Just two days after Haiti’s earthquake, Leonel Fernandez, the president of the neighboring Dominican Republic, ordered a helicopter to fly him over the border for an unannounced visit. He was worried about his Haitian counterpart and friend, Rene Preval, who was still incommunicado.

What made this neighborly gesture remarkable was that the two countries that share the island of Hispaniola have long been divided by mutual suspicion. During a previous term in the 1990s, Fernandez became the first Dominican president to visit Haiti in 60 years.

Fernandez says he found Preval alone in a small, dark back office at a police station near the airport. They talked about how the Dominican Republic could help. It has, a lot. Crews of Dominicans, including engineers, telecoms technicians and the Red Cross, were among the first to join the relief effort.

Fernandez dispatched 15 mobile kitchens to provide hot meals to survivors. He is now sending 100 old buses, refitted with desks and chairs, to serve as temporary classrooms. Dominican health teams are helping to treat earthquake survivors at a makeshift hospital in Jimani on the border. Victor Atallah, a Dominican cardiologist, is building a rehabilitation clinic in Jimani where he plans to fit amputees with prosthetic limbs.

In June, Fernandez will host a donor conference in Santo Domingo. There is understandable self-interest in his admirable solidarity.

NASA is sending a radar-equipped jet to Haiti to make 3-D maps of the deformation caused by the magnitude 7 earthquake on Jan. 21 and multiple aftershocks that continue to occur.

The Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, was already scheduled to head to South America aboard a modified Gulfstream III to study volcanoes, forests and Mayan ruins. NASA added the island of Hisapaniola to the itinerary to help study faults in both Haiti and the Dominican Republic.

“UAVSAR will allow us to image deformations of Earth’s surface and other changes associated with post-Haiti earthquake geologic processes, such as aftershocks, earthquakes that might be triggered by the main earthquake farther down the fault line, and the potential for landslides,” JPL’s Paul Lundgren, the principal investigator for the Hispaniola overflights, said in a press release Wednesday.

“Because of Hispaniola’s complex tectonic setting, there is an interest in determining if the earthquake in Haiti might trigger other earthquakes at some unknown point in the future,” Lundgren said, “either along adjacent sections of the Enriquillo-Plantain Garden fault that was responsible for the main earthquake, or on other faults in northern Hispaniola, such as the Septentrional fault.”

uavsarThe UAVSAR, which left NASA’s Dryden Flight Research Center in Edwards, Calif., on Jan. 25, will flyover Hispaniola multiple times this week and again in early February.

Since November 2009, the radar has been mapping the San Andreas and other major faults in California. The 3-D data will help scientists better understand the state’s seismic risk.

UAVSAR works by sending microwaves to the ground from a pod under the aircraft flying at about 41,000 feet and recording the return signal. The differences in the times it takes waves to return from points on the ground to the plane gives information about the topography. By hitting the same target from different angles as the plane flighs overhead, a 3-D image can be made. Very precise details about ground motion can be calculated by flying over the same area later, giving scientists information about strain buildup on a fault.

The Hispaniola data will be made public in a few weeks. The Dominican Republic flyovers could help scientists understand future earthquakes on the Septrional fault.