Scientific Theme: Advanced Modeling and Observing Systems

Complementary Research: Faculty Fellows Research
Rio Grande Rift GPS Tectonics Project Underway
Anne Sheehan
Funding: NSF (project initiated with 2001 CIRES IRP seed grant)
Twenty-two high precision GPS monuments, with two more in progress, have been installed
and instrumented throughout Colorado and New Mexico as part of an NSF-funded project to
measure the crustal deformation of the Rio Grande Rift.
Accomplishments
The purpose of this NSF-sponsored study is to precisely measure the ground movement and
earthquake potential of the Rio Grande Rift in Colorado and New Mexico. Using state-of-the-art Global Positioning
System instruments at 24 sites in Colorado and New Mexico, we will track the rift‘s movement in millimeters during
most of the next five years. This study will provide modern satellite geodetic estimates of the active tectonics of
Colorado and New Mexico. The Rio Grande Rift formed between 35 and 29 million years ago when the crust began
to spread apart, triggering volcanism in the region. The Rio Grande Rift extends hundreds of miles from Colorado‘s
central Rocky Mountains to Mexico, and geologists have estimated it spreads apart up to five millimeters each year.
However, the margin of error in these estimates can be nearly as much as the estimates themselves. A better
understanding of the variable character of the rift could help us understand how and why tectonic plates undergo
stretching, as well as the earthquake and volcanic hazards within rift zones. The project is part of NSF‘s EarthScope
initiative, a NSF MRE project. Earthscope is funded by NSF and conducted in partnership with the U.S. Geological
Survey and NASA to study North American geologic evolution, earthquakes and volcanic activity.
Education and Outreach
Anne Sheehan teamed with the CU Science Explorers program to develop a hazards curriculum. This curriculum
was taught to nearly 1800 middle school aged children at 17 different locations throughout the state of Colorado.
Over 350 Colorado middle school teachers were trained on the hazards curriculum, and they were given materials to
take back to their classrooms to reach even more students.
Mark McCaffrey from the CIRES‘ Education and Outreach program developed a one-page FAQ handout on the Rio
Grande Rift experiment. This FAQ was adopted by the Earthscope national office and is being widely distributed
throughout the country. This FAQ has also been distributed at all of the CU Science Explorers workshops, to large
geology classes at the University of Colorado, and to the public.
CU graduate student Monica Guerra at Putney GPS station near
Silverton, Colorado, May 2007. Putney station is run with
assistance from the Center for Snow and Avalanche Studies.
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