A team of researchers from the University of Colorado at Boulder and the University of New Mexico have been awarded a $600,000 grant from the National Science Foundation’s EarthScope program to precisely measure the ground movement in the Rio Grande Rift in Colorado and New Mexico. The project is part of the NSF’s EarthScope initiative, a partnership with the U.S. Geological Survey and NASA to study the structure of North America, its geologic evolution, earthquakes and volcanic activity.
The primary goal of the project is to understand what the stretching rates are in the rift and what the rates measured at the surface imply about the stretching of the North American plate at deeper levels. Using state-of-the-art global positioning system (GPS) instruments at 24 sites from Colorado through southern New Mexico, the research team will track the rift’s movement with millimeter-accuracy over the course of the next five years. The study will provide unprecedented data about the volcanically active and earthquake-prone region of the Rio Grande Rift.
“Our goal is to try and understand the rates of motion today,” said UNM Assistant Professor Mousumi Roy, of the Earth and Planetary Sciences Department. “The information we gather will tell us about how the North American plate is breaking apart at the Rio Grande Rift and about the earthquake hazards posed by the rift.”
The Rio Grande rift is the easternmost deforming province within the tectonically active western margin of North America. The rift is undergoing stretching and extension manifested by higher probabilities of earthquake occurrence than in surrounding regions.
The UNM effort is being led by Roy and the CU-Boulder team which includes: Professor Anne Sheehan (affiliated with CU-Boulder’s Cooperative Institute for Research in Environmental Sciences); Associate Professor Steve Nerem, Aerospace Engineering; and Research Associate Tony Lowry of Physics.
Emily Jones, a part-time research assistant from UNM, also worked with Roy on the project this past summer. Additionally, the team is actively recruiting graduate and undergraduate students at CU-Boulder and the UNM to be trained in GPS measurement and analysis as part of the project.
“The Rio Grande rift extends hundreds of miles from Colorado’s central Rocky Mountains to Mexico, and geologists have estimated it spreads apart at rates up to 1-2 millimeters each year,” said Sheehan.
The team will install 11 GPS sites in central and southern Colorado.
In New Mexico, 13 sites will be setup in three different areas throughout the state. Five sites will be setup near the latitude of Taos, four in central New Mexico near Albuquerque and four in southern New Mexico near Las Cruces. The teams will compare their measured rates of motion with all other available datasets, including seismic velocities in the crust and mantle, gravity, surface heat flow and geologic data. The data will be combined to build computer models of the processes that control how tectonic plates undergo rifting.
“We will combine what we learn from the GPS measurements with other geophysical and geologic data to try and understand the forces that are pulling the North American plate apart and creating the Rio Grande Rift,” said Roy. “What’s intriguing to me is to learn about why north of Socorro the Rio Grande Rift is a narrow feature, with narrow fault-bounded basins, whereas to the south we get a broader region of extension comparable to the famous Basin and Range province of Utah and Nevada.”
Community outreach is also an important part of the project. A workshop for in-service teachers in New Mexico is planned as part of the NSF-funded Rio Grande GPS study (jointly by Roy and Dr. Matthew Nyman of the Dept. of Earth and Planetary Sciences at UNM).
The outreach workshop will focus on the basics of earthquakes, earthquake activity in New Mexico and the Rio Grande GPS study. Part of the workshop will be used to recruit teachers to actively participate in the GPS study as well as investigate avenues to become involved in future EarthScope science activities.
The Science Education Institute of the Southwest (SEIS) sponsors the teacher workshop. SEIS is a collaborative between the University of New Mexico, Sandia National Laboratories and the Albuquerque Public School district with a focus on improving science education at all levels.
For more information on the Rio Grande rift project, visit: http://epswww.unm.edu/facstaff/mroy/rgr_nm, or http://cires.colorado.edu/science/groups/sheehan/projects/riogrande/.
Contact: Steve Carr, (505) 277-1821
Posted by scarr at September 20, 2005 05:15 PM