Aeromagnetic, Gravity, and Differential Interferometric Synthetic Aperture Radar Analyses Reveal the Causative Fault of the 3 April 2017 M_w 6.5 Moiyabana, Botswana, Earthquake

Author

Folarin Kolawole
Estella A. Atekwana, Missouri University of Science and TechnologyFollow
S. Malloy
Dorothy Sarah Stamps
Raphael Grandin
Mohamed G. Abdel Salam, Missouri University of Science and TechnologyFollow
Khumo Leseane
Elisha M. Shemang

Abstract

On 3 April 2017, a M_w 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.

Recommended Citation

F. Kolawole et al., "Aeromagnetic, Gravity, and Differential Interferometric Synthetic Aperture Radar Analyses Reveal the Causative Fault of the 3 April 2017 M_w 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 https://doi.org/10.1002/2017GL074620

Department(s)

Geosciences and Geological and Petroleum Engineering

Sponsor(s)

National Science Foundation (U.S.)

Comments

Research partially supported by NSF: EAR10-09988

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

Geographic Coverage

Botswana

International Standard Serial Number (ISSN)

0094-8276

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2017 American Geophysical Union (AGU), All rights reserved.

Publication Date

09 Sep 2017