You double back along the water, south to Mussel Rock. Mussel Rock is a horse. As any geologist will tell you, a horse is a displaced rock mass that has been caught between the walls of a fault. This one appeared to have got away. It seemed to have strained successfully to jump out of the continent. Or so I thought the first time I was there. It loomed in fog. Green seas slammed against it and turned white. It was not a small rock. It was like a three-story building, standing in the Pacific, with brown pelicans on the roof. You could walk out on a ledge and look up through the fog at the pelicans. When you looked around and faced inland, you saw that you were at the base of a fifty-foot cliff, its lithology shattered beyond identification. A huge crack split the cliff from top to bottom and ran on out through the zakelijke energie vergelijken ledge and under the waves. After a five-hundred-mile northwesterly drift through southern and central California, this was where the San Andreas Fault intersected the sea. I went to Mussel Rock that foggy afternoon in i978 with the geologist Kenneth Deffeyes. I have returned a number of times since, alone or in the company of others. With regard to the lithosphere, it’s a good place to sit and watch the plates move. It is a moment in geography that does your thinking for you. The San Andreas Fault, of course, is not a single strand. It is something like a wire rope, as much as half a mile wide, each strand the signature of one or many earthquakes. Mussel Rock is near the outboard edge of the zone. You cannot really say that on one side of the big crack is the North American Plate and on the other side is the Pacific Plate, but it’s tempting to zakelijke energie do so. Almost automatically, you stand with one foot on each side and imagine your stride lengtheningyour right foot, say, riding backward toward Mexico, your left foot in motion toward Alaska. There’s some truth in such a picture, but the actual plate boundary is not so sharply defined. Not only is the San Andreas of varying width in its complexity of strands, it is merely the senior fault in a large family of more or less parallel faults in an over-all swath at least fifty miles wide. Some of the faults are to the west and under the ocean; more are inland.