Earthquakes today

Current and latest world earthquakes breaking news, activity and articles today

Geological news

USGS Director Welcomes Independent Panel Report Confirming that Scientific Basis for New Madrid Seismic Hazard is Sound

USGS Director Welcomes Independent Panel Report Confirming that Scientific Basis for New Madrid Seismic Hazard is Sound

The National Earthquake Prediction Evaluation Council has issued a new report in which independent experts conclude that current USGS estimates for significant earthquake hazards in the New Madrid Seismic Zone—affecting eight central and eastern U.S states—are based on sound science.

The Council, a federal advisory committee, recently presented the report to USGS Director Marcia McNutt.  Prepared by a panel of scientists from many disciplines and organizations, the report comes during the Bicentennial commemoration of the three violent “New Madrid” earthquakes and hundreds of aftershocks that struck the Mississippi River Valley in 1811-1812. 

“I commend NEPEC for assembling an independent expert panel to weigh scientific evidence regarding the threat posed by large earthquakes in the New Madrid Seismic Zone,” said Director McNutt. “This is an important issue that has spurred decades of excellent research on the large earthquakes of 1811 and 1812; the geologic evidence of similar earthquakes in previous centuries; and how our modern cities and towns would be shaken if similar earthquakes were to occur today.” 

Professor John Vidale of the University of Washington chaired the independent panel of experts, who concluded in the report that:

  • The New Madrid Seismic Zone represents a significant hazard for large earthquakes that would cause widespread damage.
  • This hazard must be accounted for in urban planning and development.
  • The panel does not support the view of some individuals that the region has “shut down” in its production of large earthquakes.
  • The current version of the USGS national seismic hazard maps are a good estimate of the overall hazard posed by the New Madrid Seismic Zone and should continue to be used until the next revision of the maps replace them in 2013.
  • Additional research could lower remaining uncertainties and thus potentially lower the potential hazard in future maps. 

The New Madrid Seismic Zone overlaps eight states: Alabama, Kentucky, Mississippi, Tennessee, Illinois, Indiana, Arkansas and Missouri.  It is the most seismically active area of the United States east of the Rockies. Scientists are pursuing research on numerous aspects of the hazard; this work has shown that there have been several sequences of big earthquakes during at least the past several thousand years. Because earthquakes in the central and eastern U.S. are more infrequent than in the western U.S., there are fewer observations and therefore greater uncertainties about future hazards. 

During the bicentennial anniversary of the earthquakes, scientists and emergency managers are raising awareness of earthquake hazards and providing information to help communities take steps to lessen the impacts of future earthquakes. 

NEPEC was congressionally established in legislation authorizing the four-agency National Earthquake Hazards Reduction Program. The Council provides advice and recommendations to the USGS Director on earthquake predictions and related scientific research.

The report and an accompanying letter from NEPEC Chairman Terry Tullis are posted on the Council’s website.  More information on earthquake hazards can be found on the USGS website.

USGS Newsroom

More information

Parameter Value Description
Magnitude mb The magnitude for the event.
Longitude ° East Decimal degrees longitude. Negative values for western longitudes.
Latitude ° North Decimal degrees latitude. Negative values for southern latitudes.
Depth km Depth of the event in kilometers.
Place Textual description of named geographic region near to the event. This may be a city name, or a Flinn-Engdahl Region name.
Time 1970-01-01 00:00:00 Time when the event occurred. UTC/GMT
Updated 1970-01-01 00:00:00 Time when the event was most recently updated. UTC/GMT
Timezone offset Timezone offset from UTC in minutes at the event epicenter.
Felt The total number of felt reports
CDI The maximum reported intensity for the event.
MMI The maximum estimated instrumental intensity for the event.
Alert Level The alert level from the PAGER earthquake impact scale. Green, Yellow, Orange or Red.
Review Status Indicates whether the event has been reviewed by a human.
Tsunami This flag is set to "1" for large events in oceanic regions and "0" otherwise. The existence or value of this flag does not indicate if a tsunami actually did or will exist.
SIG A number describing how significant the event is. Larger numbers indicate a more significant event.
Network The ID of a data contributor. Identifies the network considered to be the preferred source of information for this event.
Sources A comma-separated list of network contributors.
Number of Stations Used The total number of Number of seismic stations which reported P- and S-arrival times for this earthquake.
Horizontal Distance Horizontal distance from the epicenter to the nearest station (in degrees).
Root Mean Square sec The root-mean-square (RMS) travel time residual, in sec, using all weights.
Azimuthal Gap The largest azimuthal gap between azimuthally adjacent stations (in degrees).
Magnitude Type The method or algorithm used to calculate the preferred magnitude for the event.
Event Type Type of seismic event.
Event ID Id of event.
Event Code An identifying code assigned by, and unique from, the corresponding source for the event.
Event IDS A comma-separated list of event ids that are associated to an event.

Leave a Reply