Chile Earthquake - Tsunami Reconnaissance Day 4
Posted on March 27 2010
Saturday March 27
Drove from Santiago to Concepción today – a distance of about 300 miles and a latitude change equivalent to going from the Salton Sea to Santa Cruz. It was my first chance to see the Chilean country side. The first part of the drive reminded me a lot of the Beaumont – Banning area and Concepción area seems very like the San Mateo coast. Chile turns your head around both in terms of directions and in seasons. It is a very linear country – the populated corridor bounded by the Andes and the coastal range. Sebastian says that people give directions according to North, South, Up, and Down. It’s just past the autumn equinox, days are getting short and one of the consequences of the earthquake is that the switch from Daylight Savings time to Standard time was postponed a few weeks to help the reconstruction effort.
As we drove south, earthquake damage became more prevalent. At first we only noticed some cracks along the road margins and soil slips on bridge overpass abutments. Then the road damage became more severe, some bridges completely down, and noticeable damage to adobe buildings. In Curicó, all of the adobe buildings appeared to be damaged, many tiles were off roofs, and piles of debris still sat on sidewalks. But it is still impressive how many structures are undamaged.
The reason for our detour into Curicó was in pursuit of an interview with the policeman who helped to save Iloca. Iloca is a small coastal village about 50 miles away from Curicó. We had read in the newspapers how this policeman had helped to save the people of Iloca by using his bullhorn to urge people to go to high ground. I’ve been interested in local tsunami heroes for some time and I really wanted to see if we could find this person and learn what had motivated him to take the actions he did. The problem – he was no longer stationed in Iloca. Much of the year only a few hundred people live there but during the summer, vacationers swell the ranks to over a thousand. Rather than maintain year-round police force large to handle the summer visitors, police from neighboring municipalities are rotated in to help coastal towns like Iloca in the peak periods. Our policeman was one of these extra summer officials. Fortunately, the newest member of our team is Francisco (Pancho) Luna. Pancho is a Childhood friend of Sebastian’s and an investigative journalist. It took him about ten phone calls and 45 minutes to track down his whereabouts and lead us into the heart of Curicó.
What ensued was an extraordinary interview. We spent over a half hour listening to his story and it will take us some time to complete a transcript and pull out all of the details, but there are several points that emerged right away. First, he had no particular training in tsunamis or earthquakes. He was from an inland community and had no cultural history or oral tradition about tsunamis. But he had been stationed in Valparaiso for 5 years during the time that tsunami hazard signs had been posted there. He had also participated in a number of drills and training exercises for other types of emergencies. Tsunami signs had also recently been posted in Iloca. In the early morning hours of February 27, he was able to see the ocean quite clearly because of the full moon. He didn’t immediately associate the strong ground shaking with a tsunami (the Valparaiso signs didn’t mention earthquakes), but he noticed the water becoming agitated and that reminded him of the signs so he organized the other police and they notified the town. He also had the instinct to keep people in the evacuation area until he got official notification that the danger period had passed. As a result of his actions, no one died and no one got hurt even though the town was destroyed.
Chile Earthquake - Tsunami Reconnaissance Day 2 & 3
Posted on March 26 2010
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.
Chile Earthquake - Tsunami Reconnaissance Day 1 Lori Dengler
Posted on March 24 2010
Wednesday March 24
Made it as far as Petaluma on the first leg of our trip to Chile. In addition to me, the group includes Troy Nicolini, the Warning Coordination Meteorologist of the Eureka NWS office – an engineer by background, and the coordinator of today’s Live code tsunami warning communications test, and Nick Graehl, geology grad student whose thesis project is studying the tsunami hazard in Yaquina Bay near Newport, Oregon.
The first lesson I’ve learned is not to schedule a tsunami test at the same time as a post-tsunami survey expedition. Troy has been up to his ears with all of the details of a three county live Emergency Alert System (EAS) test, siren activations, civil air patrol flyovers and we’ve both been busy with a massive educational campaign. The big danger with a Live Code test is that someone might be confused and think a real tsunami is on its way. For the test, I was stationed in Crescent City and had to be at a briefing at 8 AM. We won’t know how successful the test was until all of the information comes in over the next few days, but I was impressed with what I saw of Del Norte County’s full scale evacuation drill. Definitely very noisy at 10:15 when the sirens went off. The best moment for me was when all of the students and staff from St. Josephs school showed up. Tsunami aware children can be real heroes in tsunami events. Tillie Smith, aged 10, saved 100 people in Thailand in 2004 when she recognized the unusual wave activity as a possible tsunami and alerted people to get off the beach, and in the Chile earthquake, 12 year old Martina Maturana, rang the village bell alerting most of the inhabitants of Robinson Crusoe Island. This is a story we hope to learn more about.
After the test, Troy was contacted by a number of reporters. The furthest was a woman from Chile who had heard about our test on the internet. So now we have a Chilean media person to meet with in Santiago.
Samoa post tsunami field reconnaissance survey - Day 13
Posted on December 09 2009
The California State Lands Commission is one of the agencies that is helping to sponsoring our trip. The Commission’s interest in tsunamis is from its responsibilities for the safety of tankers off- and on-loading crude oil and processed petroleum products in the state and establishing safety regulations for marine oil terminals. They funded a project I worked on a few years ago looking at the tsunami hazard associated with marine oil terminal sites within San Francisco Bay. So today we visit the tank farm and fuel dock in Pago Pago harbor. The dock and tank farm are on government land and operated by BP. Tankers typically arrive twice a month to supply American Samoa with gasoline, diesel, fuel oil. Fortunately no tanker was in the area on September 29. The tank farm and fuel dock are located on the western side of the bay. Pago Pago harbor was one of the most heavily hit areas in American Samoa. Most of the water heights on the southern side of the island were in the 6 to 12 foot range. The harbor is shaped like a twisted triangle with a one mile wide mouth narrowing to less than a quarter mile at its head. This shape concentrated the flow and the International Survey Teams measured water heights of over 20 feet at the head of the bay. The Pago Pago tide gauge is located about 400 m west of the fuel dock and recorded peak water heights of about 7.2 feet above the mean tide level, with a maximum peak to trough oscillation of 12 feet. Observers at the fuel dock noted that the water came nearly to the dock platform but saw no water on the platform. The tank farm, on higher ground inland of the highway, also remained dry. We spoke with the safety officer and the managing engineer of the site who were concerned about what might have happened had a tanker been at the site. Their main worries were the currents, estimated between 12 and 16 knots, that might have been strong enough to pull the tanker away from the moorings if it had been at the dock. Two tuna boats double docked on the opposite side of the bay at the Startkist tuna cannery were reportedly broken loose of their moorings (we’re still following up on this story to get more details). The BP staff were concerned that the mooring bollards, the metal posts for connecting the mooring lines from the ships to the dock, would not have been strong enough to resist the flow. They thought that the mooring lines would have held but the two 50 ton and six 25 ton bollards might not have been sufficient to restrain the tanker. They are proposing replacing two of the smaller bollards with 50 tons. There were no problems at the tank farm. The facility is new – the oldest tank in the tank farm was built in 1989 and the newest in 2002 and all are built to resist seismic zone 4 shaking.
Next on the agenda was debris disposal. The first day we were in American Samoa, we heard an estimate of about 65,000 cubic yards of tsunami-generated debris. The debris is hand sorted on site into scrap metal and non-scrap, potentially hazardous materials like batteries and fuel drums removed, and the remainder sent to the Futiga landfill. Landfills are particularly problematic in tropical islands with limited space and high rainfall. The Futiga landfill is already nearing capacity – before the tsunami it was estimated to be filled in two years. It’s rather startling to see this large landfill tucked in the verdant valley adjacent to farms and homes. At the moment the tsunami debris are being piled on the edge of the landfill while the normal refuse is being incorporated into the main fill. There is a currently a debate going on as to how to process it – whether to do some compacting processing such as incineration before putting it into the landfill so in the interim, it’s all sitting on the sidelines.
Samoa post tsunami field reconnaissance survey - Day 12
Posted on November 08 2009
Switching island day. We have an exit meeting with the Government Official from the Ministry of Natural Resources, Environment and Meteorology who has been coordinating the overseas group. One of the stressful aspects of post-event reconnaissance is the need to synthesize our field observations to brief officials. We emphasize the preliminary nature of our remarks and the likelihood that some of our ideas may change and others added once we’ve had the chance to examine and thoroughly discuss our field data. Our conversation starts with the need for tsunami hazard maps that consider not only the September 29 event but other possible Pacific sources. Everything else builds upon a credible estimate of hazard – signing evacuation zones and routes, placement of evacuation/assembly sites, zoning and engineering design discussions, and educational messages. We also suggested some ideas for mapping the vulnerability of villages to tsunamis. A simple first step could be to time how long it takes to walk to a safe area and consider all areas that take ten minutes or longer problem zones that need to improve access to high ground or consider changes in land use. Our discussion touched on a number of other areas – education and outreach, building on the village structure to promote tsunami safety, design of coastal structures, formal and informal notification systems, and the need for better planning to coordinate warning response for far field events.
The skies are clear for our flight back to American Samoa and I get a good view of Amenave and Leone before we land. I check with Hawaiian on the status of my outbound flight and confirm the rumor is true. The Wednesday flight has been cancelled so I can’t leave until late Thursday which means changing the rest of my itinerary and missing another day of class. I’ve got a tight connection in Honolulu which makes me a little nervous. Get a good view of the scrap metal yard as we leave the airport. Tomorrow is a “debris day” and we hope to learn more about how the debris removal process is going.