Saturday, June 02, 2007

Picnic Point

Enough of these white sand beaches, thousands of miles from Puget Sound. Time to bring this blog back home. This morning D&I headed north 15-20 miles and spent a couple hours tossing the frisbee on the beach and getting our shoes wet. Picnic Point is one of a few stream deltas between Seattle and Everett that extend seaward of the railroad grade. The stream mouth bounces around from season to season or year to year, but currently makes a sharp northerly bend (as it is supposed to do, given the southern exposure and the northerly drift) before fanning out down the beach.

The persistence of features like Picnic Point is intriguing. The supply of sediment to the beaches from bluff erosion has been largely, but not enitrely, eliminated by the railroad grade. The streams may provide some sediment. But I suspect that these points may attract what little coarse sediment remains in the system (I think this is a function of the oblique wave environment, which might shunt sediment to these places rather than away from them), keeping them from disappearing. This is an idea, one that might be tested, but by no means something I expect anyone else to actually believe!

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