Remote sensing and the search for surface rupture, Haiti 2010

Abstract

Minutes after the January 12, 2010 Haiti earthquake, most geologists and seismologists assumed that from its shallow teleseismic location and its largely strike-slip mechanism that a significant rupture must have occurred on the transform plate boundary south and west of Port au Prince. Within hours, plans were being made by geologists to map the anticipated rupture and, if possible, to trench it to obtain a record of paleoseismic slip. However, remote sensing images available a few days after the earthquake revealed raised corals and no significant plate boundary slip, and we now know that shallow slip was transpressive and that no surface rupture occurred. A week after the earthquake, it was clear that scientific visits to the region would be much delayed by the continuing needs of emergency response teams and military support who had commandeered access to the airport at Port au Prince. Serendipitously on 20 January, one of the authors accompanied a film crew on a chartered flight from nearby Santo Domingo with the quest to record the tectonic reasons for the disaster and to document the details of structural damage. At the time, there was still no clear idea of whether the transform boundary had a surface rupture, but there was abundant evidence for surface deformation from Google Earth images showing raised corals and collapsed coastlines along the Lêogáne coast. This article briefly describes communications between remote geologists and the ground-based crew who were guided to critical areas in the search for surface deformation using remote sensing data.