Wednesday, May 7, 2008

Staring into the Abyss #3 - Yosemite as you (maybe) have never seen it

If you go back to my original post and series debut of the under-rated places of Yosemite Valley, you will remember the classic view of Yosemite Valley from the Wawona Tunnel exit. This picture is looking west from Taft Point on the rim of the valley back towards the Tunnel View, with the Cathedral Rocks and Spires forming the dominant cliffs in the center of the photo.

El Capitan Meadow is visible on the valley floor. One of the most prominent Tioga Stage glacial moraines lies just west of the meadow. It dates to about 13,000 years before present. For thousands of years, natural wildfires and intentional burnings by Native-Americans cleared the conifers from the valley floor, and over time it evolved into an open oak woodland with wide meadows and a few widely scattered conifer trees. The size of meadows in Yosemite Valley has dramatically decreased in the past century. Josiah Whitney and his crew calculated meadow area in 1866 to be 745 acres. By 1937, meadow area had dwindled to 327 acres. Today, meadows cover 65 acres, leaving only 6.8% of the original 1866 meadow area. With the advent of national park status, fires were suppressed and the shade-loving conifers flourished. The forest is now dense with young trees, and the possibility of disastrous wildfires is very real.

The distant skyline shows the relatively gentle westward slope of the mountain range, leading into the Central Valley. The mountains have risen by fault motions on the eastern margin of the range, leading to a westward tilt that has mostly developed within the last 9-10 million years.

1 comment:

Lost Geologist said...

What I am most amazed about in each of your posts are the wonderful fotos from yosemite. They are awesome!