Open AccessSeismic hazard in central southern Africa
Author(s) -
Hlatywayo Dumisani John
Publication year - 1997
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.1997.tb01868.x
Subject(s) - seismology , geology , induced seismicity , seismic hazard , fault (geology) , magnitude (astronomy) , maximum magnitude , peak ground acceleration , rift , structural basin , hazard map , earthquake scenario , spectral acceleration , hazard analysis , tectonics , ground motion , geomorphology , landslide , physics , astronomy , aerospace engineering , engineering
SUMMARY Seismic hazard maps of central‐southern Africa where hazard has been expressed in terms of peak ground acceleration for an annual probability in excess of 10 ‐1 show relatively high values that distinguish the seismic hazard potential of the Deka fault zone, the mid‐Zambezi basin‐Luangwa rift and western central Mozambique. In areas such as central‐southern Africa where little is known about the geology of the region and the fault systems have not been fully mapped, seismic hazard potential may be estimated from seismicity and broad‐scale fault features. For this region, such potential is based on earthquake magnitude M s ≥ 6. Events of such magnitude have recently occurred in the mid‐Zambezi basin, southern Zimbabwe and western‐central Mozambique. This paper follows the conventional probabilistic hazard analysis procedure, defining seismic source zones from seismicity based on instrumental records from a cataloque that spans a period of 83 years. Geological and geomorphological features in the region are described on the mesoscale and are correlated with the seismicity as broad fault zones. The scarcity of strong‐motion accelerogram data necessitated the formulation of attenuation values based on random vibration theory (RVT).