Thursday – Friday March 25 & 26
Petaluma to San Francisco to Dallas to Santiago. Flights on time but we almost weren’t. After all the years and miles of flying, I pulled a real beginner’s error – confusing the departure and boarding times. We were casually enjoying our dinner in an airport pub and we pulled out tickets to compare seats and discovered that boarding had begun 40 minutes ago and the gates were closing in 10. I think we were the last group on the plane. Because we made it, it’s a good story.

Sebastian Araya joined us in Dallas. Sebastian took my Natural Disasters Class in Fall 2000. He was a geography major at Humboldt and a terrific cartographer, a native of Chile and very interested in hazards. He was the top student in my class that term, and one of the top 2 or 3 who have ever taken that class from me. After the class, I continued to rely on Sebastian’s map-making skills for other projects and in the summer of 2001 when a magnitude 8.4 earthquake occurred in southern Peru, it took me about 10 seconds to decide I wanted Sebastian to accompany me on the International Tsunami Survey Team that Emile Okal of Northwestern was putting together. Sebastian was the hero of that trip, doing most of the surveys with survivors and managing to get our four-wheel drive out of a very precarious situation in the sand that another driver had gotten us into. After leaving Humboldt, Sebastian went on to get a Masters at the University of Colorado studying urban runoff problems in Santiago. After the Peru survey in 2001, he assisted a Japanese tsunami team in Chile in 2002, and went to Aysen in southern Chile in 2007 to study a landslide-generated tsunami.

No time to log on until Friday evening. We arrived in Santiago this morning after an 11 hour red eye. Earthquake signs all over the airport – missing ceiling tiles and cracks in the walls and ceilings and almost all the vendors (restaurants, rental cars, gift shops) have been moved to tents in the parking lot. But other than the airport, signs of a magnitude 8.8 earthquake are surprisingly rare in the city. A number of the pedestrian bridges were damaged and there is tape blocking certain areas but you’d never notice that anything is out of the ordinary.

We spent most of the day in a briefing organized by UNESCO and Laura Kong of the International Tsunami Information Center. It was very useful. We got reports from 4 teams who have recently finished their reconnaissance work – gave us a good foundation to build on. Three themes seem to be emerging:

1) Most deaths were caused by the tsunami, and the most vulnerable populations to the tsunami were the people camping on an island in the Constitución area followed by several other low-lying camp grounds. At least 50% of the tsunami victims appear to have been campers – we’ll try to pin this down. The earthquake struck on a very special day – a weekend celebration just before fall with local parties, camping trips and fireworks. If the same earthquake had occurred a few weeks later, or even during the week, the casualties numbers may have been cut in half. This really points out a problem for us on the North Coast – think Gold Bluffs Beach. We need to work much harder at educating the out of town camping populations.

2) There was a long time between successive surges, and in some locations, the largest surges may have been as much as four hours after the earthquake. There were a number of examples of people returning to the coast thinking it was over only to run to high ground as another surge rolled in. We’ve been preaching the long duration of a tsunami for many years, but now Troy and I are thinking of adding “Tsunamis are tricky – just when you think the danger may be over, more waves may come surging in”.

3) The peak water heights along the south central Chile coast are apparently very variable. In the 2004 Sumatra earthquake, one of the things that really struck me was the uniformity of the inundation zone. The 40 to 60 foot zone of stripped vegetation and exposed bedrock made it look like a ring around the bathtub that extended nearly 100 miles. In some places it was higher, but the general uniformity was very impressive. This tsunami seems to have been much patchier – high splash areas and then just around the corner much lower values. The tsunami scientists and modelers will have much to work with to explain the detail and complexity.

Tomorrow we head to the coast.