{"id":1558,"date":"2014-04-11T00:17:51","date_gmt":"2014-04-11T08:17:51","guid":{"rendered":"http:\/\/earthjay.com\/?p=1558"},"modified":"2014-04-11T00:17:51","modified_gmt":"2014-04-11T08:17:51","slug":"panguna-papua-new-guinea-subduction-zone-earthquake","status":"publish","type":"post","link":"https:\/\/earthjay.com\/?p=1558","title":{"rendered":"Panguna, Papua New Guinea: subduction zone earthquake"},"content":{"rendered":"

This looks to have shaken people up, just by looking at the intensity map below. These are generated automatically and take some assumptions that simplify the results (so the real shaking is probably not what the shake map intensity maps show). In this region of the Solomon Sea, there is a subduction zone fault that dives to the north beneath Bouganville Island, forming the New Britain trench. The Solomon or Woodlark sub plate is subducting to the north, beneath the Bismark sub-plate, as shown in a map from Greg Corbett<\/a>.
\nThere probably was a local tsunami, but the magnitude and location are too distant to pose a tsunami hazard in northern California (especially with the configuration of the islands in this region). In 1998, ~1,500 km to the west, there was a landslide triggered by an earthquake that generated a large tsunami<\/a>.
\nHere is the USGS website<\/a> for this earthquake.
\nThis is an early moment tensor, which shows a pure compressional mechanism.
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\nThis shows the earthquake as it relates to the regional plate boundaries, islands, and Australia. Shaking intensity uses the Modified Mercalli Intensity (MMI) scale.
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\nThis shows some historic earthquakes as grey circles. Note how they align with the plate boundaries.
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\nHere is a regional view of the islands, the epicenter, and the shaking intensity:
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\nThis regional scale map shows the subduction zone fault depth contours as modeled by Dr. Gavin Hayes, from the USGS<\/a>. Hayes and his colleagues used earthquake hypocentral depths to constrain the position of the subduction zone fault. The hypocenter is listed at 50 km deep, which places it well beneath the known location for the main subduction zone fault here, but there may be some complications with the plate boundaries here. The megathrust is only ~30 km in this epicentral location.
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\nThis is the Hayes map for this region.
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\nHere is a great map that was posted to a blog. The blogger did not give credit to the person who made the map, but i found it used in this presentation<\/a> prepared by IRIS (they gave proper credit).
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\nThis is the PAGER earthquake shaking and loss estimate page for this earthquake. This earthquake gets a “green” alert. The estimated fatalities and economic losses are low, but not zero. Here is a web page with some information<\/a> about how these estimates are made.
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\nThis is a map from Australian National University<\/a> showing GPS rates in the region, along with the major plate boundaries.
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\nThis map shows the regional tectonic setting in more detail.
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\nThis map shows how McCue modeled seismic hazard for this region in 1999. Click on the map for a pdf of his paper.
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\nThis map has some of the islands and water bodies labeled.
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\nThis map shows the mainshock as a large orange circle and the first major aftershock as a red circle. Here is the USGS page<\/a> for the M 6.7 aftershock. There was a swarm of earthquakes to the northwest of today’s earthquake and they also have deep hypocenters, deeper than we would expect given the fault geometry modeled by Hayes at the USGS.
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\nHere is the moment tensor from Potsdam GEOFON Extended Virtual Network <\/a>:
\nGFZ Event gfz2014hbgl
\n14\/04\/11 07:07:23.79
\nSolomon Islands
\nEpicenter: -6.61 155.02
\nMW 7.1
\nGFZ MOMENT TENSOR SOLUTION
\nDepth 60 No. of sta: 50
\nMoment Tensor; Scale 10**19 Nm
\n Mrr= 4.58 Mtt=-2.65
\n Mpp=-1.92 Mrt= 0.95
\n Mrp=-0.89 Mtp= 2.47
\nPrincipal axes:
\n T Val= 4.75 Plg=82 Azm= 46
\n N 0.21 1 311
\n P -4.96 8 221
\nBest Double Couple:Mo=4.9*10**19
\n NP1:Strike=131 Dip=53 Slip= 91
\n NP2: 310 37 89
\n ———–
\n —————–
\n ———————–
\n ##############———–
\n –#################———-
\n —###################——-
\n —-####################——-
\n——########## #######——-
\n——########## T ########——
\n——-######### #########—–
\n——–#####################—-
\n———-###################—-
\n ———–#################—
\n ————################-
\n —————############–
\n —————–########
\n ———————–
\n —————–
\n ———– <\/p>\n","protected":false},"excerpt":{"rendered":"

\nThis looks to have shaken people up, just by looking at the intensity map below. These are generated automatically and take some assumptions that simplify the results (so the real shaking is probably not what the shake map intensity maps…\n<\/div>\n
Continue reading “Panguna, Papua New Guinea: subduction zone earthquake”<\/span>…<\/a><\/div>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[50,5,6,7,27,29,34,38],"tags":[],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/posts\/1558"}],"collection":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1558"}],"version-history":[{"count":0,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/posts\/1558\/revisions"}],"wp:attachment":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}