Professor to analyze tropical cyclone deposits in Thailand

Monday, May 6, 2013 - 20:45

DENTON (UNT), Texas — While the west coast of Thailand, on the Andaman Sea, can experience a tsunami, the nation’s east coast, on the Gulf of Thailand, is prone to tropical cyclones. The last major cyclone, Typhoon Gay, struck Thailand’s Chumphon Province as a Category 3 storm in November 1989, destroying several towns and leading to more than 800 fatalities.

Records of Thailand’s typhoons like Typhoon Gay only exist, however, for the past 50 to 60 years. A University of North Texas geography professor will join with a faculty member at Bangkok’s Chulalongkorn University to study evidence of ancient storms, which will help to determine the average intervals between major storms in Thailand.

 Harry Williams has received a $38,992 grant from the National Science Foundation’s Catalyzing New International Collaborations program to travel to Thailand this summer and begin the research with Montri Choowong, associate professor of geology at Chulalongkorn University, and UNT geography master’s student Eric Simon.

The three researchers will dig through layers of sediments in tidal marshes south of Bangkok on the Gulf of Thailand coast.

“A layer of sand in the muddy marsh would be out of place, and so would be an indication of a past tropical cyclone storm surge,” Williams said. “The main objective of the research is to identify and date storm surge sediment beds in the marshes to construct a long-term record of tropical cyclone strikes. Without long-term historical records of tropical cyclones, we can’t tell if a major storm occurs, on the average, every 100 years, 500 years or 1,000 years.”

He noted that many natural disasters have patterns of strikes.

“The smaller the intervals are between storms, the more governments need to be prepared with mitigation measures, such as planning evacuation routes and educating the citizens. If past disasters aren’t in most people’s recent memory, they may not be aware of possible storm threats and wouldn’t know how to prepare for them.”

Williams said the City of Seattle started to retrofit bridges to withstand earthquakes and tsunamis and plan evacuation routes in the 1990s after research determined that tsunamis impact the Pacific Northwest about every 300 years, on the average.

“The scientific evidence about typhoons and tsunamis will eventually work its way into public policy,” he said.

Since 2006, Williams has received more than $150,000 from the National Science Foundation’s Division of Ocean Sciences’ Marine Geology & Geophysics Program and the NSF’s Division of Earth Sciences’ Geomorphology and Land-use Dynamics Program to research storm surge deposits in the U.S., including those left behind by Hurricane Rita in 2005, Hurricane Ike in 2008, Hurricane Irene in 2011 and Hurricane Isaac in 2012. Williams also studied ancient hurricane deposits in the Chenier Plain of southwest Louisiana.

Williams and Simon will be in Thailand June 7-July 1. Williams previously visited Bangkok in August 2012 to meet with Choowong through a Charn Uswachoke International Development Fund Award from UNT’s Office of the Provost and Vice President for Academic Affairs.

Williams and Choowong plan to apply for additional funding to expand the research to other South Asian nations, including Vietnam, where Choowong has already started research. Williams said he would also like to study sediment deposits from ancient tsunamis on Thailand’s west coast.

“We’d like to determine methods for telling the difference between tsunami and tropical cyclone deposits, which will help to calculate recurrence intervals of both,” he said.    


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