Japan Geoscience Union Meeting 2016

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International Session (Oral)

Symbol M (Multidisciplinary and Interdisciplinary) » M-TT Technology & Techniques

[M-TT05] Cryoseismology - a new proxy for detecting surface environmental variations of the Earth -

Thu. May 26, 2016 10:45 AM - 12:15 PM 202 (2F)

Convener:*Masaki Kanao(National Institute of Polar Research), Seiji Tsuboi(JAMSTEC, Center for Earth Information Science and Technology), Takeo Ito(Earthquake and Volcano Research Center, Graduate School of Environmental Studies, Nagoya University), Douglas Wiens(Washington University in St Louis), Sridhar Anandakrishnan(Penn State University), Jeremy Winberry(Central Washington University), Kent Anderson(Incorporated Research Institutions for Seismology), Chair:Genti Toyokuni(Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University), Takeo Ito(Earthquake and Volcano Research Center, Graduate School of Environmental Studies, Nagoya University)

11:15 AM - 11:45 AM

[MTT05-02] Repeating Glacial Earthquakes Reveal Migration of Subglacial Sticky-spots.

★Invited papers

*Jeremy Paul Winberry1, Audrey D Huerta1, Howard Conway2, Sridhar Anandakrishnan4, Richard Aster3, Michelle Koutnik2, Andrew Nyblade4, Douglas Wiens5 (1.Central Washington University, 2.University of Washington, 3.Colorado State University, 4.Pennsylvania State University, 5.Washington University in Saint Louis)

Keywords:ice sheet, repeating earthquake, glacier

Many glaciers primarily dissipate their gravitational potential energy by sliding along the ice-bedrock interface. In such cases, a glacier’s driving stress is often balanced by regions of enhanced basal traction known as sticky-spots. While the role of sticky-spots in the force budget of glaciers and ice streams has long been recognized, their formation remains less well understood. In this presentation, we leverage recent advances in seismograph coverage in the Transantarctic Mountains (TAM) to study relatively large glacial seismic events (> M2) that can be observed at regional distances. We report on 5 newly discovered and one previously studied sequences of repeating glacial earthquakes. These new sequences reveal that families can remain active for up to 7 years. Additionally, by tracking subtle changes in relative arrival times as well as waveform similarity, we deduce that these sticky-spots originate from migrating bands of basal debris.