Locating a complex subglacial drainage network using seismic arrays on Glacier d’Otemma, Switzerland

Journal of Glaciology, vol. 72

Abstract

Abstract Glaciers actively store and release meltwater with significant impacts on glacier flow velocity and downstream environments. The evolution of this drainage system is a key component in understanding glacier dynamics. In temperate alpine glaciers, the change of the subglacial drainage network from distributed to channelised is theoretically known, but lacks empirical documentation. As subglacial channels are extremely difficult to access, it is important to test innovative methods for locating them. Here, we use surface seismic monitoring, which enables us to identify the location of multiple subglacial channels below Glacier d’Otemma, Valais, Switzerland. We calculate time delays between pairs of seismic sensors and backtrack source locations. Using matched field processing and beamforming analysis, we obtain spatial and temporal patterns of seismic noise produced by the glacier. This allows us to interpret a possible evolution of the subglacial drainage network from a distributed to an efficient one and locate three distinct subglacial channels in close proximity.

Authors 8

1. Eva Wolf corresponding

   University of Lausanne

   Affiliation as printed

   Université de Lausanne

2. Eleonore Stutzmann

   Institut de physique du globe de Paris

   Affiliation as printed

   Institut de Physique du Globe de Paris

3. Jean‐Philippe Métaxian

   Institut de physique du globe de Paris

   Affiliation as printed

   Institut de Physique du Globe de Paris

4. Ugo Nanni

   University of Oslo

   Affiliation as printed

   University of Oslo Faculty of Mathematics and Natural Sciences

5. Floreana Miesen

   University of Lausanne

   Affiliation as printed

   Université de Lausanne

6. Matthew Jenkin

   University of Lausanne

   Affiliation as printed

   Université de Lausanne

7. Michael Dietze Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University

8. Stuart Nicholas Lane

   University of Lausanne

   Affiliation as printed

   Université de Lausanne