Yosemite Rock Slide

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Yosemite Rock Slide
By Sarah Snedaker
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What is a rock slide?

• Free fall of pieces of rock from a cliff face or
  mountain.
• Size of rocks can vary from sand to boulders.
• The rocks and debris collects at the base of the
  slope, or talus.
• Ice wedging is main contributor to rock slides.
• Over time, cracks have been so widened that
  gravity takes over and pieces of rock fall.

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Yosemite National Park Rock Slide

• chunks of granite fell to the ground at 7 am on
  Wed. October 8th, 2008
• destroyed trees and and about 4-6 cabins
• awakened to what sounded like thunder and what
  felt like the earth crumbling apart
• three people were treated and released,
  including a child
• rock slide was the second in two days
• volume of rock was estimated at about 1,800 cubic
  yards, or about 180 truck loads

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Yosemite National Park Rock Slide

• rocks fell in an area that used to be a trail but
  is no longer kept up because of the frequent rock
  falls
• geologists have hypothesized a few reasons for
  the cracks on the cliff1) pressure from water
  flowing beneath the surface
• and 2) tree roots growing down into cracks
  wedging apart sheets of rock.

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Sources

• http//earthsci.org
• http//ap.google.com
• http//geology.com