Landslides in the United States cause approximately $3.5 billion in
damage, and kill between 25-50 people annually. The largest landslide in modern U.S. history (in terms of
volume) was most likely one that occurred in 2013 in Bingham
Canyon outside of Salt Lake City,
Utah. It had a slide mass of 55 million cubic meters (compared to an estimated
10 million cubic meters during the Oso event in 2014,
see image below). Fortunately, no one was injured or killed during the Utah
slide.
Landslides impact
California’s terrain often. These are generally related to precipitation
patterns, in particular if there has been previous months of drought
conditions. Early this year, across Southern California, heavy rain was
causing numerous mudslides
and road closures in burn scar areas from recent wildfires. The image
below clearly shows what type of enormous devastation we are talking about [the
death toll was 20]. That area was previously burned by the Thomas
fire, the biggest wildfire in CA’s recorded history, so it is not
surprise that heavy rain provoked this mudslides, as the soil had no holding
vegetation left. It is very possible this will repeat in the state later in the
year after the big storms/rain hit.
This USGS page has information on how to identify landslides and what to do if one happens. If you want to know if you are living in a risk area, you can access maps like the USGS below that shows the Emergency Assessment of Post-Fire Debris-Flow Hazards.





