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<p class="MsoNormal"><span style="font-size:14.0pt">I’m sending this message to alert the whole IGS community about the physical cause of this event, and to point you to additional information – keep watching the COMET site for more news.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Since late December, there has been a significant westward displacement of the IGS site ADIS, approaching ~20 mm so far, which is caused by a large volcanic intrusion that is more than 100 km distant. The
westward displacement appears to be detectable by around 20 December, but became much larger around 24 December. This corresponds to a rapid lengthening of the dike intrusion, which has now reached about 50 km in length and extends between Fentale and Dofen
volcanoes. Data for this mostly comes from InSAR, and you can see some beautiful interferograms in the reports at the link below.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Juliet Biggs at the University of Bristol noted<o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:14.0pt">“</span></i><i><span style="font-size:14.0pt;color:black">We've been putting together a series of event response reports through the crisis, which you might be interested in:<span class="apple-converted-space"> </span></span></i><i><span style="font-size:14.0pt"><a href="https://urldefense.com/v3/__https:/comet.nerc.ac.uk/publications/event-response-reports/__;!!HXCxUKc!1DfNSwpw4jrkCuJ3AHfblo65zB5fEVXNHEQ9PWzYkUq_C38vVEYZ9-ylbtEASlIPxNQjTNVaVurH8TPdPyAG7toQFuE$" title="https://urldefense.com/v3/__https:/comet.nerc.ac.uk/publications/event-response-reports/__;!!HXCxUKc!1DfNSwpw4jrkCuJ3AHfblo65zB5fEVXNHEQ9PWzYkUq_C38vVEYZ9-ylbtEASlIPxNQjTNVaVurH8TPdPyAG7toQFuE$"><span style="color:purple">https://comet.nerc.ac.uk/publications/event-response-reports/</span></a><span style="color:black">.
The intrusion seems to have ended for now, but we never know if there will be another phase.”</span></span></i><i><span style="font-size:14.0pt"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">The larger displacement corresponds to a particular phase in the event, which they describe in their January 14<sup>th</sup> report, and show in Figure 2f,g of that report.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:14.0pt;color:black">“Between 24<span class="s1">th</span></span></i><span class="apple-converted-space"><i><span style="color:black"> </span></i></span><i><span style="font-size:14.0pt;color:black">and 29<span class="s1">th</span></span></i><span class="apple-converted-space"><i><span style="color:black"> </span></i></span><i><span style="font-size:14.0pt;color:black">December,
there was a change in direction, accompanied by an acceleration in dyke propagation. The dyke tip propagated about 24 km in 5 days (Fig 2f,g) and reached the neighbouring volcano Dofen, 47 km to the north of Fentale. The direction of the dyke changes from
radial to Fentale to aligned with the rift axis (~020°). LOS deformation associated with dyke opening is ~36 cm.”</span></i><span style="font-size:14.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">Jeff<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">--------------<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:black">Dr. Jeffrey T. Freymueller<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:black">Endowed Chair for Geology of the Solid Earth<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:black">Department Chair<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:black">Dept. of Earth and Environmental Sciences<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;color:black">Michigan State University<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt">URL: <a href="https://msu.edu/~freymuel/">
<span style="color:#0563C1">https://msu.edu/~freymuel/</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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