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<p class="MsoNormal">Hi Everyone,<o:p></o:p></p>
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<p class="MsoNormal">Please join us for a seminar this week by Sean Lahusen. See details below.<o:p></o:p></p>
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<p class="MsoNormal" style="background:white;vertical-align:baseline"><b><span style="font-size:8.0pt;font-family:"Palatino Linotype",serif;color:#174E86;border:none windowtext 1.0pt;padding:0in">Francis Kevin Rengers, Ph.D. | Geomorphologist </span></b><span style="font-size:8.0pt;font-family:"Arial",sans-serif;color:#222222"><o:p></o:p></span></p>
<p class="MsoNormal" style="background:white;vertical-align:baseline"><b><span style="font-size:8.0pt;font-family:"Palatino Linotype",serif;color:#174E86">U.S. Geological Survey | Research Geologist </span></b><span style="font-size:8.0pt;font-family:"Arial",sans-serif;color:#222222"><o:p></o:p></span></p>
<p class="MsoNormal" style="background:white;vertical-align:baseline"><b><span style="font-size:8.0pt;font-family:"Palatino Linotype",serif;color:#174E86">1711 Illinois St. Golden, CO 80401 </span></b><span style="font-size:8.0pt;font-family:"Arial",sans-serif;color:#222222"><o:p></o:p></span></p>
<p class="MsoNormal" style="background:white;vertical-align:baseline"><b><span style="font-size:8.0pt;font-family:"Palatino Linotype",serif;color:#174E86">office: 303-273-8637 | cell: 720-618-0351</span></b><span style="font-size:8.0pt;font-family:"Arial",sans-serif;color:#222222"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:8.0pt;font-family:"Palatino Linotype",serif;color:#174E86"><a href="https://www.usgs.gov/staff-profiles/francis-rengers"><span style="color:#0563C1">https://www.usgs.gov/staff-profiles/francis-rengers</span></a></span></b><o:p></o:p></p>
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<p class="MsoNormal"><b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">"Thomas, Matthew A" <matthewthomas@usgs.gov><br>
<b>Date: </b>Monday, October 12, 2020 at 7:54 AM<br>
<b>Subject: </b>LHP Seminar, this Wed. (Oct. 14th): Dr. Sean Lahusen presenting "Deep-seated landslide susceptibility and triggering in the Oregon Coast Range"<o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black">Hi Folks,</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black"> </span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black;background:white">The <span class="markqotgowvms"><b>LHP</b></span><b> <span class="markutqavjo88">Seminar</span></b> will meet (virtually, via Microsoft Teams) this week on<b> Wednesday,
October 14th @ 1500</b> <b>Mountain </b>(MDT).</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
<p style="background:white"><span style="font-size:12.0pt;color:#201F1E"> </span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:#201F1E"><a href="https://www.linkedin.com/in/sean-lahusen-b251306b/" title="https://www.linkedin.com/in/sean-lahusen-b251306b/">Dr. Sean Lahusen</a> from the U.S. Geological
Survey will be presenting, “Deep-seated landslide susceptibility and triggering in the Oregon Coast Range”:</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-size:12.0pt;color:black;background:white">The Tyee Formation of the central Oregon Coast Range (OCR) hosts thousands of deep-seated landslides that fundamentally shape the morphology of the landscape
and pose a significant risk to the residents of coastal Oregon. Despite the proximity of the OCR to the Cascadia Subduction Zone megathrust, recent work suggests that rainfall, not large magnitude earthquakes, is the predominant trigger of bedrock landslides
here. Previous research has shown landslide areal density increases to the north, where the ratio of siltstone to sandstone is highest. Our new manually mapped landslide inventory has revealed even more complexity: landslide density ranges from 0-13% of total
area from west to east. To test whether lithology or structure can explain these patterns, we have started to analyze sedimentology, bedding attitudes, and estimated rock mass strength at dozens of sites across a 25x70 km east-west swath of the Tyee Mountain
Member of the Tyee Formation. Preliminary findings suggest regions of high landslide density tend to be underlain by bedrock with a greater overall ratio of siltstone to sandstone, corroborating previous work in the region. Bedding thickness, which cannot
be explained by siltstone ratio alone, also seems to be important. Regions with few to no deep-seated landslides are often underlain by the thickest sandstone beds, while regions with high landslide density tend to have thicker siltstone beds. Our study reveals
higher variability in landslide density across the Tyee Mountain member than previously recognized that is likely due to changes in lithological properties within the same mapped geology. We argue that landslide susceptibility models could be improved by accounting
for greater detail in lithologic properties within generalized geologic units.</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black;background:white">Hope you can join us!</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:#201F1E"> </span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span class="markutqavjo88"><b><span style="font-size:10.0pt;color:#201F1E">Seminar</span></b></span><b><span style="font-size:10.0pt;color:#201F1E"> Connection Instructions:</span></b><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:10.0pt;color:#201F1E">-- Turn your VPN services off.</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:10.0pt;color:#201F1E">-- Join in via Microsoft Teams by <a href="https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fteams.microsoft.com%2Fdl%2Flauncher%2Flauncher.html%3Furl%3D%252f_%2523%252fl%252fmeetup-join%252f19%253ameeting_NmU4M2E3ZDktNmIwOS00Y2NkLWEyZmMtNGM3YTQwYjQxYTFm%2540thread.v2%252f0%253fcontext%253d%25257b%252522Tid%252522%25253a%2525220693b5ba-4b18-4d7b-9341-f32f400a5494%252522%25252c%252522Oid%252522%25253a%25252282b4c0ea-89e9-402c-8d2a-8f68ffac5319%252522%25257d%2526anon%253dtrue%26type%3Dmeetup-join%26deeplinkId%3D354c7d10-e11c-4bfa-9af2-9aee09c70a3f%26directDl%3Dtrue%26msLaunch%3Dtrue%26enableMobilePage%3Dfalse%26suppressPrompt%3Dtrue%23&data=02%7C01%7Cdon.lindsay%40conservation.ca.gov%7Ceb46b0e08e5a46e16e4008d8483d3f4f%7C4c5988ae5a0040e8b065a017f9c99494%7C0%7C0%7C637338775182060975&sdata=IkdKqk%2B850RhUB0mOBpac0TTS8zySWDpmlMGcE4kDpg%3D&reserved=0" target="_blank" title="https://teams.microsoft.com/dl/launcher/launcher.html?url=%2f_%23%2fl%2fmeetup-join%2f19%3ameeting_NmU4M2E3ZDktNmIwOS00Y2NkLWEyZmMtNGM3YTQwYjQxYTFm%40thread.v2%2f0%3fcontext%3d%257b%2522Tid%2522%253a%25220693b5ba-4b18-4d7b-9341-f32f400a5494%2522%252c%2522">clicking
here</a>.</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:#201F1E"> </span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black">Take care,</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p style="background:white"><span style="font-size:12.0pt;color:black">matt</span><span style="font-size:12.0pt;font-family:"Times New Roman",serif;color:#201F1E"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt">Matthew A. Thomas</span></b><span style="font-size:12.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt">Research Hydrologist (Mendenhall Fellow)</span><span style="font-size:12.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;color:black;background:white">1711 Illinois Street, Golden, CO 80401</span><span style="font-size:12.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;color:black;background:white">office: 303-273-8588 </span><span style="font-size:12.0pt"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;color:black;background:white">cell: 720-417-9021<br>
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<p class="MsoNormal"><span style="font-size:12.0pt"><a href="https://www.usgs.gov/staff-profiles/matthew-a-thomas" title="https://www.usgs.gov/staff-profiles/matthew-a-thomas"><span style="font-size:10.0pt;background:white">USGS</span></a></span><span style="font-size:10.0pt"> |
</span><span style="font-size:12.0pt"><a href="https://www.researchgate.net/profile/Matthew_Thomas27" title="https://www.researchgate.net/profile/Matthew_Thomas27"><span style="font-size:10.0pt">ResearchGate</span></a></span><span style="font-size:10.0pt">
| <a href="https://scholar.google.com/citations?user=Hg7I2YcAAAAJ&hl=en" title="https://scholar.google.com/citations?user=Hg7I2YcAAAAJ&hl=en">
Google Scholar</a></span><span style="font-size:12.0pt"><o:p></o:p></span></p>
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