{"id":30268,"date":"2018-06-15T14:18:29","date_gmt":"2018-06-15T19:18:29","guid":{"rendered":"http:\/\/stateimpact.npr.org\/oklahoma\/?p=30268"},"modified":"2018-07-23T15:56:21","modified_gmt":"2018-07-23T20:56:21","slug":"researchers-may-have-found-deep-previously-unmapped-faults-that-could-be-a-source-of-oklahomas-earthquake-uptick","status":"publish","type":"post","link":"https:\/\/stateimpact.npr.org\/oklahoma\/2018\/06\/15\/researchers-may-have-found-deep-previously-unmapped-faults-that-could-be-a-source-of-oklahomas-earthquake-uptick\/","title":{"rendered":"Researchers may have found deep, previously unmapped faults that could be a source of Oklahoma\u2019s earthquake uptick"},"content":{"rendered":"<p>Previously unmapped faults in Oklahoma could be contributing to an intense uptick in earthquakes triggered by oil-field wastewater disposal, a new study suggests.<\/p><p>Scientists have <a href=\"https:\/\/stateimpact.npr.org\/oklahoma\/2015\/05\/05\/stateimpacts-earthquake-research-reading-list\/\">linked thousands of earthquakes<\/a> to the energy industry practice of pumping oil-field waste fluid into underground disposal wells in recent years, but t<a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/2018GL077768\">he new research<\/a> helps explain why much of the shaking doesn\u2019t line up with maps of known faults, most of which detail fault formations within a mile of the surface.<!--more--><\/p><p>\u201cThe problem is the earthquakes are happening from about 1 mile down to about 5 miles down,\u201d said U.S. Geological Survey research geophysicist Anaja Shah, who led the research.<\/p><p>Oklahoma fault maps are built primarily with data describing surface and sedimentary rock layers that paint an incomplete picture of fault formations in a deep layer of granite, known among geologists and oil drillers as \u201cbasement rock.\u201d<\/p><p>This granite rock, which also underlies oil and natural gas deposits, has long been scrutinized as a breeding ground for earthquakes. Oklahoma\u2019s first regulatory response to the quake boom included directing oil and gas companies ensure disposal wells weren\u2019t <a href=\"https:\/\/stateimpact.npr.org\/oklahoma\/2014\/10\/30\/hearing-on-disposal-well-rules-exposes-gaps-in-states-earthquake-response\/\">drilled into granite<\/a>, where scientists warned wastewater could agitate faults and trigger shaking.<\/p><p>The new research, published in the journal Geophysical Research Letters, is based on data collected in 2017 during a three-month aerial survey using planes outfitted with magnetic sensors.<\/p><p>Researchers used the data to identify possible faults in granite basement rock and to determine whether the findings corresponded <strong>with <\/strong>earthquake locations and known faults in shallower rock formations. The new data also suggest most faults in the deep granite layer are aligned in a particular direction \u2014 similar to wood grain.<\/p><p>\u201cWhat&#8217;s especially interesting, which we didn&#8217;t know, is that that grain is actually different from the grain of the shallow rocks,\u201d Shah said.<\/p><p>Researchers have to confirm the potentially new fault discoveries with other data, but Shaw says the orientation of faults in the deep granite layer also appears to be particularly well suited for slipping.<\/p><p>\u201cWhen you add a bit of fluid injection, that\u2019s probably what\u2019s pushing it right over the edge,\u201d she said.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Scientists have linked thousands of earthquakes to oil-field disposal wells, but new research helps explain why much of the shaking doesn\u2019t line up with maps of known faults.<\/p>\n","protected":false},"author":36,"featured_media":30273,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[490,491],"tags":[500,238],"acf":[],"_links":{"self":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/30268"}],"collection":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/users\/36"}],"replies":[{"embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/comments?post=30268"}],"version-history":[{"count":3,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/30268\/revisions"}],"predecessor-version":[{"id":30275,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/30268\/revisions\/30275"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/media\/30273"}],"wp:attachment":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/media?parent=30268"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/categories?post=30268"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/tags?post=30268"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}