These pages contain preliminary results from GPS
measurements of the deformation caused by the earthquake process. Here you can
also find a results from the Geodolite trilateration measurement program.
Automatic Processing
USGS GPS data are automatically processed
to produce maps of velocity and time series of position for
the sites. During the automatic processing, individual stations
are treated independently. Results from this automatic processing
can be accessed through any of the following three pages:
North
America Map
Clickable map of North America with links to velocities and time series.
California-Nevada
Map
Clickable map of California-Nevada with links to velocities and time series.
Campaign
List
List of Campaigns with links to velocities and time series.
(Most useful if you know the campaign name of interest.
If not, see maps above.)
Google Earth files
Display USGS campaign mode GPS stations in Google Earth.
To display stations, download one of the KML files and open it in Google Earth.
For some of these sites, we also have velocities
obtained from a network adjustment:
QOCA
Processing
Links to campaigns that have been processed in a network
mode with the Quasi-Observational Combined Analysis (QOCA)
software (Estimating Regional Deformation from a Combination
of Space and Terrestrial Geodetic Data, D. Dong, T. A.
Herring, and R. W. King, Journal of Geodesy, 72, 200-214,
1998).
Information about GPS and GPS Processing
The following two links contain information
details about our processing system, and about how GPS works
and how it is used:
GPS
Processing Manual
A description of the GPS processing system used to produce
the results linked above.
About
GPS
A very brief introduction to GPS and how it is used in
earthquake research.
Geodolite Results and Ancillary Information
From 1970 to about 1990, we measured deformation using a Geodolite, an Electromagnetic
Distance Measuring instrument. Line lengths and positions for all of these measurements
are available:
Geodolite
Results
There are two files accessible: One contains approximate
positions for all the stations. The other contains the
observed line lengths
North
America Map
This map shows geodolite station locations across North America.
California-Nevada
Map
This map shows geodolite station locations across California and Nevada.
Campaign
List
List of geodolite networks with links to all line lengths measured in each net.
(Most useful if you know the campaign name of interest.
If not, see maps above.)
Euler Poles
A collection of published and unpublished Euler Poles for
various plates
U.S. Geological Survey, Earthquake Hazards Program
URL http://quake.wr.usgs.gov/research/deformation/gps/index.html
Contact:wprescott@usgs.gov
Last modification: April 13, 2001