Pipe Borehole Dual-Stage Extensometer

A green and yellow USGS extensometer installed in a shed

Detailed Description

Extensometers are used in land subsidence studies to measure the compaction and expansion of the aquifer system to some depth. This pipe borehole dual-stage extensometer was built in 2008 in San Lorenzo, CA and measures compaction from 10 to about 300 meters. The illustration highlights the features that can be seen in the photograph.


Image Dimensions: 1317 x 993

Date Taken:

Location Taken: San Lorenzo, CA, US