NASA Airborne Radar To Study Quake Faults in Haiti

NASA Airborne Radar To Study Quake Faults in Haiti

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.

Tectonic Plate Line runs through Haiti

The sharp diagonal line exactly at the image center is the Enriquillo fault. Port-au-Prince is immediately to the left (north) at the mountain front and shoreline.

A magnitude 7.0 earthquake occurred on January 12, 2010, at Port-au-Prince, Haiti, with major impact to the region and its citizens.

This perspective view of the pre-quake topography of the area clearly shows the fault that is apparently responsible for the earthquake as a prominent linear landform immediately adjacent to the city.

Elevation is color coded from dark green at low elevations to white at high elevations, and the topography is shaded with illumination from the left. The topography in this image is exaggerated by a factor of two.

The sharp diagonal line exactly at the image center is the Enriquillo fault. Port-au-Prince is immediately to the left (north) at the mountain front and shoreline.

The Enriquillo fault generally moves left-laterally (horizontally, with features across the fault shifting to the left when the fault breaks in an earthquake), but vertical movements occur along the fault where irregularities in the fault line cause local compression or extension of the earth.

Meanwhile, movements of the topography at the Earth's surface can falsely appear to be vertical where mountain slopes are cut and misaligned by horizontal shifts of the fault.

Additionally, differing erosion rates on the two sides of the fault, due to the juxtapositioning of differing rock types by the fault, can give the appearance of vertical offsets of the current topographic surface.

All of these real and apparent horizontal and vertical offsets of the topographic surface may (and likely do) occur here, making the fault easily observed in the topographic data.

The elevation data used in this image were produced by the Shuttle Radar Topography Mission (SRTM), flown aboard Space Shuttle Endeavour in February 2000. SRTM acquired elevation measurements for nearly all of Earth's landmass between 60 degrees North and 56 degrees South latitudes.

For many areas of the world, SRTM data provide the first detailed three dimensional observation of landforms at regional scales.

ESA ENVISAT: Haiti Damaga Evaluation Pictures

Damage evaluation map based on satellite data over the Port-au-Prince area of Haiti, following a 7.0 magnitude earthquake and several aftershocks that hit the Caribbean nation on 12 January.

Map based on data from CNES's SPOT-5, JAXA's ALOS and the U.S.-based GeoEye-1 satellites; processed by SERTIT.

Credits: CNES, JAXA, GeoEye, SERTIT

HAITI Earthquake was predicted, expected and overdue

A magnitude-7.0 earthquake struck Haiti yesterday afternoon local time, about 16 kilometres south-west of the country's capital, Port-au-Prince, and at a depth of 10 kilometres. Powerful aftershocks - 32 at the latest count - continue to affect the region.

A major earthquake in the region of Haiti was long overdue, CNN reports. In fact, a group of scientists from the US and Jamaica warned in 2008 that a fault zone on the south side of the island - the Enriquillo-Plaintain Garden fault zone - presented a danger.

They predicted that a magnitude-7.2 earthquake would result if all of the strain along the fault "is released in a single event today", according to the abstract the team presented at the 18th Caribbean Geological Conference.

The earthquake is the worst that has affected the Haiti region in two centuries and around 3 million people are likely to have been "severely shaken" by the earthquake, the BBC reports. A United States Geological Survey "shakemap" pictured above shows the intensity and strength of ground shaking.

"Many buildings, including a hospital and the presidential palace in the capital Port-au-Prince, have collapsed, burying residents under the rubble," according to the British Geological Survey's website.

The United Nations has issued a statement to say that its local headquarters in Haiti have "sustained serious damage along with other UN installations" and "a large number" of employees are unaccounted for, adds the BBC.

According to Paul Mann, who was one of the scientists who gave the warning, Haiti is particularly vulnerable to earthquake damage because many people live in poorly constructed housing on steep slopes.

The largest earthquakes Haiti has experienced hit in 1751, 1770, 1842, 1860 and 1887, according to Mann's 2005 book, Active Tectonics and Seismic Hazards of Puerto Rico, the Virgin Islands, and Offshore Areas.

The region has had its fair share of natural disasters: many are still homeless following the spate of hurricanes and storms that ravaged Haiti in 2008, killing 900, according to British newspaper The Times.