This satellite image shows the area around Caracas, Venezuela, which was hit by a double earthquake on Wednesday, 24 June, at about 18:00 local time (about midnight central European time).
The ground deformation captured in this image is based on data from the Copernicus Sentinel-1 satellites, which carry powerful remote-sensing instruments that can detect differences in ground level with millimetre precision.
The map is an interferogram derived from the comparison of Sentinel-1 data on two dates: on the 18 June before the earthquakes and on 25 June a day after. The fringed pattern on the north of the image shows the extent of the region where ground deformation occurred. The preliminary data indicate ground displacement of the order of 30 cm in the line of sight.
The quakes of 7.2 and 7.5-magnitude came less than a minute apart and were detected by the US Geological Survey (USGS). According to the USGS, the 7.2-magnitude tremor occurred first and was followed, just 39 seconds later, by the mainshock tremor of 7.5-magnitude. Both the tremors were caused by seismic events at a relatively shallow depth, causing strong shaking of buildings and extensive damage and fatalities.
The northern coast of Venezuela lies on the San Sebastian fault system, a major geological fault that extends for about 500 km along the Venezuelan coast and the Caribbean sea. The 7.5-magnitude quake is the strongest earthquake to hit Venezuela since 1900.
This image shows the affected area, which extends from Caracas, in northern Venezuela, towards the city of Puerto Cabello, about 210 km west of the capital. The city of La Guaira, some 20 km north of Caracas, is one of the worst-hit areas.
The Copernicus Sentinel-1 mission is equipped with a C-band Synthetic Aperture Radar (SAR) instrument. It monitors the changing shape of Earth’s land surfaces with very precise measurements that are based on a complex data processing method called SAR interferometry (InSAR). The images produced, known as interferograms, are created by the satellite emitting a radar signal, and then recording data when the signal bounces back off Earth’s surfaces. Two or more readings over the same location, taken at different times, are used to calculate surface displacement.