Saturday, April 14, 2018

Dungeness Spit Notes

I had a brief venture to the Dungeness River delta. Standing on the saltwater mash flats of the delta I had a view across the marsh and the water of Dungeness Bay.

The Dungeness Lighthouse was a speck on the horizon and only a bit more visible with the telephoto view.

Dungeness Bay looking towards the tip of the spit

Lighthouse viewed via telephoto view

The Dungeness Spit is a remarkable thin stretch of sand and gravel beach extending out into the Strait of Juan de Fuca over 6 miles from the main coast.

A big chunk of sediment comes from the high eroding bluffs to the southwest of the spite. These bluffs are exposed to fairly large waves coming into the open water of the Strait of Juan de Fuca. Ian Miller has put together a scheme for getting a better understanding of this remarkable spit (surveying-dungeness-spit). And it is remarkable - its the longest spit in the United States. Schwatz, Fabbri and Wallace (1987) provide a map of the sediment (drift) movement on this complex spit.

Drift map (Schwartz, Fabbri and Wallace, 1987)

The spit is complicated by the presence of another source of sediment from the southeast from sediment inputs from the Dungeness River as well as periodic waves generated by south winds blowing onto the backside of the spit.

Light House on distal lobe of the spit

Beyond the lighthouse, the spit is a no-entry wild life preserve as critical habitat for many bird species.

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