On 3 April 2017, a Mw 6.5 earthquake struck Moiyabana, Botswana, nucleating at >20 km focal depth within the Paleoproterozoic Limpopo-Shashe orogenic belt separating the Archean Zimbabwe and Kaapvaal Cratons. We investigate the lithospheric structures associated with this earthquake using high-resolution aeromagnetic and gravity data integrated with Differential Interferometric Synthetic Aperture Radar (DInSAR) analysis. Here we present the first results that provide insights into the tectonic framework of the earthquake. The ruptured fault trace delineated by DInSAR aligns with a distinct NW striking and NE dipping magnetic lineament within the Precambrian basement. The fault plane solution and numerical modeling indicate that the cause of the earthquake was 1.8 m displacement along a NW striking and NE dipping normal fault, rupturing at 21-24 km depth. We suggest that this seismic event was due to extensional reactivation of a crustal-scale Precambrian thrust splay within the Limpopo-Shashe orogenic belt.
F. Kolawole et al., "Aeromagnetic, Gravity, and Differential Interferometric Synthetic Aperture Radar Analyses Reveal the Causative Fault of the 3 April 2017 Mw 6.5 Moiyabana, Botswana, Earthquake," Geophysical Research Letters, vol. 44, no. 17, pp. 8837-8846, American Geophysical Union (AGU), Sep 2017.
The definitive version is available at http://dx.doi.org/10.1002/2017GL074620
Geosciences and Geological and Petroleum Engineering
National Science Foundation (U.S.)
Keywords and Phrases
Botnet; Earthquakes; Geophysics; Gravitation; Interferometry; Radar; Synthetic Aperture Radar; Aeromagnetics; D-inSAR; Differential Interferometric Synthetic Aperture Radars; Extensional Reactivation; Fault Plane Solutions; Intraplate Earthquakes; Lithospheric Structure; Precambrian Basement; Faulting; Aeromagnetic Survey; Craton; Displacement; Earthquake; Gravity; Intraplate Process; Lineament; Numerical Model; Orogenic Belt; Precambrian; Radar Interferometry; Seismic Data; Synthetic Aperture Radar; Botswana; Limpopo Belt; Zimbabwe; Aeromagnetics; DInSAR; Extensional Reactivation; Gravity
International Standard Serial Number (ISSN)
Article - Journal
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