Monday, June 26, 2017

Fort Worden

It seems like all my recent posts have been from the Strait - the Miller Peninsula, the Elwha, and now, the northeastern corner of the Quimper Peninsula. But recent is relative. This Saturday excursion to Fort Worden was back on the 10th, but if you've been paying attention the last ten years, you know that sometimes my posts run a bit late. Always in order, but often delayed. If you've been following along, you also know that my photos and my narrative don't always align terribly well.

The beach walk was part of a grand loop around the north side of Fort Worden. We began with low tide on the north side of Point Wilson, where we could look at the curiously distinct and squared off boulder field and the wood debris sticking out of the beach along its western edge. Bulldozers, faults, or coastal retreat across a back-barrier lagoon that used to sit below a steep forested slope? And how does that relate to the big divot in the bluff that looks so much like a singular landslide, but which doesn't explain why the coastline itself jogs as well.


The beach along North Beach is great, with sand, gravel, big boulders, and occasionally glimpses of the underlying platform. But it's somewhat overshadowed - figuratively and literally - by the bluffs themselves. At the eastern end, it looks like Whidbey Formation, including a surprisingly continuous peat layer a few feet above beach level, overlain by Vashon stuff. But as you move west, the layer cake has been disturbed and late glacial Everson (so I'm told) appears - mainly gravels, but with some amazing ripups of the underlying glacial material. Something pretty exciting happened here during the waning stages of the last glaciation - it took a lot of water moving very fast to leave that kind of deposit (and it's much better exposed than my last visit). Is this evidence of Puget Sound (Lake Russell?) spilling out around the edge of the retreating ice? Or something else.

The walk back along the top edge of the bluff was a lesson in periodically relocated fence lines on the bluff (always to the south) and big artillery (the big guns are all gone, but the batteries and the views remain).

Credit for the day goes to Michael and Kitty and Leslie and all the other folks at:
The Jefferson Land Trust Geology Group

Thursday, June 01, 2017

Valley Creek

The mouth of Valley Creek was opened up a long time ago (10-15 years?), creating a small estuary out of once had been industrial fill, that I suppose once was a beach and a small estuary. In the last couple of years, the city completed the next phase of the park, which consists of two engineered beaches on the shoreline immediately east of the creek.


There have been a significant number of pocket beaches built on urban shorelines in the region, but this is one of very few that have been built as a pair. The idea has been proposed, but usually gets nixed due to costs and some basic geometric challenges. Constructed pocket beaches need to be oriented into the waves. And they need to be confined - either by existing promontories (usually old fill in urban areas) or groins.

This poses problems when a pair of beaches need to be oriented obliquely to the overall trend of the shoreline. The groin that separates them must often be a major feature, with a large difference in elevation from one side to the other (see aerial). This means a lot of rock is exposed (in this case, on the east end of the western beach). This in turn probably makes it harder to keep the higher beach from leaking through the rock structure - there was a little evidence that some of this might have happened here.

This site still seems pretty bare. It will be nice to see it with more vegetation, more landscape elements, and a few more amenities. it would be nice if we could incorporate more sand into these steep pebble beaches, but that's tough when you want stuff to stay put and your geometry requires the steep beach face provided by permeable, well-sorted gravel.

Here are links to some other constructed pocket beaches (some are very much the same, some are very much not):

Boulevard Park: 2014 (Bellingham)
Sunset Beach: 2016 (Vancouver)
Brackett's Landing: 2016 (Edmonds)
Sculpture Park: 2017 (Seattle)
Ross Bay: 2013 (Victoria)
Maumee State Park: 2010 (Ohio)
McKinley Beach: 2016 (Milwaukee)