loading page

The Malawi Active Fault Database: an onshore-offshore database for regional assessment of seismic hazard and tectonic evolution
  • +10
  • Jack Nicholas Williams,
  • Luke N J Wedmore,
  • Christopher A. Scholz,
  • Folarin Kolawole,
  • Lachlan J.M. Wright,
  • Shillington Donna,
  • Ake Fagereng,
  • Juliet Biggs,
  • Hassan Mdala,
  • Zuze Dulanya,
  • Felix Mphepo,
  • Patrick Rafiki N Chindandali,
  • Maximilian J. Werner
Jack Nicholas Williams
Cardiff University

Corresponding Author:[email protected]

Author Profile
Luke N J Wedmore
University of Bristol
Author Profile
Christopher A. Scholz
Syracuse University
Author Profile
Folarin Kolawole
BP America
Author Profile
Lachlan J.M. Wright
Syracuse University
Author Profile
Shillington Donna
University of Northern Arizona
Author Profile
Ake Fagereng
Cardiff University
Author Profile
Juliet Biggs
University of Bristol, UK
Author Profile
Hassan Mdala
Geological Survey of Malawi
Author Profile
Zuze Dulanya
Chancellor College
Author Profile
Felix Mphepo
Geological Survey of Malawi
Author Profile
Patrick Rafiki N Chindandali
Geological Survey Department of Malawi
Author Profile
Maximilian J. Werner
University of Bristol
Author Profile

Abstract

We present the Malawi Active Fault Database (MAFD), a geospatial database of 114 active fault traces in Malawi, and in neighboring Tanzania and Mozambique. The MAFD has been developed from a multidisciplinary dataset: high resolution digital elevation models, field observations, aeromagnetic and gravity data, and seismic reflection surveys from offshore Lake Malawi. Active faults longer than 50 km are found throughout Malawi, where seismic risk is increasing due to its rapidly growing population and its seismically vulnerable building stock. The MAFD also provides an opportunity to investigate the population of normal faults in an incipient continental rift. We find that the null hypothesis that the distribution of fault lengths in the MAFD is described by a power law cannot be rejected. Furthermore, a power-law distribution of faults in Malawi is consistent with its thick seismogenic crust (~35 km), and low (<8%) regional extensional strain that is predominantly (50-75%) accommodated across relatively long hard-linked border faults. Cumulatively, the data and inferences drawn from the MAFD highlight the importance of integrating onshore and offshore geological and geophysical data to develop active fault databases along the East African Rift and similar continental settings, both to understand the regional seismic hazard and tectonic evolution.
May 2022Published in Geochemistry, Geophysics, Geosystems volume 23 issue 5. 10.1029/2022GC010425