International geologists continue to examine inland coral boulders on Anegada in an effort to conclude whether the island was struck by a tsunami in pre-Columbian times.
Geosphere’s article makes the case that either a tsunami of nearby origin or an extraordinary storm washed brain coral boulders as far as one-third of a mile inland, according to Dr. Brian Atwater, one of the project’s researchers and a geologist at the United States Geological Survey.
Researchers will not be able to conclude which cause moved the coral until they compare data compiled from the boulders with different computer-generated tsunami outcomes — one of the next phases of the project, Dr. Atwater said.
In order to assist with that process, on the most recent trip they brought along scientists with the quantitative skills suited to examine boulder transport, the geologist explained.
Regardless of which scenario is more probable, the coral likely made its way inland sometime between the years 1200 and 1480, according to the Geosphere report.
Purpose
The nearly decade-long project is not simply about looking backwards, however.
“The idea is to use the extended view of earth history that the world provides to get a better sense of what nature can do along the Puerto Rico Trench,” Dr. Atwater said.
Such a perspective can lead to better preparedness for different outcomes, according to Sharleen DaBreo, director of the Department of Disaster Management.
“The more evidence we have of tsunamis in the region, the easier it will be to boost public awareness,” she said in a US Geological Survey press release. “As it stands, Caribbean tsunamis are so rare that some people may downplay tsunami hazards, even on low-lying shores that face the Puerto Rico Trench.”
Christa von Hillebrandt-Andrade — manager of the US National Oceanic and Atmospheric Administration’s National Weather Service Caribbean Tsunami Warning Programme — pointed to the tragic 2011 tsunami in Japan as evidence for the importance of deep historical research.
“When anticipating natural hazards, it’s important to know what happened many centuries into the past,” she said in the press release. “The 2011 tsunami was probably bigger than any other Japanese tsunami since the year 869.”
The findings also illustrate the importance of evacuation awareness that stretches beyond warning systems, according to Elizabeth Vanacore, a researcher at the Puerto Rico Seismic Network.
“A tsunami generated during an earthquake in the Puerto Rico Trench would reach our nearest shores in less than 30 minutes,” Dr. Vanacore said in the press release. “For many years we have advised people along the coast to respond immediately upon feeling a strong or long-lasting earthquake, by going to high ground or at least inland.”
{fcomment}