Day 160: January 21, 2008 Comodoro Rivadavia

  Comodoro Rivadavia, Argentina
Tuesday, January 22, 2008

Day 160: January 21, 2008 Comodoro Rivadavia

Today was a slow day. I got up late and wrote. I read the paper and learned a lot of new vocabulary, something I hadn't worked on in awhile. It was another hot day so I waited until after siesta time to go to the internet place but their connection was down so that was never done. Not wanting to return to the hotel, I decided to walk down to the gulf at the base of the street. The shoreline there appears to all be fill dumped in behind a seawall to make land for the high rises. It proved to be an interesting lesson in why seawalls don't work.

Rada Tilly Cliffs and the Golfo de San Jorge

Seawall Destruction

The tide was at peak high just a day short of the Full Moon spring tide, the highest tide of the month. The waves were breaking against the seawall. Much of it, on the south end, had already been destroyed by earlier wave action. There was almost no beach because all of the wave energy was focused at the seawall and eroded the sand away.

Constructive Wave Interference

Choppy Sea

When I first arrived I was surprised at how powerful and choppy the waves looked a little farther to the north, in front of the highrises. They were much more powerful those I had seen at low tide. After observing the wave action for a minute, I realized that the individual waves were a little less than a meter high. Most of the turbulence was being caused by the waves hitting the seawall parallel to the strike of the seawall. This caused the energy to be reflected off of the wall almost perfectly so that a return wave, almost as high as the incoming waves was heading back out to sea. When the waves collided, nearly perfect constructive interference caused the waves nearly double in size and break at the crest, throwing spray into the air. I used to teach this in Oceanography but had never observed nearly perfect constructive interference before.

After watching this show for about 15 minutes, I left the shoreline and walked back up into the neighborhood. I decided to walk around to try to scout out another restaurant. I probably walked about ten blocks but found nothing. I did, however, find the Supermercado La Anonima so I went in and bought a sandwich, beer, and some markers and pencils for our upcoming fieldwork. I took the goods back to the hotel and ate before watching a couple of movies and going to bed.