Science & Technology

A new record of Singapore’s sea level history dating back 10,000 years

The state’s ability to predict sea level rise was strengthened by records dating back 10,000 years.

Climate scientists at Nanyang Technological University (NTU, Singapore) in Singapore have extended known sea level records in Singapore to nearly 10,000 years ago, providing a more robust dataset to help predict future sea level rise. ..

One of the main challenges in climate change research is to reconstruct its history over thousands of years. To better understand the potential causes and implications of future change, scientists need to learn from the past and understand it.

An international team led by NTU researchers extracted ancient sediments from a depth of up to 40 m underground at a site in Singapore’s Marina South and sampled samples using rigorous laboratory techniques (eg, micropores such as perforated insects). Data was obtained through fossil identification) and statistical analysis. Reproduce the sea surface history of Singapore.

For climate scientists, the more retroactive sea level records are, the clearer the predictions for the future. The transition at the beginning of the Holocene (10,000-7,000 years ago) represents the last major episode of natural global warming in Earth’s history, with melting ice sheets and warming sea levels. It rose 20 m. Singapore’s sea level has been stable for the past 3,000 years, but before the recent acceleration of the 20th century due to climate change.

Singapore Sea Surface History Research Team

The research team will examine core samples extracted from depths up to 40 meters underground at the Marina South site in Singapore.Credits: NTU Singapore

The lead author, Dr. Stephen Chua, who completed his research as part of his PhD at Singapore Earth Observatory (EOS) and NTU Singapore’s Asian Environmental School (ASE), said: 10,000 years ago, we got important new information from the early Holosen era. This is a period characterized by rapid sea level rise, but to this day it is poorly understood. “

“This more sophisticated sea level record also has broader implications. For example, it leads to stronger and more accurate on-site forecasts of sea level rise and provides a strategic guide for Singapore to adapt to climate change. “

Professor Maureen Raymo, Co-founding Dean of the Colombian Climate School Columbia UniversityAlthough not involved in the study, “This is the kind of important information we need to effectively plan adaptation measures as global warming continues to raise sea levels. Our past is ours. Affects the future of. “

Why is Marina South included in the survey?

To develop accurate ancient sea level records, it was necessary to extract sediments from “ideal” locations where sediments such as sea mud and mangrove peat were present.

To select the best mining site for accurate results, researchers examined the thousands of borehole logs available (records of holes drilled in the ground for infrastructure projects).

Singapore Sea Level History Core Sample

Core sample close-up. Samples are subjected to rigorous laboratory methods and statistical analysis to obtain data for reconstructing Singapore’s sea level history.Credits: NTU Singapore

Associate Professor Adam Switzer, who heads the Coastal Labs at ASE and EOS and was Dr. Chua’s supervisor, said: Stephen spent more than a year looking at old borehole information from various construction efforts over the last 30 years and found the right record. As a result, understanding of the geology of the region as a whole has improved dramatically. “

Findings useful for Singapore’s coastal defense program against rising sea levels

Studies published in peer-reviewed journals Holocene On June 4, 2021, we also found the first conclusive evidence that mangroves existed only in the Marina South region for about 300 years before succumbing to floods associated with rising sea levels at the time. Did.

At a depth of 20 m below sea level today, researchers have discovered that mangrove pollen is abundant. This indicates that the mangrove coastline existed in southern Singapore almost 10,000 years ago. NTU findings reveal that sea level rise during that period was as high as 10 to 15 mm per year, which may have led to the extinction of mangroves.

The findings provide Singapore with useful insights into current and future adaptation methods as the island nation seeks to go beyond engineering solutions and embrace natural methods to protect the country’s coastline.

Adam Switzer, Stephen Chua, Benjamin Houghton

The NTU Asian Environmental School team, which supports Singapore’s sea-level research, includes (LR) Associate Professor Adam Switzer, Researcher Dr. Stephen Chua, and Singapore Earth Observatory Professor Benjamin Horton.Credits: NTU Singapore

Despite its adaptability and effectiveness as a coastal defense, this study highlights the limits of mangroves in the event of rapid sea level rise. This supports a previous study co-authored by NTU that shows that mangroves cannot survive under high carbon emission scenarios when sea level rise exceeds 7 mm per year.

“Rising temperatures can have disastrous consequences for climate change, as rising temperatures melt ice sheets and warm seawater,” said Professor Benjamin Horton, co-author of the study and director of EOS. The rising scenario relies on understanding the reaction of sea levels to climate change. An accurate estimate of Singapore’s past sea level changes provides the background for such predictions. “

Professor Philip Gibbard, a Quaternary geologist at the Scott Polar Research Institute at the University of Cambridge, provided independent comments on the study, emphasizing the importance of records from remote areas such as Singapore.

“They provide a model of the process of sea level change that is not complicated by factors related to factors such as deglacial and effluent emissions. This important systematic contribution from Singapore and its regions is after-ice. It provides valuable records across the post-Holocene period and makes it possible to establish general patterns of sea level changes in the region, which will make more studies available in the future. As it gets more sophisticated, it can be refined. “

Reference: June 4, 2021, Holocene..
DOI: 10.1177/09596836211019096

A new record of Singapore’s sea level history dating back 10,000 years A new record of Singapore’s sea level history dating back 10,000 years

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