How Advanced Reconnaissance Answered the Question of the Haines Landslide
The Challenge: In December 2020, an unprecedented "atmospheric river" event triggered a devastating landslide in Haines, Alaska, destroying homes and killing two residents in an area thought to be safe. The urgent question for the community and for scientists was: Why did the landslide happen here, and could it have been foreseen?
RAPID staff and researcher set up long distance lidar to 3D model landslide area
A New Approach: To answer this, a research team led by Margaret M. Darrow of the University of Alaska and including RAPID Facility experts Joseph Wartman and Michael Grilliot, conducted a detailed post-disaster reconnaissance. Leveraging their expertise in advanced data collection, the team deployed to the site with state-of-the-art instrumentation, including high-resolution UAS-lidar, to create a detailed 3D model of the landslide and analyze its geomorphological characteristics.
Data & Discovery: The comprehensive analysis revealed three critical discoveries about the landslide's initiation mechanisms. First, by comparing the new 3D model to pre-existing data, the team determined the landslide was a reactivation of an ancient, massive landslide feature. Second, the source of the slide was a block of weak, fractured bedrock that was visibly displaced before the 2020 event. Third, the failure occurred along pre-existing geological fault planes, which were supercharged with water from the extreme rain-on-snow event.
Impact: The research, published in the journal Landslides, provided a definitive answer to "Why here?". It was not a random event but a predictable failure at a known, pre-existing hazard zone. The study underscores the critical importance of using advanced tools like lidar to identify paleo-landslides, which may be hidden by forests, as these are the most likely locations for future failures. The team's findings are now helping to inform regional hazard assessments and have led to recommendations for developing new warning systems that couple weather forecasts with geological hazard maps. Through the expertise of its personnel and the application of advanced reconnaissance techniques, the RAPID Facility helped transform a destructive incident into valuable insights for protecting vulnerable communities in Alaska and beyond.
Citation: Darrow, M. M., Nelson, V. A., Grilliot, M., Wartman, J., Jacobs, A., Baichtal, J. F., & Buxton, C. (2022). Geomorphology and initiation mechanisms of the 2020 Haines, Alaska landslide. Landslides, 19, 2489-2510. https://doi.org/10.1007/s10346-022-01899-3