Seminar by Ugo Nanni (Dept of Geosciences, University of Oslo):
Spatio-temporal evolution of the hydro-mechanical feedback during a glacier surge build-up derived from seismic observations.
Abstract: Glacier surge initiation is caused by the interplay between ice flow, basal friction and subglacial drainage conditions, yet still poorly understand. This study aims at constraining the hydro-mechanical feedback at play during the surge intitiation of Kongsvegen glacier in Svalbard. We deployed 20 geophones from the glacier front to its equilibrium line altitude, and from the glacier surface to its bed and derive the spatio-temporal evolution of subglacial drainage system and icequake activity spanning five years. By co-locating instruments at the surface and at the bed of the glacier, we show that subglacial drainage properties inferred from the surface integrate also supra- and eng- glacial processes leading to an overestimation of basal water pressure and an underestimation of subglacial drainage capacity. Additionally, we identify a temporal increase in crevasse and stick-slip phenomena up-glacier, linking it to surge initiation through hydro-mechanical feedback.
The talk is in Aud 1 in the Geology Building. It is also possible to follow at Zoom.
Video link to the lecture will be sent to the mailing lists alle@geo and geohyd-info@geo. If you want to subscribe to the geohyd-info@geo list send an email to Anita.
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About the seminar
This seminar is offered by the Section for Geography and Hydrology (GeoHyd), Dept. of Geosciences, University of Oslo. The seminars are announced as lunch seminars so bring your lunch if you want to
The seminars are open to everyone interested, and especially students are welcome.
The Lunch Seminar Team
– Yeliz and Thomas