Here is a map showing the region and today’s earthquake epicenters. I placed the moment tensor for the M = 7.5 earthquake on the map. The moment tensor shows a pure thrust\/reverse mechanism. I placed a general tectonic map from the USGS Open File Report 1103.
\nI placed a moment tensor \/ focal mechanism legend in the upper right corner of the map. 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.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_interpretation.jpg\")
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\nThis is a local map, the three small orange circles are the earthquakes with a M = 4 range listed above. From left to right, M = 4.8, 4.4, 4.7. The large orange circle is the M = 7.5
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_local_map.PNG\")
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\nHere is a more detailed tectonic map of the region from Molnar (2001).
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/molnar_2001_plate_tectonics_fig_2.PNG\")
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\nThis map, from the USGS OFR 1103<\/a> shows the tectonic domains of Afghanistan. Todays seismicity occurred in the Hindu Kush.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/usgs_ofr_fig_3.PNG\")
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\nThis map shows historic earthquakes in the region, with magnitudes greater than or equal to M = 7.0, from 1900 until today. These are the queries that I used to make this map (kml<\/a>) (csv<\/a>). I also include the MMI contours. Here is the USGS event kmz file<\/a>.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_regional_map_historic.PNG\")
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\nThe PAGER report, which is a model based estimate of casualties and damage, suggest that there is a 32% probability that between 1,000 and 10,000 people will suffer death.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/onepager.jpg\")
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\nThis is the “Did You Feel It?” map, showing observations of felt shaking intensity, using the Modified Mercalli Shaking Intensity Scale<\/a>.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/us10003re5_ciim.jpg\")
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\nThis is another version of the DYFI data, showing how it compares to the MMI estimates that are based on a computer model.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_regional_map_dyfi.PNG\")
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\nHere is an interesting plot that shows how the shaking intensity and ground motions decay (attenuate) with distance. The orange and green lines are the modeled data (using regressions from the eastern US and California, respectively). Interestingly, the observational data (green dots) match more closely the eastern US regressions, but also generally lie between the two models. The PAGER alert is based upon these models, while the “DYFI” map is based on real observations.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/us10003re5_plot_atten.jpg\")
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\nThe USGS finite fault plane solution shows that there were two major slip patches in this earthquake.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/10003re5_slip2.png\")
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\nThe moment rate plot (shows the energy released during the earthquake with time) shows a bimodal release. This matches the slip model above.
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/mr.png\")
<\/a><\/p>\n\nJascha Polet<\/a> has produced some excellent seismicity plots, including moment tensors. Below are two maps and a cross section prepared in GMT. Dr. Polet is a Seismologist and Professor of Geophysics at Cal Poly Pomona.<\/p>\n
\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_historic_seismicity_mt_small_scale_j_polet.jpg\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_historic_seismicity_mt_large_scale_j_polet.jpg\")
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\n![\"\"](\"http:\/\/earthjay.com\/earthquakes\/20151026_afghanistan\/20151026_afghanistan_historic_seismicity_section_mt_j_polet.jpg\")
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References<\/h2>\n