Unveiling Antarctica's Hidden Waves: A Race to Understand Underwater Tsunamis
An international team of researchers, led by the British Antarctic Survey (BAS), is embarking on a groundbreaking mission to unravel the mysteries of powerful underwater tsunamis triggered by glacier calving in Antarctica. These tsunamis, often hidden beneath the ocean's surface, have the potential to significantly impact marine life and climate regulation in the region.
When icebergs break off from glaciers and fall into the ocean, they create a phenomenon known as calving. This process can generate underwater tsunamis, which, despite their hidden nature, can reach heights of several meters. These tsunamis cause intense bursts of ocean mixing, where different layers of water are churned together, leading to a complex interplay of heat, oxygen, and nutrients across various depths.
Initially, scientists believed that wind, tides, and heat loss at the ocean surface were the primary drivers of this mixing. However, recent calculations have revealed a surprising revelation: underwater tsunamis play a significant role in polar oceans, rivaling the effects of wind-driven mixing in certain locations. In fact, they have a more substantial impact on redistributing heat in the ocean compared to tides.
The discovery of this phenomenon was serendipitous. Researchers on the BAS's previous research ship, the RRS James Clark Ross, accidentally collected ocean data before, during, and after a calving event during an expedition to Antarctica. Now, scientists are back in Antarctica, this time at the Rothera Research Station and aboard the UK's polar research ship, the RRS Sir David Attenborough, to delve deeper into the study of underwater tsunamis.
Leading the research is Professor Michael Meredith, an oceanographer at BAS. He aims to answer crucial questions: What triggers underwater tsunamis? How do they vary based on different types of calving? Do seasonal conditions influence their formation? And most importantly, how does the mixing caused by these tsunamis affect the polar climate and ecosystems?
To gather data, the team employs a range of advanced technologies, including satellites, remote cameras, drones, and underwater robots. They will venture to locations near glacier fronts that are too dangerous for researchers to access directly. By utilizing deep-learning algorithms to analyze satellite data and computer simulations to model tsunami generation and spread, the researchers will assess the impact of these mixing events on ocean temperature, nutrients, and marine productivity.
Dr. Alexander Brearley, an oceanographer at BAS who studies ocean mixing, is part of this cutting-edge team. He is currently at the Rothera Research Station, using an autonomous underwater vehicle to study the front of the nearby Sheldon Glacier. Dr. Brearley explains, "Our team is deploying a range of cutting-edge air, land-based, and ocean technology to understand individual glacier calving events with unprecedented resolution and detail, and the impact of the tsunamis they generate on the ocean."
The implications of underwater tsunamis and their resulting mixing effects could be far-reaching. Increased ocean mixing might draw more warm water from deeper ocean layers, accelerating the melting of the Antarctic Ice Sheet and raising sea levels worldwide. It can also alter nutrient distribution in the ocean, impacting the growth of phytoplankton, which forms the base of the marine food chain.
Professor Kate Hendry, a chemical oceanographer at BAS, emphasizes the significance of this research, stating, "Antarctica remains one of the most mysterious places on Earth, and we're constantly discovering previously unknown processes that shape our planet. What makes this research so important is that everything in Antarctica is interconnected - ice, ocean, and atmosphere - and these connections have far-reaching consequences for our world."
A critical question arises: How might the current warming climate influence the frequency and intensity of calving and tsunami events? By unraveling this phenomenon, scientists will refine ocean models, enabling more accurate predictions of future climate changes. The POLOMINTS project, led by BAS, is a collaborative effort involving several universities and research institutions, all working together to answer these crucial questions.
The POLOMINTS project is funded by the Natural Environment Research Council, and it aims to shed light on the complex relationship between underwater tsunamis, glacier calving, and the delicate balance of our planet's climate and ecosystems.
