<?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>Frederick Pollitz</dc:contributor>
  <dc:contributor>Thorne Lay</dc:contributor>
  <dc:contributor>Han Yue</dc:contributor>
  <dc:creator>Katherine A. Guns</dc:creator>
  <dc:date>2021</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;The Queen Charlotte-Fairweather Fault (QC-FF) system off the coast of British Columbia and southeast Alaska is a highly active dextral strike-slip plate boundary that accommodates ∼50&amp;nbsp;mm/yr of relative motion between the Pacific and North America plates. Nine&amp;nbsp;&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;&lt;i&gt;W&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;&amp;nbsp;≥&amp;nbsp;6.7 earthquakes have occurred along the QC-FF system since 1910, including a&amp;nbsp;&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;&lt;i&gt;S&lt;/i&gt;(G-R)&lt;/sub&gt;&lt;span&gt;8.1 event in 1949. Two recent earthquakes, the October 28, 2012 Haida Gwaii (&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;&lt;i&gt;W&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;7.8) and January 5, 2013 Craig, Alaska (&lt;/span&gt;&lt;i&gt;M&lt;/i&gt;&lt;sub&gt;&lt;i&gt;W&lt;/i&gt;&lt;/sub&gt;&lt;span&gt;7.5) events, produced postseismic transient deformation that was recorded in the motions of 25 nearby continuous Global Positioning System (cGPS) stations. Here, we use 5+&amp;nbsp;yr of cGPS measurements to characterize the underlying mechanisms of postseismic deformation and to constrain the viscosity structure of the upper mantle surrounding the QC-FF. We construct forward models of viscoelastic deformation driven by coseismic stress changes from these two earthquakes and explore a large set of laterally heterogeneous viscosity structures that incorporate a relatively weak back-arc domain; we then evaluate each model based on its fit to the postseismic signals in our cGPS data. In determining best-fit model structures, we additionally incorporate the effects of afterslip following the 2012 event. Our results indicate the occurrence of a combination of temporally decaying afterslip and vigorous viscoelastic relaxation of the mantle asthenosphere. In addition, our best-fit viscosity structure (transient viscosity of 1.4–2.0&amp;nbsp;×&amp;nbsp;10&lt;/span&gt;&lt;sup&gt;18&lt;/sup&gt;&lt;span&gt;&amp;nbsp;Pa&amp;nbsp;s; steady-state viscosity of 10&lt;/span&gt;&lt;sup&gt;19&lt;/sup&gt;&lt;span&gt;&amp;nbsp;Pa&amp;nbsp;s) is consistent with the range of upper mantle viscosities determined in previous studies of glacial isostatic rebound and postseismic deformation.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1029/2021JB021891</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>American Geophysical Union</dc:publisher>
  <dc:title>Exploring GPS observations of postseismic deformation following the 2012 MW7.8 Haida Gwaii and 2013 MW7.5 Craig, Alaska Earthquakes: Implications for viscoelastic Earth structure</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>