur.
The USGS is gathering data for expanded urban hazard assessments on a local scale to understand how varying soil conditions affect the shaking and damage within cities and at critical lifelines. The USGS is also conducting research to better understand how these hazards change with time.
Although earthquakes occur less frequently in the Eastern United States, studies show that urban areas in the East could face devastating losses because severe shaking would affect a larger area than a similar earthquake in the Western United States. Also, most structures in the Eastern United States are not designed to resist earthquakes.
Population density is also high in the Eastern United States, and residents are not as well prepared for earthquakes as communities in the West.
In Alaska and the Pacific Northwest, the effects of a destructive earthquake can extend well beyond local impact by potentially creating far-reaching tsunamis and resulting in economic losses that could exceed any that have occurred from previous earthquakes or tsunamis.
The USGS Is Networking
The USGS and university and State Geological Survey partners have begun to install and operate the Advanced National Seismic System (ANSS), a national network of sophisticated shaking monitors placed both on the ground and in buildings in urban areas.
ANSS stations will provide better data crucial for finding cost-effective seismicdesign solutions for homes, buildings, bridges, and other structures.
In cities where ANSS is in place, such as Los Angeles, the USGS has begun producing maps within minutes of an earthquake showing the distribution and severity of ground shaking in or near the urban center. These “ShakeMaps” form the basis for emergency response by cities, States, Federal agencies, and critical lifeline operators.
The USGS will continue to improve on existing earthquake monitoring, assessment, and research activities, with the ultimate goal of providing new products that facilitate more effective mitigation and response.
Information courtesy of the U.S. Geological Survey