Wednesday, July 31, 2013

A Not So Bad Whidbey Bluff

I took a short extra hike down a beach on the east side of Whidbey Island as the tide was way out.
 

A few notes on this very high and steep bluff. Although steep enough to be a bit off putting this bluff has some positive aspects geologically. First, the bluff material is all highly compacted glacial drift sediment or glacial advance outwash. It stands up so steep because it so hard and compacted and is almost concrete like. Note also the vegetation growing at the toe of the steep slope and on the upper beach. This indicates that waves and salt water very rarely reach the toe of this slope (at least of late). Hence, water erosion at this bluff has been very low. I suspect that the current main bluff erosion force on this slope in recent years has been freeze and thaw causing the outer layers to ravel off or stones to pop off the bluff face adding to the well nourished beach.

So, a not so bad bluff. There certainly are worse bluff sites on Whidbey Island.

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