Community Announcement: CMG-3T Sensors Available

Dear Community Members,

At the close of the EarthScope Transportable Array project, IRIS announces the availability of surplus Guralp CMG-3T seismometers.  

Many former Transportable Array (TA) seismometers have already been reallocated for use by other NSF-supported NSF SAGE programs like the GSN and PASSCAL. The Guralp CMG-3T sensors currently available were deployed by the TA during the Lower-48 rollout (2005-2015) and are no longer needed to support ongoing NSF SAGE programs.

There are approximately 30 CMG-3T seismometers, plus ancillary equipment (cables and, if requested, breakout boxes) available for interested domestic network operators. All equipment was either tested and deemed to be in good working condition, or was last reported in good working condition when removed from active deployment. However, the current working status is not guaranteed.

As approved by the IRIS Board of Directors and NSF, IRIS is now accepting requests from educational institutions or government agencies operating domestic networks who are interested in acquiring these surplus sensors. To submit a request, please visit this link:

The seismometers and ancillary equipment are being offered as-is, with no ongoing technical support being provided by IRIS. We are prioritizing requests from domestic network operators who currently own CMG-3Ts and have a working knowledge of their operational characteristics, troubleshooting, data handling, etc. Requests will also be considered from interested parties who may not currently own CMG-3Ts, and who stipulate that they understand and can utilize this equipment without further assistance.

Requests must be submitted by Friday, September 10, 2021 and will be reviewed by facility staff with the final decision approved by the IRIS Board of Directors. Selected applicants will be notified by September 30, and equipment must be accepted and received no later than October 31, 2021.

Shipping cases are not being provided with these sensors; however, they will be shipped to the selected applicants within facility shipping cases, which must then be sent back to IRIS. All shipping costs (both for the sensors/equipment and return of empty shipping cases) will be the responsibility of the selected applicants.

We hope that these sensors, which have already provided a wealth of data for the community, will continue to support seismologic research and monitoring for years to come.

Questions may be directed to Robert Busby, TA Manager,