<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>James William Atterholt</dc:contributor>
  <dc:contributor>Andrew J. Barbour</dc:contributor>
  <dc:contributor>Jeanne L. Hardebeck</dc:contributor>
  <dc:creator>Robert J. Skoumal</dc:creator>
  <dc:date>2025</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Distributed acoustic sensing (DAS), which transforms a fiber optic cable into an array of high frequency strainmeters, has the potential to help us characterize earthquakes with a dense sampling of measurements. While earthquake focal mechanisms are frequently determined using&amp;nbsp;&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;-wave polarities and&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;/&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;&amp;nbsp;amplitude ratios with inertial seismometers, the dense sampling of DAS over potentially large portions of the focal sphere can aid our solutions. Here, we consider ∼200 regional earthquakes and thousands of&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;/&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;&amp;nbsp;measurements on a DAS cable colocated with a network of inertial seismometers near Arcata, California. We demonstrate the&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;/&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;&amp;nbsp;ratio measurements made on DAS are similar to those made on the inertial seismometers and can be used to constrain focal mechanism solutions.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/2025GL116373</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Geophysical Union</dc:publisher>
  <dc:title>S/P amplitude ratios with Distributed Acoustic Sensing and application to earthquake focal mechanisms</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>