How did Half Dome, the massive rock monument in Yosemite National Park, acquire its unique shape?
At the head of the valley in Yosemite National Park - as if on a pedestal - stands Half Dome. It is smoothly rounded on three sides and a sheer vertical face on the fourth. Half Dome, which stands nearly 8,800 feet (2,682 meters) above sea level, is composed of granodiorite, and is the remains of a magma chamber that cooled slowly and crystallized thousands of feet beneath the Earth's surface. The solidified magma chamber - called a pluton - was then exposed by uplift and erosion of the overlying rock. As the overlying rock eroded, the confining pressure on the pluton was removed and a type of weathering called exfoliation slowly created the more rounded appearance of the dome. At the same time, weathering along vertical joints created the steep northwest face. Later glaciation continued the process by undercutting and plucking rock from the already steep face. The processes of weathering continues to this day as shown by the many rock falls which occur within Yosemite Valley.
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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...
Stock, Greg M.; Luco, Nicolas; Collins, Brian D.; Harp, Edwin L.; Reichenbach, Paola; Frankel, Kurt L.
Oblique map showing maximum extent of 20,000-year-old (Tioga) glaciers, Yosemite National Park, central Sierra Nevada, California
This map shows the alpine ice field and associated valley glaciers at their maximum extent during the Tioga glaciation. The Tioga glaciation, which peaked about 15,000-20,OOO years ago, was the last major glaciation in the Sierra Nevada. The Tuolumne ice field fed not only the trunk glacier that moved down the Tuolumne River canyon through the...
Alpha, T.R.; Wahrhaftig, Clyde; Huber, N.K.
The geologic story of Yosemite National Park
Within 150 years, Yosemite has moved from great obscurity to worldwide fame as one of the most visited of our national parks. As a remarkable place where people can enjoy unparalleled scenes of natural beauty and where many easily observed geologic features are concentrated, the park is rivaled by few other areas on the planet. The majesty and...
Huber, N. King
Geologic history of the Yosemite Valley
The problem of the origin of the Yosemite Valley inherently demands a solution in quantitative terms. Its essence is, To what extent is the valley a product of glacial action, to what extent a product of stream erosion? The principal result of the investigations upon which this report is based is the determination within narrow limits of the...
Matthes, Francois E.
Hot Days Can Trigger Yosemite Rockfalls
After more than three years of monitoring the towering granite cliffs of Yosemite National Park, scientists have new insights into a potentially important mechanism that can trigger rockfalls in the park. Although many conditions can trigger rockfalls, some rockfalls are more likely to happen in the hottest part of the day, during the hottest part of the year.
Yosemite National Park and U.S. Geological Survey Publish Quantitative Rockfall Hazard and Risk Assessment for Yosemite Valley
Yosemite National Park and USGS scientists, in collaboration with academic geologists, recently completed a comprehensive study of rockfall hazard and risk in Yosemite Valley.
Yosemite Valley
Yosemite National Park, part of the Sierra Nevada range. Credit: Alex Demas, USGS.
Scientists Collect Data on Yosemite Rock Erosion
Yosemite National Park geologist Greg Stock and USGS civil engineer Brian Collins download data from instruments measuring how much granitic exfoliation sheets move from daily temperature variations as a precursor to rock fall.
Yosemite Falls and Half Dome Panorama
In this panorama, Yosemite Falls may be seen on the left and Half Dome on the right. Yosemite Falls is the tallest known waterfall in North America, with a total plunge of 2,425 ft (739 m). Half Dome is a granite dome, part of the Sierra Nevada batholith.
Manzanita with Half Dome
In this image, a manzanita shrub may be seen with Half Dome behind it. Manzanitas are evergreen shrubs with orange or red bark.
Yosemite Falls-All Three Sections
In this image, all three sections of Yosemite Falls can be seen. Yosemite Falls is the highest measured waterfall in North America at 2,425 ft (739 m) in height. Yosemite Falls is one of the most famous waterfalls within Yosemite National Park.
Moon over Half Dome Panorama
In this image, the Moon may be seen in panorama rising over Half Dome. Half Dome is a granite dome, rising about 4,737 ft (1,444 m) above the surrounding valley. It is part of the Sierra Nevada batholith and is one of Yosemite National Park's most famous features.
Moon over Half Dome Detail
In this image, the Moon may be seen in detail rising over Half Dome. Half Dome is a granite dome, rising about 4,737 ft (1,444 m) above the surrounding valley. It is part of the Sierra Nevada batholith and is one of Yosemite National Park's most famous features.
Moon over Half Dome
In this image, the Moon may be seen rising over Half Dome. Half Dome is a granite dome, rising about 4,737 ft (1,444 m) above the surrounding valley. It is part of the Sierra Nevada batholith and is one of Yosemite National Park's most famous features.
Half Dome from Cathedral Spires
In this image, Half Dome may be seen from the base of Cathedral Spires. Half Dome is a granite dome, rising about 4,737 ft (1,444 m) above the surrounding valley. It is part of the Sierra Nevada batholith and is one of Yosemite National Park's most famous features.