Extending instrumental sea-level records using coral microatolls, an example from Southeast Asia

• Main Authors: Majewski, Jędrzej M., Meltzner, Aron J., Switzer, Adam D., Shaw, Timothy Adam, Li, Tanghua, Bradley, Sarah, Walker, Jennifer S., Kopp, Robert E., Samanta, Dhrubajyoti, Natawidjaja, Danny H., Suwargadi, Bambang W., Horton, Benjamin Peter
• Other Authors: Asian School of the Environment
• Format: Article
• Language: English
• Published: 2022
• Subjects: Science::Geology; Sea Level; Microatolls; Extending Instrumental Sea-Level Records; Singapore
• Online Access: https://hdl.handle.net/10356/157145
• Institution: Nanyang Technological University

The small number of reliable long-term (i.e., >50 yrs) tide gauges in tropical locations is a major source of uncertainty in modern sea-level change. Coral microatolls record relative sea-level (RSL) change over their lifetimes and have the potential to extend the instrumental record. Here, we examined a 20th and 21st century RSL record from two living coral microatolls from Mapur Island, Indonesia, which produced 16 sea-level index points. We validated and combined the living coral microatoll data with tide gauge data to show RSL at Mapur Island was 0.0 ± 1.6 mm/yr (2σ) from 1915 to 1990 and 1.0 ± 2.1 mm/yr (2σ) from 1990 to 2019. Through the addition of microatoll RSL data we extended the record of modern sea-level change by over 50 years and reduced its uncertainty by ∼50%.