Geology topics

Paola Reichenbach

Publications and source records attributed to Paola Reichenbach.

3 recordsLinked to original sources

USGS2014

Quantitative rock-fall hazard and risk assessment for Yosemite Valley, Yosemite National Park, California

Rock falls are common in Yosemite Valley, California, posing substantial hazard and risk to the approximately four million annual visitors to Yosemite National Park. Rock falls in Yosemite Valley over the past few decades have damaged structures and caused injuries within developed regions located on or adjacent to talus slopes highlighting the need for additional investigations into rock-fall hazard and risk. This assessment builds upon previous investigations of rock-fall hazard and risk in Yosemite Valley and focuses on hazard and risk to structures posed by relatively frequent fragmental-type rock falls as large as approximately 100,000 (cubic meters) in volume.

California↗

USGS2011

Rock fall simulation at Timpanogos Cave National Monument, American Fork Canyon, Utah, USA

Rock fall from limestone cliffs at Timpanogos Cave National Monument in American Fork Canyon east of Provo, Utah, is a common occurrence. The cave is located in limestone cliffs high on the southern side of the canyon. One fatality in 1933 led to the construction of rock fall shelters at the cave entrance and exit in 1976. Numerous rock fall incidents, including a near miss in 2000 in the vicinity of the trail below the cave exit, have led to a decision to extend the shelter at the cave exit to protect visitors from these ongoing rock fall events initiating from cliffs immediately above the cave exit. Three-dimensional rock fall simulations from sources at the top of these cliffs have provided data from which to assess the spatial frequencies and velocities of rock falls from the cliffs and to constrain the design of protective measures to reduce the rock fall hazard. Results from the rock fall simulations are consistent with the spatial patterns of rock fall impacts that have been observed at the cave exit site.

Utah↗

USGS2007

Staircase Falls Rockfall on December 26, 2003, and Geologic Hazards at Curry Village, Yosemite National Park, California

Since 1857, several hundred rockfalls, rockslides, and debris flows have been observed in Yosemite National Park. At 12:45 a.m. on December 26, 2003, a severe winter storm triggered a rockfall west of Glacier Point in Yosemite Valley. Rock debris moved quickly eastward down Staircase Falls toward Curry Village. As the rapidly moving rock mass reached talus at the bottom of Staircase Falls, smaller pieces of flying rock penetrated occupied cabins. Physical characterization of the rockfall site included rockfall volume, joint patterns affecting initial release of rock and the travel path of rockfall, factors affecting weathering and weakening of bedrock, and hydrology affecting slope stability within joints. Although time return intervals are not predictable, a three-dimensional rockfall model was used to assess future rockfall potential and risk. Predictive rockfall and debris-flow methods suggest that landslide hazards beneath these steep cliffs extend farther than impact ranges defined from surface talus in Yosemite Valley, leaving some park facilities vulnerable.

Open-File Report↗