{"id":2519,"date":"2015-05-24T13:45:46","date_gmt":"2015-05-24T21:45:46","guid":{"rendered":"http:\/\/earthjay.com\/?p=2519"},"modified":"2015-05-24T13:45:46","modified_gmt":"2015-05-24T21:45:46","slug":"santa-cruz-western-pacific-earthquake-swarm","status":"publish","type":"post","link":"https:\/\/earthjay.com\/?p=2519","title":{"rendered":"Santa Cruz (western Pacific) Earthquake Swarm!"},"content":{"rendered":"<p>The past couple of days have brought us a series of large magnitude strike-slip earthquakes along a plate boundary between the Solomon Trench and the New Hebrides Trench. I posted about the first earthquake <a href=\"http:\/\/earthjay.com\/?p=2511\" target=\"_blank\" rel=\"noopener\">here<\/a> and <a href=\"http:\/\/earthjay.com\/?p=2496\" target=\"_blank\" rel=\"noopener\">here<\/a>. This swarm of earthquakes, along with the other recent seismic activity along this system, supports the hypothesis that this is a strike-slip plate boundary (nor a subduction zone as plotted on some maps).<br \/>\nHere is a map that I put together. I plot the epicenters of the earthquakes, along with the moment tensors for the three largest magnitude earthquakes. I also place a transparent focal mechanism over the swarm, showing the sense of motion for this plate boundary fault. Technically, transform plate boundaries are strike-slip (shear) plate boundary fault systems that connect spreading ridges. SO, I would like to call this a transform plate boundary fault system, but need to see if it really satisfies the definition that people use&#8230; I&#8217;ll get back to us on this&#8230;<br \/>\nI also note that these three largest earthquakes happen in a time order from east to west, unzipping the fault over three +- days. I label them in order (1, 2, 3) and place an orange arrow depicting this temporal relation). Very cool!<br \/>\n<a href=\"http:\/\/earthjay.com\/earthquakes\/20150522_santa_cruz\/20150522_santacruz_local_interpretation.pdf\" target=\"_blank\" rel=\"noopener\"><br \/>\n<img decoding=\"async\" src=\"http:\/\/earthjay.com\/earthquakes\/20150522_santa_cruz\/20150522_santacruz_local_interpretation.jpg\" width=\"100%\" alt=\"\" \/><\/a><\/p>\n<ul>\nHere are the USGS web pages for the three largest earthquakes in this series:<\/p>\n<li>2015.05.20 <a href=\"http:\/\/earthquake.usgs.gov\/earthquakes\/eventpage\/us10002b03#general_summary\" target=\"_blank\" rel=\"noopener\">Mw 6.8<\/a><\/li>\n<li>2015.05.22 <a href=\"http:\/\/earthquake.usgs.gov\/earthquakes\/eventpage\/us10002bnk#general_summary\" target=\"_blank\" rel=\"noopener\">Mw 6.9<\/a><\/li>\n<li>2015.05.22 <a href=\"http:\/\/earthquake.usgs.gov\/earthquakes\/eventpage\/us10002bpw#general_summary\" target=\"_blank\" rel=\"noopener\">Mw 6.8<\/a><\/li>\n<\/ul>\n<p>Here is an updated regional map with all of the epicenters from this swarm plotted. Below I link to an earlier map with more notations on it.<br \/>\n<a href=\"http:\/\/earthjay.com\/earthquakes\/20150522_santa_cruz\/20150522_santacruz_regional_map.PNG\" target=\"_blank\" rel=\"noopener\"><br \/>\n<img decoding=\"async\" src=\"http:\/\/earthjay.com\/earthquakes\/20150522_santa_cruz\/20150522_santacruz_regional_map.PNG\" width=\"100%\" alt=\"\" \/><\/a><br \/>\n<a href=\"http:\/\/earthjay.com\/earthquakes\/20150521_solomon\/20150521_solomon_interpretation.pdf\" target=\"_blank\" rel=\"noopener\"><br \/>\n<img decoding=\"async\" src=\"http:\/\/earthjay.com\/earthquakes\/20150521_solomon\/20150521_solomon_interpretation.jpg\" width=\"100%\" alt=\"\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<div class=\"entry-summary\">\nThe past couple of days have brought us a series of large magnitude strike-slip earthquakes along a plate boundary between the Solomon Trench and the New Hebrides Trench. I posted about the first earthquake here and here. This swarm of&hellip;\n<\/div>\n<div class=\"link-more\"><a href=\"https:\/\/earthjay.com\/?p=2519\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &ldquo;Santa Cruz (western Pacific) Earthquake Swarm!&rdquo;<\/span>&hellip;<\/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":[44,49,6,7,9,13,27,33,37],"tags":[],"aioseo_notices":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/posts\/2519"}],"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=2519"}],"version-history":[{"count":0,"href":"https:\/\/earthjay.com\/index.php?rest_route=\/wp\/v2\/posts\/2519\/revisions"}],"wp:attachment":[{"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2519"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2519"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/earthjay.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2519"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}