Scientists set sail to investigate high-resolution sea level, climate and coral reef records

A two-month expedition, running from 31 August 2023 to 31 October 2023 and managed by a team from BGS, has set sail from Hawai’i. The aim of the expedition is to better understand sea level and climate sea change by recovering and researching ancient fossilised coral reefs.

There is a series of twelve fossil coral reefs off the coast of Hawai’i that may reveal the history of sea level change in the region and beyond. The International Ocean Discovery Program (IODP) Expedition 389: Hawai’ian drowned reefs will sample these fossil coral reefs, giving scientists the first opportunity to investigate such high-resolution sea level, climate and reef response records from the past half a million years.

The international team will sample the ancient reefs at water depths up to 1155 m to study how sea level and climate have changed, how coral reefs respond to these changes, and the links between global sea-level changes and global climate change. The high-resolution records will also provide a framework for evaluating the effects of climate change originating from human activity.

A total of 29 scientists from across the world will participate in the expedition, with 10 scientists onboard the MMA Valour, which set sail from Honolulu on 31 August 2023.

Previous mission-specific platform expeditions around Tahiti (IODP 310: Tahiti sea level) and the Great Barrier Reef (IODP 325: Great Barrier Reef environmental changes) currently provide us with a record of past conditions over the past 30 000 years, but the Hawai’i expedition will greatly extend this over the past 500 000 years.

Due to the rapid subsidence of the island, Hawai’i is a perfect location for us to conduct this research, because changes in sea level and global climate are preserved in a greatly expanded and near-continuous fossil coral record covering the last half a million years.

It should also help us to reconstruct sea-level change at a much higher resolution than previously possible, as well as investigating the volcanic evolution of Hawai’i itself.

Dr Hannah Grant, BGS Marine Geoscientist and expedition project manager

Hannah is joined on board by two other BGS staff members, Graham Tulloch (operations manager) and Mary Mowat (data manager). Initial analysis of the recovered coral cores will begin on the ship and continue at the onshore science party, which will take place in February 2024 in Bremen, Germany.

Expedition organisation

The expedition is organised by the ECORD Science Operator (ESO) under instruction from the European Consortium for Ocean Research Drilling (ECORD) as part of IODP. IODP is an international marine research collaboration that explores Earth’s history and dynamics using oceangoing research platforms to recover data recorded in sea-floor sediments and rocks, and to monitor subsea-floor environments.

More information

• IODP Expedition 389: Hawaiian Drowned Reefs
• Expedition blog