Earthquakes today

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


Geological news

Unraveling Complexity of Haiti Quake Reveals Hidden Faults and Future Hazards



Unraveling Complexity of Haiti Quake Reveals Hidden Faults and Future Hazards

The January 2010 M7.0 earthquake that devastated Haiti’s economy and caused over 200,000 casualties also resulted in significant uplift of the ground surface along Haiti’s coastline, and involved slip on multiple faults, according to a study published online in Nature Geoscience.

Because the earthquake did not involve slip near the surface of the Earth, the study suggests that it did not release all of the strain that has built up on faults in the area over the past two centuries, and so future surface rupturing earthquakes in this region are likely.

The paper also suggests that similar events may be hidden from the prehistoric earthquake record both in Haiti and in other similar tectonic settings such as the San Andreas fault in California.

Gavin Hayes, a U.S. Geological Survey geophysicist, along with colleagues from USGS, California Institute of Technology, NASA’s Jet Propulsion Laboratory (JPL), and the University of Texas at Austin, used a combination of seismological observations, geologic field data and satellite geodetic measurements to analyze the earthquake source. Initially the Haiti earthquake was thought to be the consequence of movement along a single fault, which accommodates the motion between the Caribbean and North American plates.

By modeling the patterns of surface deformation, the team was able to assess which fault was responsible. Their results showed that the earthquake may not have been caused by the simple rupture of a single fault, but instead may have involved a complex series of faults.

The pattern of surface deformation was dominated by movement on a previously unknown, subsurface thrust fault, named the Léogâne fault, which did not rupture the surface.

Hayes, a post-doctoral researcher, is contracted to work for the USGS by Synergetics, Inc.

This is one of several papers to be published this month in a special issue of  Nature Geoscience on the Haiti earthquake.

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