A few weeks ago while surveying Kalaloch Beach I was struck by the loss of wood from the upper beach. Below, for example, is a 12 March 2014 photo of a pile of large wood pressed up against an old wooden bulkhead that protects the trail running down from the lodge to the beach. In this photo Casey Nattinger, who I was working with alongside some students from the North Olympic Peninsula Skills Center, stands atop a pile of large wood, which is itself perched on a pile of accreted sand:
and below is a photo of the same feature (from a slightly different perspective), taken on 16 January 2016. Use the wooden fence for reference. The wood, and much of the sand, has been removed:
The loss of the wood from this beach is either a cause or a consequence (or perhaps a bit of both), of erosion of the beach and bluff. Here is a profile collected just south of the wooden bulkhead:
which suggests meters of erosion of both the beach and bluff in the two years since the photo above from 2014 was shot. Its hard to say how big a deal this is...its likely that this beach erodes and recovers each year, and I've never surveyed this beach in January before. But the loss of the wood likely is important. Here is why: The video at the very top of this post was shot yesterday, 11 February 2016 at 3:30 pm, when the tide gauge in La Push was reading a still water level of about 2.9 m above MLLW. The water, driven by set-up due to large waves, was easily working away at the base of the bluff, which sits somewhere around 4.0m above MLLW. Presumably, in past years, some wood would have remained along the base of the bluff to helped to dissipate some of the energy prior to it striking the base of the bluff. So where did the wood go? Here is the water level time-series from La Push for the last month:
which suggests that yesterday's high tide (the last high tide in the time-series) really wasn't all that high compared to those that have happened over the last month (and indeed the whole winter). In other words, it is likely that the ocean has been spending a good bit of time on the upper beach. Note in the video at top how easily those large pieces of wood are moved by the combination of water level (floating the log) and wave energy. The mass of large wood that had been loaded against the upper beach here was floated away. Probably as a result, here is what the base of the bluff looks like as of 11 February 2016:
That sort of cupping at the base of bluff will precede failure, and as happens in all too many cases on the coast, there is investment (the cabins at the iconic Kalaloch lodge) in the way:
how long this site has isn't clear, but bluff erosion doesn't grow back...