Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California

Wieczorek, Gerald F.; Snyder, James B.; Waitt, Richard B.; Morrissey, Meghan M.; Uhrhammer, Robert A.; Harp, Edwin L.; Norris, Robert D.; Bursik, Marcus; Finewood, Lee G.

doi:10.1130/0016-7606(2000)112<0075:ujrfah>2.3.co;2

Cited by 16 publications

(43 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, the sliding velocity of the historical Goldau slide of 1806 and Elm slide of 1881 was estimated to be 70 m s −1 , and the peak sliding velocity of the Val Pola landslide of 1987 in the Italian Alp was estimated to range between 76 and 108 m s −1 [ Crosta et al , 2004, and references therein]. The impact velocity of the 1996 Happy Isles, Yosemite National Park, California, rockfall is estimated to be 110–120 m s −1 [ Wieczorek et al , 2000, and references therein]. All these slides are significantly smaller than the HML and they all slid shorter distances, although on steeper slopes.…”

Section: Discussionsupporting

confidence: 88%

The long runout of the Heart Mountain landslide: Heating, pressurization, and carbonate decomposition

2010

View full text Add to dashboard Cite

[1] The Heart Mountain landslide of northwestern Wyoming is the largest subaerial landslide known. This Eocene age slide slid ∼50 km along a shallow 2°slope, posing a long-standing enigma regarding its emplacement mechanism. We suggest here a mechanism for the catastrophic emplacement of the Heart Mountain landslide that is independent of slide triggering. The mechanism is a feedback between shear heating, thermal pressurization, and thermal decomposition of carbonates at the slide shear zone. Such a feedback arises when a porous, fluid-filled shear zone heats up because of frictional sliding. If the shear zone is confined, the generated heat leads to pore pressure rise, which in turn reduces frictional resistance to sliding, leading to acceleration. Temperatures at the shear zone quickly reach the decomposition temperature of carbonates. Since the shear zone of the Heart Mountain slide is located within a dolomite layer, it is expected that thermal decomposition of dolomite occurred within the Heart Mountain shear zone. This prediction is supported by ample field evidence for carbonate decomposition during the emplacement. Simulation of the sliding dynamics of the Heart Mountain block, accounting for feedback between shear heating, thermal pressurization, and thermal decomposition of carbonates, successfully reproduce the travel distance of the Heart Mountain block. The simulation results also predict that the maximum sliding velocity ranged between tens of meters per second to more than 100 m s −1 (depending on model assumptions) and that the duration of sliding was of the order of a few tens of minutes, in agreement with previous assessments.

show abstract

Section: Discussionsupporting

confidence: 88%

The long runout of the Heart Mountain landslide: Heating, pressurization, and carbonate decomposition

2010

View full text Add to dashboard Cite

show abstract

“…The geological contacts in this area may have contributed to slope failure, as noted elsewhere (Weidinger and Korup, 2009). The eastern flank of Glacier Point has experienced several historical (A.D. 1857 to present) rock falls (Stock et al, 2013), including an ,30,000 m 3 rock fall on 10 July 1996 that devastated the Happy Isles area with an air blast and dense sandy cloud (Wieczorek et al, 2000).…”

Section: Hypothesis 4: Rock Fall Depositmentioning

confidence: 99%

Supporting Evidence for a 9.6 1 ka Rock Fall Originating from Glacier Point in Yosemite Valley, California

Cordes

Stock

Schwab

et al. 2013

Environmental & Engineering Geoscience

View full text Add to dashboard Cite

Large boulders exceeding 10 m 3 in exposed volume are widely scattered throughout Upper Pines Campground in eastern Yosemite Valley, Yosemite National Park, California. These enigmatic boulders rest up to 330 m from the base of adjacent talus slopes but lack geomorphic expressions typical of other large rock fall, debris flow, or glacial deposits in Yosemite. We evaluated four hypotheses for boulder deposition: (1) glacial deposition during ice retreat 15-17 ka, (2) fluvial deposition during a high-discharge flood event, (3) debris flow deposition, and (4) rock fall deposition. We utilized field mapping, spatial analysis, cosmogenic 10 Be exposure dating, and X-ray fluorescence analysis to investigate possible modes of deposition. A mean boulder exposure age of 9.6 ± 1 ka considerably postdates glacial retreat from Yosemite Valley, effectively ruling out glacial deposition. Discharge and bed stress calculations indicate that although flooding could have been capable of entraining boulders at confined upstream locations, it is unlikely to have transported boulders as far as the Upper Pines area. Slope comparisons and evaluation of surface morphology of debris flow fans in Yosemite Valley suggest that the boulders did not result from debris flows. Geochemical

show abstract

“…11.1). Major triggers include frost shattering (Gardner, 1983;Matsuoka and Sakai, 1999;Arosio et al, 2013), seismic shaking (Bull et al, 1994;Bull and Brandon, 1998;Wieczorek et al, 2000;Vidrih et al, 2001), and human activity (Barnard et al, 2001;Brunsden, 2001). The separation of mass occurs along discontinuities, such as fractures, joints, and bedding planes or along weak surfaces in soil, such as cracks.…”

Section: Falls (Gravity-driven)mentioning

confidence: 99%

A Review of Mass Movement Processes and Risk in the Critical Zone of Earth

Regmi

Giardino

McDonald

et al. 2015

Developments in Earth Surface Processes

View full text Add to dashboard Cite

Unusual July 10, 1996, rock fall at Happy Isles, Yosemite National Park, California

Cited by 16 publications

References 0 publications

The long runout of the Heart Mountain landslide: Heating, pressurization, and carbonate decomposition

The long runout of the Heart Mountain landslide: Heating, pressurization, and carbonate decomposition

Supporting Evidence for a 9.6 1 ka Rock Fall Originating from Glacier Point in Yosemite Valley, California

A Review of Mass Movement Processes and Risk in the Critical Zone of Earth

Contact Info

Product

Resources

About