Tuesday, November 16, 2010

Ten Waves per Minute

Last night we returned to our customary walk between the Washington Blvd. Pier and the Villa Marina jetty. I was curious to see how often the waves rolled in and so made sure I was wearing a watch, so that I could continue timing the periodicity of the waves.

Back in October, before I started this blog, I timed the waves that rolled in at the Villa Marina jetty. The rate at the time varied but the waves seemed to roll in at a rate of six to eight per minute. Yesterday, we began by walking the half-mile jag north from the Washington Blvd. pier to the little breakwater just north of Washington Boulevard. While we were walking, I tried to measure the periodicity of waves on that portion of the beach to see whether waves occurred with the same frequency as at the Villa Marina jetty.

Maybe it was the beautiful weather, maybe it was a heightened attention to my surroundings, but I simply could not seem to get accurate measurements yesterday. I would start timing when the second hand of my watch was straight up and would count 4-5 waves within the first 30-40 seconds, but then would lose my concentration. Also, last night, I noticed that not all waves are created equal. Sometimes, the waves are of uniform height and come in at regular intervals. Last night, though, it seemed like the waves' height varied considerably from one wave to the next. And, as often as not, a given wave would be followed by a smaller 'wavelet', a pale afterthought of a real wave. So should I count that as 1 wave or as 2 waves? I did not know and such considerations prevented me from ever completing a count through a full 60 seconds.

As though Nature were conspiring to divert me from my measurements, when we reached the small breakwater, I happened to notice a single dolphin swimming just beyond the point where the waves would start to swell before reaching full form. He (or she) seemed to be swimming a very narrow circuit between the breakwater and a point about 20 yards south. The dolphin would arch partway out of the water every so often but never so predictably that Alma could capture a picture of him. But I found that I would gladly ignore the second hand of my watch for a chance to see his back arch from the water.

Alma found herself taking pictures of some of the rock formations that form the breakwater. I told her that, if I were the Inspector of Sand Dunes, she was now the "Photographer of Rocks." Truth is, there are only so many things one can photograph down at the beach before the potential subject matter starts to run a bit dry. But Alma took some rockin' photos. Should we say that Alma rocks?

So, at any rate, I think in the Santa Monica Bay, under normal weather conditions, one expects to see about eight to ten waves per minute, or one every 5-6 seconds. I shall endeavor to measure the periodicity again when the weather has grown worse. The meteorologists are forecasting that temperatures will drop some 15-20 degrees by week's end and there may be rain this weekend. I would like to see if the frequency of waves increases when the weather worsens or whether the periodicity of waves remains constant no matter the weather.

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