Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Alignment Array Surveys

Skip navigational links
Loading
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: 19:49 - 21:02 (01:13)
Source: Annenberg/CPB Resources - Earth Revealed - 9. Earthquakes
Keywords: "alignment array", "fault slip", "Robert O. Burford", "San Andreas Fault", "slip rate", "creep meter", fault, Parkfield

Our transcription: To derive the same kinds of information as provided by a creep meter but over a wider area, geophysicists use what's known as an alignment array.
This involves setting up markers, then conducting surveys across the San Andreas Fault to determine the local slip rate, the width of the slip zones, and patterns of deformation near the fault trace.
The alignment array surveys are also useful in helping scientists determine the best places to install creep meters.
The alignment array is similar to the creep meter in that it's measuring fault slip right at the surface trace.
However, the creep meter is a continuous monitoring device for the center of that slip area; whereas, the alignment array goes much farther away from the fault to be sure that we're not missing some important slip on auxiliary fractures out to the side.
In the alignment array, of course, we only get data when we make surveys; whereas, the creep meter can be run continuously, and we can look at that every day to see how much the center of this zone has actually moved.

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 USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/moviepage/08.01.22.html
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:26:06 PDT 2013  (chd)