May 20, 1990 Earthquake: Nakura, Juba, Maya, Uganda, South Sudan

May 20, 1990, Sudan. Some buildings damaged in the Juba area. Also damage in the Moyo area, Uganda. Felt in the Nakura area, Kenya and in Uganda. (reference #1053)

May 19, 1990 [probably describing May 20, 1990 event], Sudan. 31 killed. (reference #1250)

Several large earthquakes occurred in the south of the Sudan (now South Sudan) in May and July 1990. On 20 May 1990, a large earthquake of magnitude M7.2, shook the region located about 1120 km south of Khartoum and 100 km northeast of Juba, in the Mongola area. It was reported that 31 people lost their lives during this earthquake (http://earthquakes.findthedata.org/l/4608/Sudan- Juba-Maya-Uganda-Nakura). On 24 May 1990 another earthquake of magnitude M7.1 occurred in the same region, about 25 km south of the first one. This earthquake caused more substantial damage to private housing and government institutions than the first one but no loss of life was reported. Minor cracking in walls of some older buildings was observed in Juba. Most of the impact of the event fell on uninhabited areas. The focal mechanism of the main shock (20 May 1990) shows left-lateral strike-slip faulting (Gaulon et al., 1992, Girdler and McConnell, 1994). One of the nodal planes is parallel to the Aswa fault zone, a major Proterozoic tectonic feature. A line connecting the epicentres of the main events of May and July also strikes in the same direction. The rupture occurred in at least three steps, affecting a zone roughly 50 km long. However, the focal mechanism of the 20 May 1990 event was found to be different from the aftershocks, which all occurred on normal faults indicating a complicated tectonic regime in the epicentral area (Foster and Jackson, 1998). (reference #13028)