Seismicity and Seismotectonic Study of Juba and Mongala Area, South Sudan
[1]
Khalda Yassin Ibrahim, Department of Seismology, Remote Sensing and Seismology Authority, National Center for Research, Khartoum, Sudan.
[2]
Abd Alhafiz Gad El Mula, Department of Geology, Faculty of Science, Khartoum University, Khartoum, Sudan.
Juba and Mongala are one of the largest cities in the South Sudan. These areas and its surrounding were recognized as seismic areas which encourage various seismic and seismotectonic studies to be carried out. The big earthquakes that occurred in Juba area during nineties of this century are one of the largest earthquakes recorded in Africa. This study aims to throw the light on seismic activity and seismotectonic around Juba and Mongala area. Earthquake aerial distribution illustrated that earthquakes are of shallow type and the earthquakes of 1990 are the most recent example of this type of events. The depth distribution is between 0 and 47km and the magnitude is ranging between 3.9 and 7.1 mb. Rose diagram was created based on the lineaments from the geological map and digital elevation model which is revealed that most of the lineaments trend either in the northeast, northwest, north –south and east - west directions. The earthquake epicenters are found to be associated with the lineaments. A fault plane solution of 20, 24 May and 9 July 1990 indicate that the plane of the fault is directed northwest/ southeast and east/west. Finally, seismic zone map and seismotectonic map of the study area were constructed. This study is the first step towards performing a successful seismic hazard assessment and mitigation.
Seismic Activity, Digital Elevation Model, Rose Diagram, Lineaments, Fault Plane Solution, Seismotectonic Map
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