Subpixel offsets of Copernicus Sentinel 2 data, related to the displacement field of the Sulawesi Earthquake (2018, Mw 7.5)

Sulawesi lies within a complex fault system located between the Australian, Pacific, Philippine and Sunda Plates. The main active structure onshore at the western part of Central Sulawesi is the left-lateral NNW-SSE trending Palu-Koro strike-slip fault that forms the boundary between the North Sula and Makassar blocks. On 28 September 2018, a large tsunamigenic earthquake (Mw 7.5) struck the Minahasa Peninsula, Indonesia. The earthquake caused massive damages near Palu city, including onshore gravitational instabilities and a tsunami.

These data are the result of subpixel image correlation on Copernicus Sentinel-2 data (17 September 2018 and 2 October 2018) to derive the two-dimensional (East-West and North-South) horizontal co-seismic displacement field. In these data, the displacement field is expressed in meters. These results show a dominant senextral strike-slip motion on the onshore part of the Palu-Koro fault. Maximum displacement at the surface reached more than 8 meters at the location of Palu city. Processing is performed with COSI-CORR (Leprince et al., 2007). Data value higher than | 10 | meters should be considered as noise and disregarded. I used a correlation window size of 32 pixels with a sampling step of 16 pixels. A ramp has been removed from (separately) the North-South offsets and from the East-West offsets. The files are rasters of floating point values, served with a header file readable by ENVI software.

Sign conventions:

-North-South offsets: positive values to the North.

- East-West offsets:  positive values to the West.

http://www.esa.int/spaceinimages/Images/2018/10/Indonesia_earthquake_displacement_data

Copyright: Contains modified Copernicus Sentinel data (2018), processed at the French Geological Survey (BRGM)