<?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:creator>Arthur D. Frankel</dc:creator>
  <dc:date>2022</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Strong‐motion recordings of the 2014&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-5-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-21" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-22" class="mrow"&gt;&lt;span id="MathJax-Span-23" class="msub"&gt;&lt;span id="MathJax-Span-24" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-25" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;8.2 Iquique and 2015&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-6-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-26" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-27" class="mrow"&gt;&lt;span id="MathJax-Span-28" class="msub"&gt;&lt;span id="MathJax-Span-29" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-30" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;8.3 Illapel, Chile, earthquakes were analyzed to determine rupture propagation and the location, timing, and strength of subevents that produce most of the high‐frequency (≥1&amp;nbsp;Hz) ground motions. A moving window,cross‐correlation analysis of recordings from a local dense array, band‐pass filtered at 1&amp;nbsp;Hz, directly shows that the Iquique earthquake ruptured to the southeast over a distance of about 60&amp;nbsp;km. Array analysis of lower frequency energy (0.03–0.1&amp;nbsp;Hz) indicates that it occurred updip of the high‐frequency rupture. A methodology was developed for inverting the envelopes of acceleration records (1–5&amp;nbsp;Hz) to map high‐frequency source factors on the rupture zone and was applied to the two earthquakes. Waveforms of&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-7-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-31" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-32" class="mrow"&gt;&lt;span id="MathJax-Span-33" class="msub"&gt;&lt;span id="MathJax-Span-34" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-35" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;6 earthquakes were used as empirical Green’s functions in the inversions. High‐frequency subevents within the two&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-8-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-36" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-37" class="mrow"&gt;&lt;span id="MathJax-Span-38" class="msub"&gt;&lt;span id="MathJax-Span-39" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-40" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;8 earthquakes were located at depths ranging from 25 to 55&amp;nbsp;km and mostly occurred downdip of the peak slip of these earthquakes. Fourier spectral ratios of the Iquique mainshock with respect to&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-9-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-41" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-42" class="mrow"&gt;&lt;span id="MathJax-Span-43" class="msub"&gt;&lt;span id="MathJax-Span-44" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-45" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;5–6 aftershocks were fit to determine their stress drops. The stress drops were roughly constant from&amp;nbsp;&lt;/span&gt;&lt;span class="inline-formula no-formula-id"&gt;&lt;span id="MathJax-Element-10-Frame" class="MathJax" data-mathml="&lt;math xmlns=&amp;quot;http://www.w3.org/1998/Math/MathML&amp;quot;&gt;&lt;msub xmlns=&amp;quot;&amp;quot;&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;mi mathvariant=&amp;quot;normal&amp;quot;&gt;w&lt;/mi&gt;&lt;/msub&gt;&lt;/math&gt;"&gt;&lt;span id="MathJax-Span-46" class="math"&gt;&lt;span&gt;&lt;span id="MathJax-Span-47" class="mrow"&gt;&lt;span id="MathJax-Span-48" class="msub"&gt;&lt;span id="MathJax-Span-49" class="mi"&gt;M&lt;/span&gt;&lt;span id="MathJax-Span-50" class="mi"&gt;w&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span class="MJX_Assistive_MathML"&gt;Mw&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&amp;nbsp;5 to 8 at 10–20&amp;nbsp;MPa. A compound rupture model is described in which subevents occur in areas of spatially heterogeneous strength and stress on the rupture, and produce the high‐frequency radiated energy of the overall earthquake, but are not located in the areas of peak slip. The stress drop of the overall earthquake is shown to equal the root mean square stress drop of subevents averaged over the rupture area.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1785/0120210331</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Seismological Society of America</dc:publisher>
  <dc:title>High‐frequency rupture processes of the 2014 Mw 8.2 Iquique and 2015 Mw 8.3 Illapel, Chile, earthquakes determined from strong‐motion recordings</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>