BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CiviCRM//NONSGML CiviEvent iCal//EN X-WR-TIMEZONE:America/Chicago METHOD:PUBLISH BEGIN:VEVENT UID:CiviCRM_EventID_2671_d3319be4f90071e87b81b1178ed41494@www.hgs.org SUMMARY:The 27th Annual Robert E. Sheriff Lecture DESCRIPTION:The 27th Annual Robert E. Sheriff Lecture\n \n Fro m Fiber-Optic Seismology to Geodesy: Operational E arly Warning and Real-Time Imaging of Volcanic Eru ptions\n \n  \;\n \n Monday\, November 10\n \n Norris Conference Center &bull\; \;816 Town a nd Country Blvd #210\n \n Social Hour and poster v iewing 5:00 &ndash\; 6:30 PM\n \n Dinner 6:30&ndas h\;7:30 PM\, Presentations 7:30 - 9:00 PM\n \n Reg istration closes November 9 at noon.\n \n  \;\ n \n https://www.uh.edu/nsm/earth-atmospheric/news -events/sheriff-lecture/\n \n  \;\n \n Abstrac t: \n \n Fiber-optic sensing technologies\, partic ularly Distributed Acoustic Sensing (DAS)\, are tr ansforming geophysics by repurposing existing fibe r-optic cables into dense arrays of strain sensors . This approach enables long-range\, long-duration \, and cost-effective monitoring across diverse en vironments. By exploiting the ultra-dense sampling of the seismic wavefield along telecommunication cables\, fiber-optic seismology has advanced high- resolution seismic source characterization and sub surface imaging. \;\n \n Recently\, we introdu ced fiber-optic geodesy\, a method that leverages low-frequency DAS (LFDAS) recordings to monitor qu asi-static ground deformation caused by magma intr usions. Compared to conventional ground- or satell ite-based geodetic measurements\, fiber-optic geod esy offers lower noise levels and higher spatiotem poral resolutions\, enabling real-time monitoring and imaging of magmatic processes. \n \n We applie d this approach to the ongoing eruption sequence n ear Grindaví\;k\, southwest Iceland\, throug h two phases of DAS deployments. In the first phas e (Nov 2023 to Nov 2024)\, we converted a 100-km t elecom cable into a DAS array. Distinct LFDAS sign als consistently emerged tens of minutes before ea ch eruption. Since April 2024\, we have operated a n LFDAS-based early warning system in collaboratio n with the Icelandic Meteorological Office (IMO)\, successfully issuing alerts for two eruptions whi le avoiding false alarms for non-eruptive ones. Ge odetic inversions of LFDAS signals enabled unprece dented spatiotemporal resolution of magma intrusio ns. In the second phase (from Feb 2025)\, IMO depl oyed an ASN OptoDAS interrogator to monitor two te lecom cables\, with a total length of 150 km\, int egrating early warning with real-time imaging. The addition of a 50-km northern cable further improv ed azimuthal coverage and inversion resolution. \n \n These results demonstrate fiber-optic geodesy as a powerful tool for monitoring ground deformati ons. It shall find wide applications both onshore and offshore\, using existing telecommunication in frastructure or dedicated fiber deployments\n \n \ n \n  \;\n \n Dr. Jiaxuan Li\n \n \n \n Dr. Ji axuan Li joined the University of Houston as an As sistant Professor of Geophysics in January 2025. P rior to this appointment\, he was a Postdoctoral S cholar at the California Institute of Technology ( 2020&ndash\;2024). He earned his Ph.D. in Geophysi cs from the University of Houston in 2020 and his B.S. in Geophysics from Peking University in 2015. \n \n Dr. Li&rsquo\;s research focuses on applying fiber-optic sensing technologies to study seismic and geodetic processes and to image subsurface st ructures across diverse environments\, including c rustal\, volcanic\, and glacial settings. His broa der interests also encompass geothermal energy dev elopment\, carbon sequestration monitoring\, and t he dynamics of deep earthquakes.\n \n  \;\n \n  \; CATEGORIES:Meeting CALSCALE:GREGORIAN DTSTAMP;VALUE=DATE-TIME:20251110T170000 DTSTART;VALUE=DATE-TIME:20251110T170000 DTEND;VALUE=DATE-TIME:20251110T210000 LOCATION:Norris Conference Center\n 816 Town & Country Blvd .\, Suite 210\n Houston\, TX 77024\n United States \n URL:https://www.hgs.org/civicrm/event/info?reset=1&id=2671 END:VEVENT END:VCALENDAR