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.



AERIAL VIEW

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.

AERIAL VIEW

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)

Wednesday, May 31, 2017

Dry Creek



The beach begins at the Elwha and ends at the tip of Ediz Hook -- at least in a simple, first-order conveyor belt of gravel, kind of way -- which is probably a little too simple. The central portion, between the eastern edge of the historic delta and the base of Ediz Hook, consists of 5 km of steep bluff. Dry Creek is in the middle.

AERIAL VIEW

From the Elwha to the ravine at aptly named Dry Creek, the bluffs are unarmored and the beach is wild. From Dry Creek to Port Angeles, things are a mess. The waterline was buried in the beach below the bluffs, but has subsequently been exposed by erosion and is now a 3km reach of riprap and sheet pile, below bluffs that continue to erode, albeit slower than they once did. Maybe it's fortunate that this beach is hard to access and most folks in town don't realize how bad it looks. Unfortunately, I don't have any pictures of this stretch to share in this post. I'll come back sometime.

The real highlight of this stretch, however, is the landfill immediately east of Dry Creek. The big wall goes back to 2006 or so and we can argue whether it's better or worse than the old refrigerators eroding out of the bank. But after the wall was built, folks discovered that maybe the eastern part of the landfill was at risk, too. The closest cell was a deep pit immediately behind the high eroding bluff. The good news is that they could have rocked the whole thing, but instead made the decision to move the vulnerable garbage out and move it landward. But in the process, they've left a remarkably bizarre landscape! And over time, this stretch will only get weirder.


There are a lot of photos of Dry Creek, the Elwha, and Ediz Hook in the blog. Searching within the blog on any of these terms should bring up earlier posts (although they sometimes bring up unexpected posts as well). Unfortunately, there are no pictures of the water line or of the landfill when the garbage was still slumping onto the beach.




East of the Elwha


As noted in the previous post, the rapid growth of the Elwha Delta following dam removal appears to have slowed. But during the past year or two, this eastern beach has grown rapidly as a result of a huge influx of sandy material. In places the beach has grown outward many tens of meters - with a steep cobble beach being replaced by a much broader sandier one.

AERIAL VIEW

Beach Lake refers to the lagoon, probably associated with an old channel of the river, that had been trapped behind the historic berm but that had been narrowed and breached by the rapidly retreating beach. Decades ago, a significant portion of this reach had been armored and this riprap was left in a broad arc on the beach face as the shoreline continued to erode.There was also at least one groin-like structure. All of these were recently removed by the Coastal Watersheds Institute and this, combined with the fresh sediment from the delta, has resulted in a much renewed beach.

The upland structures are slated to be removed. The plan is that this will become a public access - to a wonderful stretch of beach and to a highly regarded local surf break.

There is still one last stretch of rock and decayed timber bulkhead at the very eastern edge of the delta. As the beach has retreated, this rock has projected farther and farther onto the beach and looks like it may be exacerbating erosion at its eastern end. If it could be removed, the beach would be completely unarmored and unimpeded from the river mouth all the way to the Dry Creek (next post).



Elwha Delta


This is the first of two posts from the mouth of the Elwha. This one is built around photos taken near the tip - on both sides of the river mouth. The next post will be from a little farther east.

The river is currently flowing out into Freshwater Bay on the western side of the delta, although the linked imagery from Google Earth currently doesn't reflect this.

AERIAL VIEW

The broad crescent-shaped beach on the west side of the delta seems much simpler than the messy beach on the eastern side of the delta (next post). It has continued to accrete into Freshwater Bay and appears to be doing so in a fairly uniform fashion along its length. I guess this is how I might expect a swash-aligned beach to respond to additional sediment. But the beach on the east side is progressing much less cleanly - perhaps because of its drift alignment and the uneven transfer of sediment along its length. I say perhaps - I often say perhaps - to clarify that this is some speculation based on fairly limited observations. There are others watching this much more carefully and hopefully they will be able to put together a more rigorous story (and maybe a different story) in time.

The Elwha Dam was gone by mid-2012, the Glines Canyon Dam, farther upriver, was out in 2014. Fresh sediment reached the shore very quickly after the lower dam was removed and the new delta built out rapidly for at least four years. That process seems to have now slowed as the initial plugs of sediment flushed through and the reservoir bottoms have begun to stabilize.

The slowing (at least from what I can see) of delta growth provides an opportunity for coastal processes to take over. During the first few years, the beach east of the delta continued to retreat, despite the huge accretion at the river mouth. But in the last year or two, a huge amount of sand has moved east, perhaps as the front of the expanded delta has begun to erode.

Previous posts about the Elwha Delta


Wednesday, May 10, 2017

Travis Spit


It's a long, four mile walk on a coarse gravel and cobble beach from Thompson Spit to Travis Spit at the northwestern tip of the Miller Peninsula. The spit extends westward about a mile across the mouth of Sequim Bay - most of the way across, at least.  

AERIAL VIEW

While Travis itself is a fairly simple landform - a classic bay mouth spit - it's part of a complex of barrier beaches that make the story much more interesting. Together Travis and Gibson form paired spits, converging on the mouth of the bay. Gibson is also fairly large, extending south from Port Williams across Washington Harbor, and sheltering a large salt marsh. There's another smaller spit that extends north from the south shore of Washington Harbor. And Paradise Cove Spit is a north-directed spit that has formed just south of the base of Travis Spit on the eastern shore of Sequim Bay. Finally, if you look carefully, you'll see a small secondary spit on the southern side of the distal portion of Travis, with it's own narrow log-choked lagoon. You really need the aerial view and the map for this.




250 meters across the Sequim Bay channel is the site of the old Bugge Cannery (clams), which has been Battelle's Marine Science Laboratory for the last few decades. From the signs, I gather that Battelle may own much of high ground on Travis Spit. The central portion of Travis is narrow, but not so narrow as to show any obvious signs of overwash.


From the tip of Travis, it was a very long walk back to the State Park trail, a not so long walk up the trail to my bike, and then a refreshing ride back to my car. With a quick stop at the Discovery Bay store for chips, I made the 5:30 Kingston Ferry.

For those interested in visiting the Miller Peninsula or Travis Spit, a couple of thoughts. Miller Peninsula State Park is undeveloped, except for a new parking lot off of the Diamond Point Road and a network of trails largely maintained and signed by volunteers. Thompson Spit is best visited by hiking or biking in from the State Park parking lot. Travis would be best visited by parking at Panorama Vista County Park, which is reached off of the East Sequim Bay Road. 





Tuesday, May 09, 2017

Thompson Spit


The Miller Peninsula, on the north side of the Olympic Peninsula, lies between Discovery Bay on the east and Sequim Bay on the west. Diamond Point is the cuspate foreland that marks the northeast corner and the entrance to Discovery Bay. Travis Spit extends from the northwest corner across the mouth of Sequim Bay. In between is about 5 miles of gravel and cobble beach, backed by steep bluffs.

AERIAL VIEW

The one exception to this long stretch of bluffs is Thompson Spit, located near the eastern end. The spit is a looped barrier - basically a spit that extends out from the coast and then reconnects farther down the shore (in this case, west to east, which is consistent with what we expect of longshore transport here). They're rarely symmetric and this one is no exception. Their updrift ends are often tangent to the adjacent bluff - as if the beach reached a sharp bend in the coastline but couldn't turn fast enough. The downdrift ends tend to merge back to the coastline asymptotically. If there is a tidal inlet, it's usually near this downdrift end (that's not the case at here, which just suggests a more complex geologic or historic story that I don't know).

The berm on the western end is low and narrow and there was evidence of overwash. The lagoon was draining through a shallow inlet and the beach in front of the inlet was marked by several organic ledges (the upper looked more like sawdust - perhaps evidence of some human history?) - which is typical where a barrier beach has migrated landward, exposing old marsh and lagoon sediments. The central point of the spit is marked by a large mound that appears to be fill - was there an old cabin or small mill here once?

This may have been referred to as Deadman's Spit at one point - the dead man being a guy named Thompson in the 1860s. But that may be reading too much into a local history I found online (Diamond Point history).

I'd like to come back and explore more sometime - lots of unanswered questions. But only the western portion of the spit is in the State Park and I'm not sure how welcoming the owners of the eastern half are likely to be.

Looped barriers are common on Puget Sound - here are a few we've visited before:
Perego's Lagoon: December 2015
Cama Beach: April 2017 (and many previous)
Kayak Point: January 2009

Tuesday, April 25, 2017

Cama Beach

Last week I got a chance to visit Cama Beach to talk to this spring's Sound Water Stewards class. The weather cooperated for the beach walk - which it seems like it usually does, but this year I wasn't so sure!  I managed to grab a few photos, but not many. When I'm with a group, I'm too busy answering questions or looking for topical material to remember to take pictures.

AERIAL VIEW

The beach at the south end is very low, although not necessarily lower than in 2012 (Cama Beach: May 2009). However, a little farther north, near the old gate in the seawall, it was as low as I've ever seen it. The old wooden piles were completely exposed and there were large patches where the beach veneer was completely absent, with the underlying silt and clay showing through.

At the north end, we checked out the two big slide scars from previous years (see linked posts below). Despite this winter's record rainfall, it doesn't look there's been that much activity.

There was eelgrass hanging from the branches of the trees - a reminder of the interaction between the terrestrial and marine ecosystems. And there was a wonderfully delicate micro-berm of ground up clam shell marking last night's high tide.

Previous posts that mention Cama Beach.



Saturday, April 08, 2017

Hug Point



Hug Point is a small rocky headland that extends out across the beach a few miles south of Cannon Beach. The rocks include both Tertiary sediments and an intrusion of Columbia River basalt. 100 years ago, travel along the coast generally used the beach, but at Hug Point, a road was carved into the promontory (the old roadbed doesn't show in these photos).

AERIAL VIEW

Fall Creek arrives at the beach over an 8' waterfall. As streams often do on these kinds of beaches, it exposed the coarse cobble that underlies the upper part of the more ephemeral sandy beach.