Seismic Instruments

A transportable array of 400 portable, unmanned three-component broadband seismometers deployed on a uniform grid that is systematically covering the US. Each USArray station includes the instrumentation necessary to continuously sense, record, and transmit ground motions from a wide range of seismic sources, including local and distant earthquakes, volcanic eruptions, and other natural and human-induced activities.

Global Positioning Instruments

A backbone network of 116 new and 20 existing GPS receivers provide a long-wavelength, long-period synoptic view of the entire plate boundary zone including the eastern US. Additionally, a focused dense clusters of 775 permanent GPS receivers are dedicated for observation along fault zones and magmatic centers in western North America and Alaska.

Strainmeter Instruments

Focused dense clusters of 175 strainmeters along fault zones and magmatic centers in western North America and Alaska are designed to enhance our understanding of plate boundary processes and volcanic events. 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.

Campaign/Flexible Instruments

Campaign/Flexible instruments allow for focused observation and study of key geophysical locals and are available to the scientific community through proposals approved by the NSF. These instruments can be used to augment the permanent instruments, extend investigations into Canada and Mexico, and respond to volcanic and/or tectonic crises.