Monday, March 29, 2010
It's remarkable that in 350+ posts over four years, I have none from Oregon! Unfortunately, this weekend's brief excursion did not lend itself to much rigorous beach exploration, but I decided to throw in a few coastal shots just to show we were there for a few hours on Sunday morning.
The photos capture the basic theme of Oregon's coast - broad sandy beaches and high rocky headlands. It also suggests that despite Oregon's generally enlightened and public-minded view of its beaches, the state has still left room for some mistakes and poor judgment.
Besides the Columbia River bridge in Astoria, the shots include the beach at Seaside, Tillamook Head, Haystack Rock at Cannon Beach, and Rockaway Beach.
Sunday, March 28, 2010
The north side of the entrance to Willapa Bay has been moving north for decades, gaining a reputation as the fastest eroding shoreline on the west coast. It's been disassembling the small beach North Cove neighborhood as it goes, leaving a trail of debris and pipes in it's wake.
But the land on which this neighborhood was built isn't exactly established ground. Beach logs, buried earlier by the advancing dunes, occasionally appear eroding from the bank. In 1921, when the Canadian Exporter ran aground, this must have been beach, but the ship's remains were subsequently buried by the dunes. Only to be re-exposed by the waves this year.
Another house went over the edge very recently and was still spilling it's belongings out onto the beach. Debris from houses lost earlier, garbage and tires from backyard piles, and asphalt from the streets litters the beach. The asphalt chunks were piled up and imbricated against the bank like shingle on British beaches.
The beach stretches over 10 miles from the south jetty of Grays Harbor in Westport down to North Cove on the north side of Willapa Bay. Most of it is a long stretch of broad flat beaches and today much of was lined with an army of folks trying to capture razor clams with stubby sections of white PVC pipe (official razor clam openings are rare, and we sort of stumbled on this one).
New wind turbines are going up on the hills to the east - quite an impressive complement to the clearcuts that have always marked the view.
Friday, March 19, 2010
Just a few miles and twenty minutes south of Birch Bay and what a difference. Wind and waves and a very different beach.
Gulf Road is the only place you can really get down to the shoreline in the vicinity of Cherry Point - unless you're an oil tanker or an aluminum ingot. Unlike the rest of Puget Sound, where high-end residential development is creeping along the shoreline like mold, this stretch was set aside decades ago for industrial uses and is marked by three large piers, two attached to refineries and one attached to an aluminum plant running on our famously inexpensive electricity. Ironically, the industrial designation may be what saves these beaches from being nickeled and dimed over the next few decades, although a little more public access would sure be nice.
This section of beach is actually a barrier, with wetlands behind and a small stream mouth at the north end.
Just like last year, a workshop in Blaine provided me a chance to swing home via Birch Bay (March, 2009). And just like last year, I'm going to keep my comments short, despite the amount that could be written about this fascinating part of Puget Sound (Georgia Strait, more precisely, or the Salish Sea).
This afternoon's theme is gravel swash bars. They happen to be located on a very long stream mouth spit on an elegant log spiral beach and one of the pictures is on a gravel beach built by Wolf Bauer almost three decades ago.
Saturday, March 06, 2010
Scatchet Head is the middle of the three big south facing headlands on the southern portion of Whidbey Island (Possession Point is to the east, Double Bluff to the west). The eastern portion of Scatchet Head is a row of homes built over the beach on some of the awfullest riprap on the Sound. The view is great. The storms are exciting (waves from the south; landslides from above). The location is unwise.
The western portion of the headland, from the homes westward toward Maple Point, consists of high forested bluffs - and seems to suffer from less erosion that one might expect - certainly less than at Possession or Double Bluff or the bluffs just around the corner to the northwest. Maybe this is due to more resistant geology or more dissipative bathymetry - or maybe it's something else.
Here's my idea. This straight stretch of bluffs is swash-aligned - the beach faces directly into the dominant fetch. This minimizes longshore transport and results in a more protective beach - sort of like a broad pocket beach. Erosion is ultimately about sediment loss and the only way for gravel to escape this beach is around Maple Point at the west end - and it may do this slowly.
Maple Point (I think I've seen it labeled Indian Point on some maps) is a small barrier - a recurved spit or cuspate foreland - located at the western corner of Scatchet Head (title of blog post links to the map view).
There is a complex series of intertidal berms and swales west of the point - maybe evidence of the spit's prehistory. There was no obvious depression or wetland behind the berm, but there were small dunes, which are unusual on these features - either due to insufficient sand and wind, or because they are so quickly destroyed by human activity. The clam shell on the storm berms on the north side was largely intact - a good indicator of the lack of human trampling.
What an amazing location! It is a wide place in the beach, isolated by high bluffs and remoteness, yet it feels like it's right in the middle of the Sound. The view includes the Cascades, Mount Rainer the Seattle skyline, the Olympics, Double Bluff, and of course the high bluffs north toward Maxwelton.
This walk, south from Maxwelton towards Scatchet Head, has been on my "beaches to explore on a beautiful Saturday afternoon" list for more than 15 years. But until today, I had only seen it from aerial photos or distantly from a boat or from the west side the Sound.
This is an amazing stretch of high, active bluffs, and probably not coincidentally, a wonderful expanse of broad sand flats. Once you round the bend from Maxwelton, the shoreline is largely free of human influence, other than the absence of the forest along much of the top edge of the bluff. Imagine what these cliffs would look like with old growth firs and hemlocks marching over the edge like lemmings!
We keep coming back to Mackie Park here in Maxwelton. Today, it is partly to check on the progress of the new spit and partly as a trail head for our long hike down to Scatchet Head.
I've reported on Maxwelton before (April 2009, March 2007), where the accretion of a sandy spit, and its progressive growth downdrift (to the north), has led to significant changes at the park. The spit has now made the ramp pretty dysfunctional (as a boat ramp, but the kids were loving playing the stream).
Possession Point marks the southernmost tip of Whidbey Island and is built of a tall stack of sediments that record a series of late Pleistocene glaciations. The 350' bluff has a propensity to collapse onto the beach in big chunks, but they don't stay long. Southerly waves rapidly move the sediment away, either east or west, depending on the storm and the orientation of the particular stretch of beach. On Puget Sound, we call beaches where the net direction of longshore transport is equivocal divergent zones. Once the sediment moves around the corner, it can pretty much only move north (sure, occasional northerlies might reverse this, but the odds are against it in the long run).
Possession Point feeds two drift cells. Sediment that moves east gets transported up the eastern side of the island, past Possession, Glendale, Columbia Beach, under the Clinton ferry dock, and on up to Sandy Point. The abundance of sediment and the orientation of the coast give rise to a series of extended spits that run along the base of the bluffs - beautiful wetlands now turned into long lines of houses.
Sand and gravel transported westward from Possession Point ends up in a spit on the east side of Cultus Bay now known as Sandy Hook - although its journey has been complicated by groins and parking lots built out across the beach.
The foreshore of the point is mainly coarse gravel - but like so many places on the Sound, if you remove the top layer of pebbles, what lies underneath is often sand and broken shell.