Sunday, October 13, 2013

Sombrio Beach

I drove down the dirt road, passing one car on its way out, sort of expecting to find the place empty, but I arrived at the parking lot to find dozens of cars, surf boards being unloaded, and wet suits being put on. It's a five minute walk down through the forest to the beach, and clearly improving weather and forecasts of an increasing swell had drawn out the Saturday afternoon crowd.  There were several clusters of surfers, a couple of kayakers, and a whole bunch of folks camping on the beach. 

Sombrio isn't really just one beach, but several, created by small promontories defined by offshore rocks, bedrock headlands, boulder fields, and even a stream mouth. Each of these segments was remarkably different and this whole place was a nice reminder that beaches aren't just simple functions of waves and sediment -- there are a lot of other geologic factors that go into them, too.

The main beach consisted of steep, coarse gravel, buried in storm-harvested kelp which had been washed up in huge tangles on the beach.

Google Maps: AERIAL VIEW

Another part of the beach was a sweeping berm of smaller well-sorted gravel, with a very steep slope and a high berm crest.  One thing that was very noticeable along this stretch was how much the elevation of the berm crest varied - reflecting differences in wave run-up and in the size and sorting of the beach sediment.

The southeasterly most beach lay beyond a headland that consisted of a small cliff of some very messy bedrock.  This is one of those outcrops that could keep geologists busy for hours, both trying to sort out the small details and trying to relate them to the bigger picture - the Leech River Fault crosses the coastline somewhere close by.  I'm not going to pursue the geological interpretation here - mainly because I had little idea what was going on!

No comments: