ESRL Global Systems Division

NOAA GPS Met Network Contributes to U.S.G.S. Crustal Motion Study

Earth scientists at the US Geological Survey in Menlo Park, California, have analyzed GPS data observed between 1996 and 2000 for 62 CORS (Continuously Operating Reference Stations) distributed throughout the central and eastern United States. According to Richard Snay, CORS Program Manager at NOAA's National Geodetic Survey, "their results suggest that no significant horizontal crustal motion occurs in this part of the country, except possibly in the region encompassing that part of the Mississippi River located south of Illinois." In this region, roughly collocated with the New Madrid Fault Zone in Missouri, stations appear to be moving southward relative to the rest of the continent at an average rate of 1.7 mm/yr, with a standard error of 0.9 mm/yr. Snay says that "while this rate is not statistically significant, the fact that the motion occurs near New Madrid, MO--where earthquake risk is thought to be high--argues that the motion may be real."

Nine of the sites used in this study were established by the Forecast Systems Laboratory at NOAA Profiler Network Sites near Granada CO, Hillsboro KS, Haskell OK, Haviland KS, Lamont OK, Neodesha KS, Platteville CO, Purcell OK, and Vici OK.

Twenty-one additional sites used in the study were established buy the U.S. Coast Guard and/or U.S. Army Corps of Engineers. FSL has incorporated these sites into the NOAA GPS Water Vapor Demonstration Network by installing a GPS Surface Observing System (GSOS) meteorological package at each location. GSOS was developed for the GPS-Met project by the NWS National Data Buoy Center at Stennis Space Center, MS.

Further information on FSL's GPS work is available.

Contact information
Name: Seth I Gutman
Tel: 303-497-7031
gutman@fsl.noaa.gov