{"id":29270,"date":"2018-02-05T10:55:39","date_gmt":"2018-02-05T16:55:39","guid":{"rendered":"http:\/\/stateimpact.npr.org\/oklahoma\/?p=29270"},"modified":"2018-02-05T13:59:05","modified_gmt":"2018-02-05T19:59:05","slug":"new-research-limiting-volume-and-depth-of-disposal-wells-key-in-reducing-oklahoma-earthquakes","status":"publish","type":"post","link":"https:\/\/stateimpact.npr.org\/oklahoma\/2018\/02\/05\/new-research-limiting-volume-and-depth-of-disposal-wells-key-in-reducing-oklahoma-earthquakes\/","title":{"rendered":"New Research: Limiting Volume And Depth Of Disposal Wells Key In Reducing Oklahoma Earthquakes"},"content":{"rendered":"<div id=\"attachment_29283\"  class=\"wp-caption module image right\" style=\"max-width: 620px;\"><a class=\"fancybox\" title=\"A tanker truck at an oil and gas production site in southeastern Oklahoma.\" href=\"https:\/\/stateimpact.npr.org\/oklahoma\/files\/2018\/02\/20180125-rig-fire-pics001_WEB.jpg\" rel=\"\"><img decoding=\"async\" loading=\"lazy\" class=\"size-large wp-image-29283\" alt=\"A tanker truck at an oil and gas production site in southeastern Oklahoma.\" src=\"https:\/\/stateimpact.npr.org\/oklahoma\/files\/2018\/02\/20180125-rig-fire-pics001_WEB-620x413.jpg\" width=\"620\" height=\"413\" \/><\/a><\/p>\n<p class=\"wp-media-credit\">Joe Wertz \/ StateImpact Oklahoma<\/p>\n<p class=\"wp-caption-text\">A tanker truck at an oil and gas production site in southeastern Oklahoma.<\/p>\n<\/div><p>Oklahoma experienced a dramatic drop in earthquakes in 2017 \u2014 a decline likely due, in part, to regulations limiting activity at oil-field disposal wells, scientists and experts say. New research suggests those regulations might be reducing some quakes more than others.<\/p><p><!--more--><\/p><p>It\u2019s been two years since state oil and gas regulators adopted a broad regional plan that limits the amount of wastewater pumped into disposal wells in quake-prone areas. The good news: It appears to be working. After peaking in 2015, earthquakes became a lot less frequent.<\/p><p><iframe loading=\"lazy\" src=\"https:\/\/docs.google.com\/spreadsheets\/d\/e\/2PACX-1vSGEdbtjy4vpk9kJJAtinyGdV1FRlWCq0jExF74jZL9YUollYm37i_LxDZO3ksDoEdEIUNm0EMI_pvw\/pubchart?oid=1167855389&format=interactive\" height=\"400\" width=\"620\"><\/iframe><\/p><p>The troubling news: The next year, Oklahoma had a pair of strong earthquakes, including the largest ever recorded, the <a href=\"https:\/\/stateimpact.npr.org\/oklahoma\/2016\/09\/08\/oklahoma-sets-a-new-earthquake-record-as-aftershocks-jolt-residents-researchers-and-regulators\/\">5.8-magnitude Pawnee quake<\/a>.<\/p><p>\u201cThe spatial relationship with the small magnitude earthquakes is being affected by the volume reductions, but not necessarily the large magnitude earthquakes,\u201d says Ryan Pollyea, an assistant professor at Virginia Tech University who studied this disparity in <a href=\"https:\/\/pubs.geoscienceworld.org\/gsa\/geology\/article-abstract\/525806\/geospatial-analysis-of-oklahoma-usa-earthquakes?redirectedFrom=fulltext\">a January paper<\/a> published in the journal <i>Geology<\/i>.<\/p><p>Pollyea\u2019s paper suggests pressure on smaller faults tapers off faster than pressure on larger faults \u2014 the ones that produce stronger shaking when they slip. The research also linked wastewater disposal to earthquake activity up to <i>75 <\/i>miles away. That finding could mean a good practice for limiting larger earthquakes could be much larger volume limits in a lot more oil fields.<\/p><p>Oklahoma earthquakes also appear to be concentrated at certain depths. The injection of wastewater into crystalline \u201cbasement\u201d rock has long been considered a risk factor for triggering shaking and is disallowed in permits issued to disposal wells operators.<\/p><p>In <a href=\"http:\/\/science.sciencemag.org\/content\/early\/2018\/01\/31\/science.aap7911\">a separate paper<\/a> published in the journal <i>Science<\/i>, a different team of researchers found that limiting the depth of injection wells might also reduce the frequency of earthquakes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Oklahoma experienced a dramatic drop in earthquakes in 2017 \u2014 a decline likely due, in part, to regulations limiting activity at oil-field disposal wells, scientists and experts say. New research suggests those regulations might be reducing some quakes more than others.<\/p>\n","protected":false},"author":36,"featured_media":29283,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[490],"tags":[500,238],"acf":[],"_links":{"self":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/29270"}],"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=29270"}],"version-history":[{"count":21,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/29270\/revisions"}],"predecessor-version":[{"id":29292,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/posts\/29270\/revisions\/29292"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/media\/29283"}],"wp:attachment":[{"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/media?parent=29270"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/categories?post=29270"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stateimpact.npr.org\/oklahoma\/wp-json\/wp\/v2\/tags?post=29270"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}