Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 1 April 1994:
Vol. 264. no. 5155, pp. 67 - 70
DOI: 10.1126/science.264.5155.67
Prev | Table of Contents | Next

Articles

The 1990 to 1991 Sudan Earthquake Sequence and the Extent of the East African Rift System

R. W. Girdler 1 and D. A. McConnell 1

1 Department of Physics, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, United Kingdom

One of the largest earthquakes ever recorded in Africa (surface wave magnitude Ms = 7.2) occurred about 50 kilometers east of the Upper River Nile on 20 May 1990. Four days later, two more large earthquakes (Ms = 6.4 and 7.0) occurred about 50 kilometers to the northwest in the Nile Valley. In the following months, a further 60 events were recorded by seismic stations worldwide. The earthquakes are associated with two fault systems: one east of the Nile with azimuth southeast and one along the Nile Valley with azimuth north-northeast. The activity alternated between the two fault systems and indicates that the northern extremity of the western branch of the East African Rift System extends at least 350 kilometers north of Lake Albert.

Submitted on September 28, 1993
Accepted on January 24, 1994


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Recurrence of Large Earthquakes in Magmatic Continental Rifts: Insights from a Paleoseismic Study along the Laikipia-Marmanet Fault, Subukia Valley, Kenya Rift.
O. Zielke and M. R. Strecker (2009)
Bulletin of the Seismological Society of America 99, 61-70
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)