Rapid Damage Mapping for the 2015 M7.8 Gorkha Earthquake using Synthetic Aperture Radar Data from COSMO-SkyMed and ALOS-2 Satellites

Friday, 18 December 2015: 17:00
309 (Moscone South)
Sang-Ho Yun1, Kenneth W Hudnut2, Susan E Owen3, Frank Webb4, Mark Simons5, Patrizia Sacco6, Eric Michael Gurrola3, Gerald Manipon1, Cunren Liang7, Eric Jameson Fielding7, Pietro Milillo5, Hook Hua3 and Alessandro Coletta6, (1)Jet Propulsion Laboratory, Pasadena, CA, United States, (2)USGS Pasadena Field Office, Pasadena, CA, United States, (3)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (4)JPL/NASA/Caltech, Pasadena, CA, United States, (5)California Institute of Technology, Pasadena, CA, United States, (6)Italian Space Agency, Rome, Italy, (7)Jet Propulsion Lab Caltech, Pasadena, CA, United States
The April 25, 2015 M7.8 Gorkha earthquake caused more than 8,000 fatalities and widespread building damage in central Nepal. Four days after the earthquake, the Italian Space Agency’s (ASI’s) COSMO-SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area. Nine days after the earthquake, the Japan Aerospace Exploration Agency’s (JAXA’s) ALOS-2 SAR satellite covered larger area. Using these radar observations, we rapidly produced damage proxy maps derived from temporal changes in Interferometric SAR (InSAR) coherence. These maps were qualitatively validated through comparison with independent damage analyses by National Geospatial-Intelligence Agency (NGA) and the UNITAR’s (United Nations Institute for Training and Research’s) Operational Satellite Applications Programme (UNOSAT), and based on our own visual inspection of DigitalGlobe’s WorldView optical pre- vs. post-event imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork.