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

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.

Automated summary

Dense seismic array monitoring with advanced processing enables the retrieval and location of various seismic sources with unprecedented resolution and spatial coverage. Using a single scheme based on gradient-descent optimization and evaluating different levels of phase coherence, our methodology goes beyond classical localization algorithms by gathering different types of sources. By applying this methodology to an Alpine glacier, we demonstrate the ability to retrieve the dynamics of active crevasses, identify diffracting materials in transverse crevasses, and analyze the time evolution of the subglacial hydrology system.