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by T T Molea and L Akromah (Council for Geoscience: Seismology Unit) . Recent Seismicity in the Mozambique Region. Seisan workshop October 2008 Norway. OUTLINE. The East African Rift System as a source of tectonics Seismicity of southern Africa 1620 - 2007
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byT T Molea and L Akromah (Council for Geoscience: Seismology Unit) Recent Seismicity in the Mozambique Region Seisan workshop October 2008 Norway
OUTLINE • The East African Rift System as a source of tectonics • Seismicity of southern Africa 1620 - 2007 • Mozambique earthquake of 22/02/2006 • Conclusion
USGS : 7.4 CTBTO : 6.4 CGS : 7.2. Epicentre : Machaze, in the ( Manica Province of Mozambique) Recording Time 22:19:05.8. This is believed to be the largest instrumentally recorded earthquake in Mozambique. Location & Magnitude
Damage & Intensity • Maximum vertical displacement; ± 2m. • Maximum horizontal displacement; ± 60km. • Shaking was strong enough to kill 4 people and injured at least 29 more. • Felt by people throughout Mozambique as well as in parts of the neighbouring countries of South Africa,Swaziland, Zambia, Zimbabwe.
Seismological Action Taken • Location by: USGS, CTBTO & CGS. • Moment Tensor by Harvard University • Source of earthquake mechanism investigated by Fenton & Bommer of Imperial College London. • Field survey by the DNG ( geological survey) of Mozambique.
Conclusion • This was the largest instrumentally recorded seismic event in Mozambique. • The event was felt over a wide area, thus leading to the suspicion that the attenuation in southern Africa is lower than previously thought. • The earthquake occurred on a previously unknown lineament which begs the question whether other capable geologic features may be present in the area.
IASPEI 2009 General Assembly • The Council for Geoscience invites you to attend the first IASPEI General assembly in Cape Town from 10-16 January 2009. • Summer-school 19-24 January 2009 • Registration 31 October 2009 • www.IASPEI2009sa.com • email: iaspei2009@geoscience.org.za • Hope to meet you all in Cape Town!!!
Seismic pattern of Southern Africa • Tectonics movement of fault plates in the East Africa Rift Valley. • Rift consist of 2 main lines : E & W branch. • W.branch starts in Lake Albert - DRC through Lake Malawi & terminate in S. Mozambique. • E. branch extends from triple junction between, Arabian,Nubian & Somalian plates in the North to Southern Tanzania. • A third south-eastern branch continue through the Mozambique channel.