EarthScope is funded by the
National Science Foundation.

The long-base laser strainmeter (LSM) is an example of an extensometer, which measures the change in length along a line. Borehole strainmeters measure strain change by very accurately sensing change in the shape of an instrument cemented into rock. Because the dimensions of the instrument are only a few inches, very precise measurements are required. A typical signal is 10 nanostrain = 0.000 000 001mm across the instrument.

Focused dense clusters of 103 Borehole Strainmeters along fault zones and magmatic centers in western North America and Alaska.