What is a seismic zone, or seismic hazard zone?
Although you may hear the terms “seismic zone” and “seismic hazard zone” used interchangeably, they really describe two slightly different things. A seismic zone is used to describe an area where earthquakes tend to focus; for example, the New Madrid Seismic Zone in the Central United States. A seismic hazard zone describes an area with a particular level of hazard due to earthquakes. Typically, a high seismic hazard zone is nearest a seismic zone where there are more earthquakes, and a lower seismic hazard zone is farther away from a seismic zone.
Another point of confusion is that the California Geological Survey has two sets of maps with the names “Earthquake Hazards Zones” and “Earthquake Fault Zones (Alquist-Priolo)”.
There was also a seismic zone system (0,1,2,3,4) used for building codes that is now obsolete.
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USGS Authors New Report on Seismic Hazard, Risk, and Design for South America
New seismic hazard and risk assessments can help at-risk communities prepare for future earthquake disasters
New Audiences, New Products for the National Seismic Hazard Maps
New Audiences, New Products for the National Seismic Hazard Maps
Earthquake Hazard Maps Show How the Nation Shakes with Quakes
Friday's magnitude-5.2 earthquake in southern Illinois is a reminder that earthquakes are a national hazard.
New USGS Map Will Improve Earthquake Hazards Assessment in the Bay Area
A new geologic map of surficial deposits in the nine-county San Francisco Bay region that can be used to evaluate earthquake hazards has been released in digital form by the U.S. Geological Survey in Menlo Park.
USGS scientists conduct passive seismic study in the Washita Reach 1
USGS scientists conduct passive seismic study in the Washita Reach 1 study area.
Paleoseismic Investigations in Central VA Seismic Zone
HayWired Scenario ShakeMap
ShakeMap showing intensity of shaking for the HayWired Scenario.
See: http://earthquake.usgs.gov/earthquakes/shakemap/global/shake/haywiredm7....
San-Andreas Fault
Aerial photo of the San Andreas Fault in the Carrizo Plain. By Ikluft - Own work, GFDL, https://commons.wikimedia.org/w/index.php?curid=3106006
US map depicting earthquake loss by county
Figure 3-4
This map depicts annualized earthquake loss by county. The estimated losses consider the value of buildings in each specific area.
Map depicting difference in estimates of earthquake hazards 2002-2014
Figure 4-1
This map depicts the difference in USGS estimates of earthquake hazards across the nation in 2002 and 2014. The new FEMA earthquake loss report includes the 2014 data, while the previous 2008 report includes the 2002 data. The negative values represent a decrease in estimated hazard since 2002 and the positive values represent an increase.