Below is the Earthquake Report Poster for this series of earthquakes. I plot the moment tensors for the M 6.2 and M 6.0 earthquakes. I also include the Modified Mercalli Intensity (MMI) contours. The MMI is a qualitative measure of shaking intensity. More on the MMI scale can be found here<\/a> and here<\/a>. I interpret these earthquakes to be right-lateral strike-slip earthquakes because of the proximity to the MTL. There is also a left lateral strike-slip fault system along the south east part of Kyushu, so this is also possible. \nCurrent tectonic situation of Japan and key tectonic features.\n<\/p><\/blockquote>\n<\/ul>\n \nFocal mechanism plots for earthquakes in southwest Japan from 1997-2006. Based on CMT solutions from the JMA catalogue (data from http:\/\/www.fnet.bosai.go.jp).\n<\/p><\/blockquote>\n<\/ul>\n \nActive faults in southwest Japan from the Active Fault Research Centre\u2019s active fault database (http:\/\/www.aist.go.jp\/RIODB\/activefault\/cgi-bin\/index.cgi). The faults are color coded by sense of movement (green = dextral; blue = normal, red = reverse, yellow = sinistral).\n<\/p><\/blockquote>\n<\/ul>\n \nActive faults in southwest Japan from the Active Fault Research Centre\u2019s active fault database (http:\/\/www.aist.go.jp\/RIODB\/activefault\/cgi-bin\/index.cgi). The faults are color coded by sense of movement (green = dextral; blue = normal, red = reverse, yellow = sinistral).\n<\/p><\/blockquote>\n<\/ul>\n I put together an animation that shows the earthquake epicenters in Japan from 1900-2016\/04\/01. I include earthquakes with magnitude \u2265 6.0. Below is a screenshot of all these earthquakes, followed by the video. Here is the kml<\/a> that I made using a USGS earthquake query. Here is the query<\/a> that I used. The animation has an additional cross section showing the Japan trench, where the 2011\/03\/11 Tohoku-Oki M 9.0 subduction zone earthquake occurred. Here is a summary of the observations made following that 2011 earthquake<\/a>.<\/p>\n
\nThere is a legend that shows how moment tensors can be interpreted. Moment tensors are graphical solutions of seismic data that show two possible fault plane solutions. One must use local tectonics, along with other data, to be able to interpret which of the two possible solutions is correct. The legend shows how these two solutions are oriented for each example (Normal\/Extensional, Thrust\/Compressional, and Strike-Slip\/Shear). There is more about moment tensors<\/a> and focal mechanisms<\/a> at the USGS.<\/p>\n\nI include some inset maps.<\/p>\n
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