- Fiji Experiences Record-Breaking Water Temperature After Half a Millennium
In the nearby Fiji Islands, located in the southwestern Pacific, the ocean's temperature has been unusually high over the past 600 years, as mentioned in a study published in the journal "Science Advanced." This revelation was backed up by Johannes Gutenberg University Mainz (JGU), who explained it as "additional evidence of the unprecedented warming of the western Pacific."
The researchers relied on the long-lived reef-building honeycomb coral (Diploastrea heliopora) to delve into the past climate records. These corals can live for hundreds of years, growing on average at a rate of 3-6 millimeters per year, according to JGU. The climate shifts of the past centuries can be traced within their skeletons.
The team scrutinized a nearly 2-meter-long core of such a coral. More specifically, they focused on the ratio of strontium to calcium within the core. This ratio helped determine the age of each layer using the uranium-thorium dating method, where the decay and conversion of uranium isotopes into thorium were considered.
By analyzing the coral data for the time period between 1370 and 1997, alongside 26 years of water temperature measurements, it was concluded that the year 2022 marked the warmest Pacific region temperature since 1370.
The southwestern Pacific plays a significant role in controlling global climate patterns including the well-known weather phenomenon El Niño-Southern Oscillation. This system is a coupled circulation pattern of ocean and atmosphere in the tropical Pacific, contributing to warming, changes in high and low pressure systems, winds, and precipitation during strong and moderate El Niño events.
Based on current climate simulations, the researchers anticipate that the 21st century will continue to see increased chances of either droughts or heavy rainfall, depending on the position in the Pacific. This could potentially bring widespread unfavorable consequences for the Pacific islands' inhabitants and their ecosystems.
The long-lived coral species used by researchers, Diploastrea heliopora, thrives on the reefs of the nearby Fiji Islands. The study of this coral's past climate records, specifically the ratio of strontium to calcium within a 2-meter-long coral core, revealed that the year 2022 had the highest ocean temperature in the southwestern Pacific since 1370.
