Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Small Earthquakes

Skip navigational links
Dictionaries: Our Mapping Systems   The USGS and Science Education   USGS Fact Sheets   Topics   Keywords   Data Dictionary   Metadata Dictionary   Computer Terminology   Digital Formats  
InfoBank Terms: Activity ID   activity overview   crew   digital data   formal metadata   lines   metadata   NGDC   port stops   project/theme   region   ship   stations   time   virtual globe   year  
Data Types: bathymetry   biological   geochemical   gravity   ground penetrating radar   imaging   LIDAR   logs   magnetics   metering equipment   navigation   samples   seismic   total station   definitions disclaimer  
Data Formats: ARC coverage   E00   FGDC metadata   gridded/image   imaging   material   scattered/swath   Shapefile   vector/polygon  
Comment: 23:17 - 24:30 (01:13)
Source: Annenberg/CPB Resources - Earth Revealed - 9. Earthquakes
Keywords: earthquake, "Cathleen Aviles", fault, magnitude, "fault zone"

Our transcription: Tiny earthquakes are common occurrences along most active faults, but shortly before a large quake, the frequency and distribution of small shocks may change.
Being the person who looks at the seismicity, I'm expecting to see some changes in the patterns of the earthquake.
The earthquakes occur in the fault zone in a fairly complicated manner.
Some places the activity's shallow; some places the activity's deep.
As we get more detailed information about the fault zone, we see certain knots or clusters that are active.
What we're seeing, what we're expecting to see is that the larger earthquakes will start at magnitude 2's, 2.5's, 3's, and they'll start migrating down the fault zone towards the area that will fail first in that earthquake.
This is the pattern that's been seen in '34 and in '66 and that we're keeping a very close eye on the activity to see if that kind of activity occurs again.

Geology School Keywords
Skip footer navigational links

Coastal and Marine Science Centers:  Pacific   St. Petersburg   Woods Hole  
InfoBank   Coastal and Marine Geology Program   Geologic Information   Ask-A-Geologist   USGS Disclaimer  

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:26:07 PDT 2013  (chd)