Mount Meager, a glaciated volcano in a changing cryosphere: hazards and risk challenges
Mount Meager is a glacier-clad volcanic complex in British Columbia, Canada. It is known for its landslides, of which the 2010 is the largest Canadian historical landslide. In my PhD thesis I investigated slope instability processes at Mount Meager and the the ongoing deglaciation that is affecting them. The results of my thesis and the relative peer-review publication are listed below:
The first chapter of the thesis deals with the application of Structure from Motion (SfM) to historic photography to document glacier and landslide activity at Mount Meager, and the value of historic 3D topographic reconstruction for scientific and dissemination value purposes.
Rheological evolution of the Mount Meager 2010 debris avalanche, southwestern British Columbia
Then, we described the 2010 Mount Meager landslide deposit to interpret emplacement dynamics and kinematics. The 2010 landslide separated in water-rich and water-poor phases that had different runout and distinct deposits. This flow separation has important hazard and risk consequences.
Precursory slope distress prior to the 2010 Mount Meager landslide, British Columbia
We analyzed historic airphotos to constrain the slope deformation prior to the 2010 collapse. The glacier near the toe of the slope retreated in the failure lead-up, and the collapse evolved in four sub-failures involving the whole volcanic sequence. The total failure volume is estimated at 53 ± 3.8 millions of cubic meters of material.
Water in volcanoes: evolution, storage and rapid release during landslides
We estimated 6 million of cubic meters of water in the slope, that allowed the separation of the frontal water-rich phase.
Landslides and glacier retreat at Mt. Meager volcano: hazard and risk challenges
We identified 27 large (more than five hundred thousands of cubic meters) unstable slopes at Mount Meager and calculated ~1.3 cubic kilometers of ice loss since 1987. The west flank of Plinth peak and Devastation Creek valley moved up to -34±10 mm and -36±10 mm, respectively, over a 24-day period during the summer of 2016. The failure of these slopes could impact infrastructures and communities downstream of the volcano.
The resulting decompression on the volcanic edifice after the failure of Plinth peak would affect the stress field to a depth of 6 km and up to 4 MPa. This sudden decompression could lead to hydrothermal or magmatic eruptions.
The results of this works have been featured by major media outlets and let to many follow up project, including the monitoring of Mount Meager volcano.
