<?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>J.M. Lees</dc:contributor>
  <dc:contributor>F. Monastero</dc:contributor>
  <dc:creator>S. E. Hough</dc:creator>
  <dc:date>1999</dc:date>
  <dc:description>&lt;div id="135253913" class="article-section-wrapper js-article-section js-content-section  " data-section-parent-id="0"&gt;&lt;p&gt;We use a multiple-empirical Green's function method to determine source properties of small (&lt;i&gt;M&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;−0.4 to 1.3) earthquakes and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;- and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;-wave attenuation at the Coso Geothermal Field, California. Source properties of a previously identified set of clustered events from the Coso geothermal region are first analyzed using an empirical Green's function (&lt;span class="small-caps"&gt;EGF&lt;/span&gt;) method. Stress-drop values of at least 0.5-1 MPa are inferred for all of the events; in many cases, the corner frequency is outside the usable bandwidth, and the stress drop can only be constrained as being higher than 3 MPa.&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;- and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;-wave stress-drop estimates are identical to the resolution limits of the data. These results are indistinguishable from numerous&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="small-caps"&gt;EGF&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;studies of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;2-5 earthquakes, suggesting a similarity in rupture processes that extends to events that are both tiny and induced, providing further support for Byerlee's Law. Whole-path&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Q&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;estimates for&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;P&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;S&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;waves are determined using the multiple-empirical Green's function (&lt;span class="small-caps"&gt;MEGF&lt;/span&gt;) method of Hough (1997), whereby spectra from clusters of colocated events at a given station are inverted for a single attenuation parameter, κ, with source parameters constrained from&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span class="small-caps"&gt;EGF&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;analysis. The κ estimates, which we infer to be resolved to within 0.01 sec or better, exhibit almost as much scatter as a function of hypocentral distance as do values from previous single-spectrum studies for which much higher uncertainties in individual κ estimates are expected. The variability in κ estimates determined here therefore suggests real lateral variability in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Q&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;structure. Although the ray-path coverage is too sparse to yield a complete three-dimensional attenuation tomographic image, we invert the inferred κ value for three-dimensional structure using a damped least-squares method, and the results do reveal significant lateral variability in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Q&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;structure. The inferred attenuation variability corresponds to the heat-flow variations within the geothermal region. A central low-&lt;i&gt;Q&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;region corresponds well with the central high-heat flow region; additional detailed structure is also suggested.&lt;/p&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1785/BSSA0890061606</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Seismological Society of America</dc:publisher>
  <dc:title>Attenuation and source properties at the Coso Geothermal area, California</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>