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Virginia Extensometer Network

Detailed Description

This static map shows the locations of the three existing extensometers (red) in the USGS' Virginia Extensometer Network with the location of a fourth future extensometer (green). The basemap is of the Virginia Coastal Plain and shows the severity of groundwater depletion, with darker blue indicating greater groundwater depletion. 

Franklin extensometer

  • Period of record: 1979-1995; 2016-present
  • Depth: 866 ft. below land surface (bls)
  • Location significance: proximal to pumping center

Suffolk extensometer

  • Period of record: 1982-1995; 2016-present
  • Depth: 1,599 ft. bls.

Nansemond extensometer

  • Period of record: 2018-present
  • Depth: 1,959 ft. bls.
  • Location significance: proximity to SWIFT facility


Public Domain.

Adapted from Fig. 9 in Eggleston, Jack, and Pope, Jason, 2013, Land subsidence and relative sea-level rise in the southern Chesapeake Bay region: U.S. Geological Survey Circular 1392, 30 p.,