Monday, April 16, 2007
Any river can flow out across a broad plain, gradually widening into an arm of the ocean, but I'm more intrigued by rivers that find their way through a range of mountains and sneak up all of a sudden on the coast. The Klamath River is one of these - typical of west coast rivers and a function of a tectonically active coastline where the hills rise faster than the rivers can cut them down. This is the spit that extends across the mouth of the river - the river exits the narrow channel at the far northern end.
This is definitely not Puget Sound! No glacial gravels, no mountains on the western horizon, and too many lines of breakers. Thursday night we camped at Patrick's Point, between Arcata and the Humboldt Lagoons, and wandered down to the beach. Great bluffs, a nice landslide, and a small stream crossing the beach. Big Lagoon is visible a few miles north, the largest and southernmost of three bays that have been cut off from the Pacific by narrow bands of sand and gravel. The waves weren't particularly big, but were still impressive. I haven't heard how El Nino treated California's coast this winter and am not a familiar enough with this coast to read the evidence.
Sunday, April 08, 2007
I spent Friday afternoon with the Snohomish County Beach Watchers. They had to endure an hour and a half in a darkened classroom watching slides before we headed for the beach. A sunny Friday afternoon meant that we were competing for space with the regular beach crowd.
In the 1970's, this was going to be the site of an oil refinery, but that fell through and a park and a golf course emerged. In the 1980s, the threat of erosion to park improvements near the tip of the point led to construction of a low steel sheetpile bulkhead with a concrete cap, which the waves have been throwing logs over the top of ever since. The simpler solution would have been to move the road and some picnic tables farther back, but our culture sees that as retreating - something we seem unwilling to accept as an acceptable solution! But two years of maintenance on a storm-damaged road has turned things around - the road will be relocated and maybe the bulkhead will be pulled out.
Although the back-barrier wetland - probably a salt marsh and tidal lagoon - has long been buried under fill and houses and parking lots, the remnants of the ebb-tidal delta where the original tidal channel emerged is still visible on the beach as a pronouced bulge a couple hundred yards north of the pier.
It's great to see the original Beach Watchers model (developed on Whidbey) being extended into other areas. This morning's Seattle Times has a nice piece about Beach Watchers.
Flying into Sea Tac last Monday from Sacramento, I got these shots of West Seattle through a smudged window. I'm often asked whether Alki Beach - visible on the northern shore of the point - is a nourished beach. Based on it's setting, and supported by some historical pictures, I think not. Alki is swash-aligned - it is oriented perfectly into the maximum northerly fetch and the geometry of Duwamish Head on the east and Alki Point on the west keep the sand from escaping. This is a recipe for a stable beach in Puget Sound.
Alki's story is a bit more complicated, however, since this whole section of West Seattle was lifted 20' out of the water about 1100 years ago when the Seattle Fault last shrugged. We believe that Alki was previously a double tombolo, with spits tying the little knoll near the tip of the point to the mainland. There may have been a salt marsh behind it. The evidence for this scenario is better on Restoration Point on Bainbridge - same geography, but not as densely developed. The earthquake lifted the entire landform out of the intertidal, resulting in a low point suurrounded by an eroding bluff ten? feet or so in elevation. This may have contributed to the isolation and stability of Alki Beach.
Third Beach, between Siwash Rock and Ferguson Point, is a pocket beach, contained by the orientation of the otherwise rocky coast to the westerly waves. The stability of the beach is aided with some bedrock ribs that extend like groins across the beach, and that have been amended with riprap. As with some other Vancouver beaches, I suspect that the beach has been enhanced with extra sand, but I don't know this for sure.
The December 14-15th wind storm, with help from a rainy winter, left a big dent on Stanley Park. The blowdown between Prospect Point and Third Beach was impressive. The road feels like a trench chainsawed through a wood pile ... but the views from the road toward North Vancouver are much improved! I watched a pair of bald eagles perched near their nest in one of the large trees along the shore that had not been snapped off 50' above the ground. Fallen trees and steep slopes have covered portions of the Seawall trail, which had already been severely damaged by the waves - reports and pictures of large sections of pavement being tossed around. The trail between Lion's Gate Bridge and Siwash Rock is closed and rexpected to remain so through the coming year. Another chunk of soil and trees came down on it in the heavy rain right before last week's conference.
I've heard some folks calling this a tragedy. If a bunch of kids with chain saws had done this, it would have been a tragedy. This was just a big storm doing what big storms are supposed to do - we can hope that no one gets hurt, but what makes Stanley Park special is that this kind of thing CAN still happen.