T51G-3003
Crustal Structure in Northern Malawi and Southern Tanzania surrounding Lake Malawi and the Rungwe Volcanic Province

Friday, 18 December 2015
Poster Hall (Moscone South)
David Borrego1, Marsella Kachingwe2, Andy Nyblade1, Donna J Shillington3, James B Gaherty4, Cynthia J Ebinger5, Natalie J Accardo6, John Paul O'Donnell2, Gabriel John Mbogoni7, Gabriel Daudi Mulibo8, Patrick R.N. Chindandali9, Felix Mphepo9, Richard Ferdinand-Wambura8 and Gabrielle Tepp5, (1)Pennsylvania State University Main Campus, University Park, PA, United States, (2)Penn State University, Chicago, IL, United States, (3)Columbia University of New York, Palisades, NY, United States, (4)Organization Not Listed, Washington, DC, United States, (5)University of Rochester, Rochester, NY, United States, (6)Columbia University, New York, NY, United States, (7)Geological Survey of Tanzania, Dodoma, Tanzania, (8)University of Dar es Salaam, Dar es Salaam, Tanzania, (9)Geological Survey of Malawi, Zomba, Malawi
Abstract:
Crustal Structure in Northern Malawi and Southern Tanzania surrounding Lake Malawi and the Rungwe Volcanic Province

David Borrego, Marsella Kachingwe, Andrew Nyblade, Donna Shillington, James Gaherty, Cynthia Ebinger, Natalie Accardo, J.P. O’Donnell, Gabriel Mbogoni, Gabriel Mulibo, Richard Ferdinand, Patrick Chindandali, Felix Mphepo, Gabrielle Tepp, Godson Kamihanda

We investigate crustal structure around the northern end of Lake Malawi and in the Rungwe Volcanic Province using teleseismic receiver functions from the SEGMeNT broadband seismic network. The SEGMeNT network includes 55 broadband stations deployed in northern Malawi and southern Tanzania, with station spacing of 20-50 km. Fourteen stations were deployed in August 2013, and an additional of 41 stations were added to the study region beginning June/July 2014. Fifteen stations are located in Malawi and 40 stations in Tanzania. Data from teleseismic earthquakes with magnitude 5.5 or greater in the 30 to 90 degrees distance range have been used to calculate P-wave receiver functions. Estimates of Moho depth and Vp/Vs ratios have been obtained by using the H-k stacking method and by jointly inverting the receiver functions with Rayleigh wave phase velocities. Preliminary results show an average Moho depth of 40 km and an average Vp/Vs ratio of 1.72. Little evidence is found for magmatic underplating beneath the Rungwe Volcanic Province.

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