NTU Researchers from Singapore discover an exceptional 7,400-year record of tsunamis in a coastal cave in Indonesia
- Press Release
Singapore, 19 July 2017
Scientists at the Earth Observatory of Singapore (EOS) and Asian School of the Environment (ASE) at Nanyang Technological University (NTU) have discovered an extraordinary 7,400-year record of past tsunamis in Aceh, Indonesia, the location of the 2004 Indian Ocean tsunami, one of the deadliest natural disasters of all time.
In a paper published in Nature Communications, Associate Professor Charles Martin Rubin, Professor Benjamin Horton, and Professor Kerry Sieh had identified sand layers laid down by tsunamis in the coastal cave. Through radiocarbon dating and an analysis of microscopic fossils known as foraminifera, the scientists were able to piece together a historical picture of the tsunamis battering the coastline of northern Sumatra.
The research revealed that the intervals between tsunamis range from 2,000 years to less than a century. While the likelihood of a destructive tsunami occurring in the Indian Ocean in the future is high, a correlation between the thickness of tsunami sand beds in the cave and tsunami recurrence intervals suggests that a long dormant period might follow the 2004 Indian Ocean tsunami.
“The study provides a remarkable snapshot of the past seven thousand years of tsunami behavior along the Sunda megathrust,” said Dr Rubin, Founding Chair of ASE. “The novel record of past tsunamis in the coastal cave is unlocking the geological mystery of when the next tsunami will occur in the region.”
Prof Horton added: “Historical records and instrumental records are too short to provide a full picture of the potential of large tsunamis, therefore we must find long-term records of the timing and recurrence of giant tsunamis to produce realistic vulnerability assessments for coastal communities.”
According to Prof Sieh, “This record of multiple tsunamis over the past eight thousand years contributes to answering a very important question: How often can we expect devastating tsunamis along the coasts of the Indian Ocean? It also shows that tsunamis along the coast of Aceh have been and may continue to be quite variable in their size and their frequency.”
Dr Rubin’s take-home message of this study is that “tsunamis are not evenly spaced through time. Our findings present a worrying picture of highly erratic tsunami recurrence. There can be long periods between tsunamis, but you can also get major tsunamis that are separated by just a few decades.”
This research is part of an on-going collaboration between the Earth Observatory of Singapore, Rutgers University-New Brunswick, Syiah Kuala University, University of Southern Mississippi, and University College Dublin. Support for this research was provided by EOS, International Centre for Aceh and Indian Ocean Studies, and the National Science Foundation, USA.
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The Earth Observatory of Singapore (EOS) is Singapore’s main hub for conducting research on geohazards, focusing on tectonics, volcanoes, and climate change in and around Southeast Asia. The Observatory is committed to acquiring knowledge of these natural hazards, passing this information on to affected communities by contributing to forecasts of such natural phenomena and helping them adapt to these environmental challenges.
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About Nanyang Technological University, Singapore (NTU)
A research-intensive public university, Nanyang Technological University, Singapore (NTU Singapore) has 33,500 undergraduate and postgraduate students in the Colleges of Engineering, Business, Science, Humanities, Arts, & Social Sciences, and its Interdisciplinary Graduate School. It has a new medical school, the Lee Kong Chian School of Medicine, set up jointly with Imperial College London.
NTU is also home to world-class autonomous institutes – the National Institute of Education, S Rajaratnam School of International Studies, Earth Observatory of Singapore, and Singapore Centre on Environmental Life Sciences Engineering – and various leading research centres such as the Nanyang Environment & Water Research Institute (NEWRI), Energy Research Institute @ NTU (ERI@N) and the Institute on Asian Consumer Insight (ACI).
Ranked 13th in the world, NTU has also been ranked the world’s top young university for the last two years running. The University’s main campus has been named one of the Top 15 Most Beautiful in the World. NTU also has a campus in Novena, Singapore’s medical district.
For more information, visit www.ntu.edu.sg