Mussel Rock, at the park that used to be the Colma dump. DSC_0420 : 無料・フリー素材/写真
Mussel Rock, at the park that used to be the Colma dump. DSC_0420 / wbaiv
| ライセンス | クリエイティブ・コモンズ 表示-継承 2.1 |
|---|---|
| 説明 | John McPhee describes this spot in "Assembling California". (Up in this picture is more or less North, West is off to the left. ) Stand at the small inlet low, but not at the bottom, of the right side. Just above where the surf is. About where the path from the corner of the parking lot ends. From the shore, looking at the backward "C" shaped patch of bare earth, you can see the rock under the earth. It's cracked vertically. Up and down. This is the San Andreas Fault. (its blurred in this picture by the hot exhaust of a jet engine.) The fault is much wider, of course, and deeper. But this is part of it too. This is where it meets the Pacific ocean. It runs under the ocean up to Drake's Bay, comes ashore again, and goes to Tomales Bay. Put a ruler on a map from Tomales Bay back to Crystal Springs Resevior. Its a straight line, and crosses the coast about here.Mussel Rock, the big one offshore, is not the same as the rock on either side of the fault. It came from somewhere South, got caught *in* the Fault and has been carried along for many, many miles, over thousands if not millions of years.The Pacific Plate, to the West (left), is sliding North (up). It's ocean floor that has come East from a spreading center under the Pacific. Its also sliding under the California Plate, so it moves a bit to the East (right) as well. When it gets deep enough under the western edge of North America, it re-melts and the result are the volcanoes from the Central Valley up through Oregon and Washington. Mt. Shasta, for example. Or St. Helens. Or Rainier. The California plate is the accumulated debris from the ocean floor, and volcanic islands that formed on that ocean floor, that's been scraped off onto the West edge of North America. The east edge of the California plate is the Sierra Nevada mountains, the steep (Eastern) faces are the edge. The gentle, Western, slope, of the Sierra, shows how the plate has been tilted up in the East, down in the West. |
| 撮影日 | 2014-07-09 16:29:41 |
| 撮影者 | wbaiv |
| タグ | |
| 撮影地 | 地図 |
| カメラ | NIKON D40X , NIKON CORPORATION |
| 露出 | 0.001 sec (1/800) |
| 開放F値 | f/14.0 |
| 焦点距離 | 55 mm |