Dynamic Imaging of Glacier Structures at High‐Resolution Using Source Localization With a Dense Seismic Array

Ugo Nanni (1) , Philippe Roux (2) , Florent Gimbert (1) , Albanne Lecointre (2)

1 IGE - Institut des Géosciences de l’Environnement
2 ISTerre - Institut des Sciences de la Terre

Dense seismic array monitoring combined with advanced processing can help retrieve and locate a variety of seismic sources with unprecedented resolution and spatial coverage. We present a methodology that goes beyond classical localization algorithms through gathering various types of sources (impulsive or continuous) using a single scheme based on a gradient-descent optimization and evaluating different levels of phase coherence. We apply our methodology on an Alpine glacier and demonstrate that we can retrieve the dynamics of active crevasses with a metric resolution using sources associated with high phase coherence; the presence of diffracting materials (e.g., rocks) trapped in transverse crevasses using sources with moderate phase coherence; and the two-dimensional time evolution of the subglacial hydrology system using sources with low phase coherence. Our study highlights the strength of using an appropriate and systematic seismological approach to image a wide range of subsurface structures and phenomena in settings with complex wavefields.

Domaines: Glaciologie; Géophysique [physics.geo-ph]

Ugo Nanni, Philippe Roux, Florent Gimbert, Albanne Lecointre. Dynamic Imaging of Glacier Structures at High‐Resolution Using Source Localization With a Dense Seismic Array. Geophysical Research Letters, 2022, 49 (6), pp.e2021GL095996. ⟨10.1029/2021gl095996⟩. ⟨hal-03613797⟩