Mapping of Surface Deformation and Displacement Associated with the 6.5 Magnitude Botswana Earthquake of 3 April 2017 Using DInSAR Analysis

• Autorzy: Abraham Thomas
• Języki publikacji: EN

Abstrakty

EN

The DInSAR analysis was performed for mapping surface deformation and displacement associated with the 6.5 magnitude Botswana earthquake of 3 April 2017 using Sentinel-1 data and SNAP. The analyses involved: coregistration of SAR images, interferogram formation, debursting, merging of sub-swaths, topographic phase removal, phase filtering, phase unwrapping, orthorectification and calculation of vertical displacement for two situations (unmasked and masked with a layer of coherence >0.6). The vertical displacement for the unmasked situation ranged from -122 mm to +136 mm whereas in the masked layer it ranged from -84 mm to +122 mm. Negative surface deformation (subsidence) is seen in the epicentre region and eastern, north-eastern, northern areas of the image whereas major positive surface deformations (uplift) are seen in the south-western, western and north-western corner part. Comparison of displacements with geology revealed that major deformation occurred in the Karoo basalts and lesser surface deformation has occurred in the Lebung Group rocks of the northern, NE and SW region. The elongated shape of deformation near the epicentre and positive vertical displacement seen towards the SW of the epicentre and negative vertical displacement seen towards NE of the epicentre reveals that the region has undergone uplifting and subsidence on either side of the area close to the epicentre (similar to faulting in a NW or SE direction). The boundaries of the uplift and subsidence regions inferred as long lineaments were digitised as faults. Comparison of the deformation with existing seismotectonic map revealed the existence of some north-westerly faults seen in the region.(original abstract)

Słowa kluczowe

EN

Disaster; Geography; Geology

PL

Katastrofa; Geografia; Geologia

• Czasopismo: Geomatics and Environmental Engineering
• Rocznik: 2020
• Numer: nr 14/4
• Strony: 81--100

Twórcy

autor

Abraham Thomas

• The Council for Geoscience, Pretoria, South Africa,

Bibliografia

• USGS: M 6.5 - 132 km WSW of Moijabana, Botswana. USGS, 2017. https:// earthquake.usgs.gov/earthquakes/eventpage/us10008e3k

Identyfikatory

DOI

10.7494/geom.2020.14.4.81