In response to the disaster in Haiti on Jan. 12, NASA has added a series of science overflights of earthquake faults in Haiti and the Dominican Republic on the island of Hispaniola to a previously scheduled three-week airborne radar campaign to Central America.
NASA’s Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, left NASA’s Dryden Flight Research Center in Edwards, Calif., on Jan. 25 aboard a modified NASA Gulfstream III aircraft.
During its trek to Central America, which will run through mid-February, the repeat-pass L-band wavelength radar, developed by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., will study the structure of tropical forests; monitor volcanic deformation and volcano processes; and examine Mayan archeology sites.
After the Haitian earthquake, NASA managers added additional science objectives that will allow UAVSAR’s unique observational capabilities to study geologic processes in Hispaniola following the earthquake.
UAVSAR’s ability to provide rapid access to regions of interest, short repeat flight intervals, high resolution and its variable viewing geometry make it a powerful tool for studying ongoing Earth processes.
Lundgren says these upcoming flights, and others NASA will conduct in the coming weeks, months and years, will help scientists better assess the geophysical processes associated with earthquakes along large faults and better understand the risks.
UAVSAR uses a technique called interferometric synthetic aperture radar, or InSAR, that sends pulses of microwave energy from the aircraft to the ground to detect and measure very subtle deformations in Earth’s surface, such as those caused by earthquakes, volcanoes, landslides and glacier movements. Flying at a nominal altitude of 12,500 meters, the radar, located in a pod under the aircraft’s belly, collects data over a selected region.
It then flies over the same region again, minutes to months later, using the aircraft’s advanced navigation system to precisely fly over the same path to an accuracy of within 5 meters. By comparing these camera-like images, interferograms are formed that have encoded the surface deformation, from which scientists can measure the slow surface deformations involved with the buildup and release of strain along earthquake faults.
Since November of 2009, JPL scientists have collected data gathered on a number of Gulfstream III flights over California’s San Andreas fault and other major California earthquake faults, a process that will be repeated about every six months for the next several years. From such data, scientists will create 3-D maps for regions of interest.
Flight plans call for multiple observations of the Hispaniola faults this week and in early to mid-February. Subsequent flights may be added based on events in Haiti and aircraft availability.
