Videos

The effects of deglaciation on the slope stability of glacial valleys have increasing importance in the context of climate change, with a role on the susceptibility to large-volume rock slides or rock avalanches and catastrophic cascading geohazards.

Wildfire often amplifies the likelihood and magnitude of debris flows in steep terrain. In arid climates (e.g. US Mountain West and Southwest), post-fire debris flows typically occur during the first rains following fire, suggesting that rainfall-driven erosion is a strong control on in-channel preconditioning and triggering of these hazards.

Atmospheric rivers (ARs) are transient channels of intense horizontal water vapor transport in the lower atmosphere.

The development of a Geologic Hazards Program for the USDA Forest Service is a challenging undertaking.

Debris flows occur as a result of glacial outburst floods or intense fall storms prior to snow accumulations and occur commonly at the glaciated Mount Rainier, WA. Over 60 such events have been documented since 1928, 35+ of which have occurred in Tahoma Creek on the southwest side of the park.

This video provides a brief overview of the Prince William Sound Landslide Hazards Project in Alaska. The video describes each of the congressional mandates that makes up the project tasks. This is the first video in a series about the project.

In the Barry Arm fjord of Alaska, repeat, high-resolution aerial and satellite data provide a unique opportunity to learn how a large bedrock landslide with a receding and thinning glacier at the toe is deforming.

How debris flows erode and deposit material along their paths is difficult to determine in natural settings due to the lack of warning and the rapid pace at which they occur. Post-event field measurements or controlled flume experiments are commonly used to evaluate debris flows between the head and the distalmost deposit.

The Washington Geological Survey works to increase public and scientific understanding of landslide hazards in Washington State. One of the ways that we do this is through use of interpretive maps, illustrations, and other types of graphics. I will show several examples of these products and will discuss some of the methods used to construct them.

Gravity Never Sleeps - Landslide Science and Risk Reduction 

By Jonathan Godt, USGS Landslide Hazards Program Coordinator 

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While California has been known to experience a fire-flood cycle for about a century, post-fire flood and debris-flow risks are increasing due to increases in the frequency and intensity of wildfires and storms and urbanization in fire- and flood-prone areas.

A range of flow types can be observed in steep, recently-burned terrain, but predicting the spatial distribution of debris flows resulting from a single storm event remains challenging.

Optical remote sensing observations of the 2019 Ridgecrest, California, earthquake sequence revealed a significant amount of surface ejecta in the nearby Searles Lake, including one area where the surface ejecta was arranged in a repeating hexagonal “honeycomb” pattern.

In the mid-1980s, Art Schultz (USGS, ret.) drew on experiences in the Colorado Front Range to identify numerous large, stratigraphically intact, kilometer-scale bedrock landslides on interbedded sandstone-shale dip slopes in the Virginia Valley and Ridge.

Wyoming’s diverse topography is host to a wide range of landslide types, density, and susceptibility. Landslides are common in multiple regions of the state, and several high-profile events in the past decade have damaged property, disrupted transportation corridors, and led to substantial economic loss.

The recently published landslide inventory for most landslide-prone areas in Minnesota provides the basis for generation of landslide susceptibility maps. These maps are derived from logistic regression analysis of mapped landslide occurrences, terrain characteristics, and Quaternary geological mapping.

This video serves as a virtual fieldtrip to document the debris flow activity following the Grizzly Creek Fire in the Glenwood Canyon, CO, USA. The Grizzly Creek Fire initiated in August 2020, and widespread destructive debris flow activity followed the during the summer of 2021.

Post-fire debris flows are often observed during the first rainy season following a wildfire, but it is unclear how long the elevated threat of debris flow persists. We constrained a hydrologic model using field and remotely sensed measurements of soil-infiltration capacity, vegetation cover, runoff, and debris-flow activity.

Heavy rainfall on the afternoon of August 3, 2022 triggered a debris flow in the Hermits Peak-Calf Canyon burn area.  A USGS monitoring station installed in the drainage basin captured video footage of the flow.  This clip of the video shows the flow from 13:43:00 MDT to 13:45:32 MDT.

0:00 (13:43 MDT) Start of Video

During the late Oligocene to early Miocene, the Marysvale volcanic field of southwestern Utah experienced three consecutive, catastrophic, mega-scale collapse events: the Sevier, Markagunt, and Black Mountains gravity slides, which we refer to collectively as the Marysvale gravity slide complex (MGSC).

Landslides display a broad spectrum of speeds for incompletely known reasons. Sliding occurs along slickensided undulatory shear surfaces within boundary shear gouge comprising clay mineral and non-clay (granular) particle mixtures, similar to tectonic fault gouge.