Below is my interpretive map that shows the epicenter, along with the shaking intensity contours. These contours use the Modified Mercalli Intensity (MMI) scale. The MMI is a qualitative measure of shaking intensity. More on the MMI scale can be found here<\/a> and here<\/a>. This is based upon a computer model estimate of ground motions, different from the “Did You Feel It?” estimate of ground motions that is actually based on real observations.<\/p>\n I placed a moment tensor \/ focal mechanism legend on the poster. There is more material from the USGS web sites about moment tensors<\/a> and focal mechanisms<\/a> (the beach ball symbols). Both moment tensors and focal mechanisms are solutions to seismologic data that reveal two possible interpretations for fault orientation and sense of motion. One must use other information, like the regional tectonics, to interpret which of the two possibilities is more likely. Because there are no mapped faults to give me a clue as to which slip plane this earthquake may have occurred on, it is equivocal. However, the faults to the west, which are mapped as normal (extensional) faults, may have some strike-slip faults associated with them. If this earthquake is related in that way, the right-lateral shear across the plate boundary here would suggest that this M 5.9 earthquake was along a north-south striking fault, with a right-lateral sense of motion.<\/p>\n \nThe Afro-Arabian rift system (continental graben and depressions are shaded) (From: Baker et al., 1972)\n<\/p><\/blockquote>\n \nHypsographic DEM of the East African rift system. Black lines: main faults; E\u2013W dotted lines: locations of cross-sections of Fig. 3; white surfaces: lakes; grey levels from dark (low elevations) to light (high elevations). The East African rift system is a series of several thousand kilometers long aligned successions of adjacent individual tectonic basins (rift valleys), separated from each other by relative shoals and generally bordered by uplifted shoulders. It can be regarded as an intra-continental ridge system comprising an axial rift.\n<\/p><\/blockquote>\n \nWestern branch and part of eastern branch of the East African rift system, on shadowed DEM.\n<\/p><\/blockquote>\n \nOn-going individualization of the Somalian plate in Eastern Africa. Asthenospheric intrusions (black polygons) show already open lithosphere. White arrows show direction of relative divergent movement.\n<\/p><\/blockquote>\n \nFault and fold zone of the Tanganyika\u2013Rukwa\u2013Malawi segment of the EARS. Folds are developed in stripes between left-stepping en echelon dextral strike-slip faults. This pattern of folds explains why some segment border areas of the Tanganyika rift form low plains instead of the usual high shoulders.\n<\/p><\/blockquote>\n<\/ul>\n\nI include some inset figures.<\/p>\n
\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/20160910_tanzania_interpretation.jpg\")
<\/a><\/p>\n\nHere are some of the figures on their own. I include the original figure captions below them as blockquotes.<\/p>\n
\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/Saemundsson_2010_east_africa_rift_fig_2.JPG\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/chorowicz_2005_the_east_african_rift_system_fig_1.JPG\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/chorowicz_2005_the_east_african_rift_system_fig_7.JPG\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/chorowicz_2005_the_east_african_rift_system_fig_16.JPG\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20160910_tanzania\/chorowicz_2005_the_east_african_rift_system_fig_17.JPG\")
<\/a><\/p>\n\nReferences<\/p>\n