Ken Hudnut of the U.S. Geological Survey discussed the use of LIDAR for both the Chilean and Haiti earthquakes at the ILMF event. Using the same scale, he showed the dramatic difference in size and shake pattern between these quakes. The Chilean fault size area was 60,000 sq km vs. 600 sq km in Haiti. He overlaid the PAGER product and combined with population centers, showing that the shaking patterns happened greatest in the densest areas in Haiti.
The Chilean earthquake was 500 times more energetic than in Haiti, although there were 300 times more deaths in Haiti, making it the sixth most lethal in recorded history. Given the level of deaths, the U.S. Geological Survey is studying Haiti in detail, with funding from USAID to understand what happened there, particularly since the global hazard map didn’t pinpoint the Haiti fault as a significant hazard area.
Construction, population density and strong shaking combined to make the Haiti quake the most fatal category 7 earthquake. The energy from the rupture of the Enriquillo fault largely went away from Port au Prince, making it less damaging than it could have been. The surface slip on the fault was mostly deep, without much surface faulting.
The National Geospatial Intelligence Agency has flow a system called ALIRT for LIDAR acquisition along the fault zone. The Rochester Institute of Technology/Kucera International flew a high-resolution collection project funded by the World Bank. LIDAR data has been shared via KMZ file through OpenTopography.org, and anyone can take a look.
The LIDAR and imagery combination provides a means to quantify land changes, and to assess in the field when different land changes occurred. Feature offsets give a sense of the slip rate along the fault over time. LIDAR is tremendously powerful for the assessment of offset features to understand where damage occurred in the past.
The USGS will be doing an overall hazard map of the area, and LIDAR has been very helpful to assess damage, understand coastal deformation issues, and has enabled the determination of the location of the fault in areas where it wouldn’t be detectable before.
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I agree totally to Ken, that Lidar could give a stong input to the post earthquake analysis. We do have a full Lidar coverage of in total 75.000 skm of the the affected area in Chile available. The data was collected within the last 3 years and we are presently recollecting several areas to compare pre- and post event data. (www.digimapas.cl)