Earthquakes today

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


Geological news

No Evidence for Large Triggered Earthquakes Across the Globe



No Evidence for Large Triggered Earthquakes Across the Globe

MENLO PARK, Calif. — New scientific research concludes that large earthquakes do not increase the global seismic hazard for more damaging earthquakes far from the mainshock. Although large aftershocks close to the mainshock remain highly probable following an earthquake, and small earthquakes less than magnitude 5 can be triggered at great distances, scientists at the U.S. Geological Survey and the University of Texas at El Paso found no significant increase in the rate of large earthquakes happening farther away than two to three times the length of the ruptured fault that caused the mainshock. 

“Based on the evidence we’ve seen in our research, we don’t think that large, global earthquake clusters are anything more than coincidence,” says Tom Parsons, USGS geophysicist and author of the new study that appears in this month’s journal, “Nature Geoscience.” 

The study looked at all M5 or greater earthquakes worldwide potentially associated with a M7 or greater event over the past 30 years. Using these data, scientists compared the timing of seismic wave arrivals and the occurrence of large earthquakes worldwide and found no correlation. 

The study, “Absence of remotely triggered large earthquakes beyond the mainshock region,” appears in a current edition of “Nature Geoscience.” The research was conducted by Tom Parsons, U.S. Geological Survey and Aaron A. Velasco, University of Texas, El Paso.

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