Preliminary Locations of Landslides and Snow Avalanches Triggered by the 2025 M7.0 Hubbard Glacier Earthquake

This data release contains preliminary point locations of potential landslides and snow avalanches triggered by the M7.0 Hubbard Glacier Earthquake based on a Synthetic Aperture Radar (SAR) change map by Eiden (2025). This SAR change map was the first publicly available post-event radar or optical dataset covering the earthquake region. The map reflects changes in the backscattering properties of the surface by comparing Sentinel-1 SAR acquisitions from before (November 28, 2025) and after (December 09, 2025) the earthquake, which occurred on December 06, 2025. Many types of surface change affect backscattering properties in snowy, mountainous environments, like that of the Hubbard Glacier region at the time of the earthquake, including landslides, snow avalanches, new snowfall, changes in surface moisture, and glacier movement (Lindsay and others 2025, Rott and Mätzler, 1987). By combining these change detection data with topographic maps and regional information, we were able to map where surface change was likely related to mass movements associated with the earthquake such as landslides and snow avalanches.
We focused on assessing the areas where the USGS near-real-time earthquake-triggered Ground Failure Product estimated landslides were likely, based on the ShakeMap shaking estimates and proxies for landslide susceptibility. The exact boundaries of the area that we assessed for ground failure are provided in shapefile format in Hubbard_LSmapping_boundary.zip. The point locations of where we detected evidence of ground failure are provided in shapefile format in Hubbard_LSlocations.zip. These points were mapped where the shape of patches of increased roughness aligned with the topography in a way that was consistent with gravitational flow behavior. For example, we would expect the footprints of roughness change to typically be elongated perpendicular to elevation contour lines, as would be typical of a landslide or snow avalanche. We found we could primarily detect changes in roughness due to the deposition of snow, ice, or rock onto glaciers and could not see changes in the source areas. Therefore, we placed the location points at the most uphill portion of the patch of increased roughness based on a reference topography map.
The “interpretation” attribute (which is labeled as “interpreta” in the “Hubbard_LSlocations” file due to character limits) contains a numbered code corresponding to our interpretation of each mapped location and its certainty as follows:
1 (probable large landslide or snow avalanche): the shape of the patch of increased roughness and its alignment with topography is consistent with a large landslide or snow avalanche that is at least 2 km long and shows well-defined boundaries.
2 (probable smaller landslide or snow avalanche): the patch of increased roughness is sufficiently well-defined and away from areas of noise or poor data quality such that we are relatively certain it reflects a mass movement of some type, but it is small enough (less than 2 km long) that it could be either a landslide or a snow avalanche.
3 (increase in surface roughness of undetermined origin): this level is assigned to patches that are, in most cases, aligned with topography in a way typical of a mass movement, but may have less well-defined edges (for example, speckled), may be smaller or similar in character to noise nearby, or may be hard to distinguish from adjacent areas with low data quality. This category also includes areas of increased roughness on tributary glaciers for which the origin is unclear. These changes may, for example, reflect changes to the glacier itself (for example movement, snow bridge or serac collapse) or mass movement deposits originating from adjacent areas.
We note that the direction of satellite movement combined with the look angle of the satellite means we are not able to reliably detect changes on steep southwestern and western-facing slopes due to foreshortening. Therefore, mass movements are likely less comprehensively mapped on southwest- and west-facing aspects.
For more information about the landslide response to the Hubbard Glacier earthquake, see the associated USGS landslide response webpage and the Hubbard Glacier ScienceBase landing page. For more information about the earthquake, refer to the USGS earthquake event page.