Videos

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.

Building and maintaining a landslide hazards program as a state agency presents many opportunities and challenges.

Landslide susceptibility is commonly assessed using physics-based slope stability models. However, modeling the three-dimensional (3D) mechanics of discrete landslides, on a regional scale, remains challenging.

California is one of the most geologically diverse states in the nation, the second most seismically active, and first in seismic risk with a population approaching 40 million.

Landslide initiation processes in subarctic Alaska are complicated by the prevalence of ice-rich permafrost. Permafrost and permafrost thaw influence landslide type, frequency, and continued ground surface deformation, resulting in positive feedbacks between permafrost thaw and landsliding.

The granitic cliffs of Yosemite Valley produce frequent rockfalls, modifying the landscape but also posing risk to park visitors. Analyses of terrestrial lidar and historical structure-from-motion photogrammetry data provide relatively precise short-term (approximately 40 years) rates of rockfall and cliff retreat.

Understanding of rockfall frequency-magnitude relationships is important for managing rockfall hazards, but characterizing these relationships is a challenging problem due to limited data, limited access, and the difficulty of accurately dating historic rockfalls.

The 92-mile, dead-end Denali Park Road crosses an accelerating rock glacier. Until 2014, the rock glacier would only displace the road a few tens of centimeters per year, however during the summer of 2021 the rock glacier has moved the road almost 40 cm/day.

Snow avalanches kill, on average, 27 people in the United States each year and impact infrastructure and commerce in mountainous areas.

We sometimes fall back on an implicit model that post-wildfire debris flows are only triggered once a certain level of saturation or rainfall is reached, and that the sediment supply is soon exhausted and future flows are unlikely until it recharges.

The Santa Lucia Mountains of the Big Sur coast, California contain abundant active landslides.

The record 2018 wet year in Pittsburgh resulted in widespread landslides throughout the region, many of which caused considerable damage to residential property and transportation infrastructure.

A broad overview of landslide geology across Pennsylvania, and historical and current work on landslides by the Pennsylvania Survey and others. The diverse geology and topography of Pennsylvania's woods provides a variety of landslide problems beyond the well-known issues around Pittsburgh.

Calwood burn area, Calwood post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:06 MDT to 14:13:05 MDT.

Calwood burn area, Heil Ranch post-fire debris-flow monitoring station video footage from rainstorm on July 31, 2021 from 14:07 MDT to 14:13:11 MDT.

Rock-mass strength is typically assumed to influence geomorphic processes by setting the erodibility of landscapes. However, the contribution of rock-mass strength to topographic form is often overlooked, largely because rock-mass strength is challenging to quantify over the broad spatial scales relevant to geomorphology.

In 2015, the Washington Geological Survey received legislative funding to start a Landslide Hazards Program (LHP). The LHP has three primary functions: landslide inventory mapping, post-wildfire debris flow assessments, and emergency response.