Sunday, July 23, 2017

Strait of Juan de Fuca Mole

An article discussing Dunkirk's Mole reminded me of the mole on the shore of the Strait of Juan de Fuca.

Oblique view of mole on the Strait of Juan de Fuca (Ecology, 2006)

The mole along the Strait was used for loading clay onto barges from a clay mine up slope from the mole. The clay is from marine sediments of the Pyhst Formation. The clay was used as an additive to cement mixes.

The mine was a rather short lived operation. The Pyhst Formation is a rather notoriously unstable formation (clay!), and numerous very large landslides are associated with the marine clays. The mining slopes destabilized the slopes and activated a very large deep-seated landslide. The bare ground in the image above was part of the mine wall that failed, but the area of the slide is actually much larger and extends well into the uplands towards the top of the above photograph.

There has been some discussion of removing the unused mole as it is a protrusion that interferes with beach processes. I am not up on the status of that scheme. But the mole and the mine scheme are good examples of an approach to land use and shoreline use with long term consequences to the public in exchange for short term gain.    

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