Scientists say sea level change has formed Australia’s K’Gari Sand Island, Great Barrier Reef – Watts Up With That?

news7g11/16/2022

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Scientists say sea level change has formed Australia's K'Gari Sand Island, Great Barrier Reef - Watts Up With That?

The formation of the K’gari, also known as Fraser Island, and the Great Barrier Reef may be related to large climate feedback changes during the mid-Pleistocene transition.

A peer-reviewed publication

UTAH STATE UNIVERSITY

Scientists test Eolian Sands on K'Gari (Fraser Island) — IMAGE: RESEARCHERS FROM UTAH STATE UNIVERSITY AND QUEENSLAND UNIVERSITY TEST SAND FROM K’GARI EAST AUSTRALIA (FRASER ISLAND). THEIR WORK TOGET A NEW LIGHT ON THE FORMATION OF HUGE SANDS ISLAND, AS LIGHT AS THE BIG Fence. see more
CREDIT: STATE UNIVERSITY UTAH

LOGAN, UTAH, USA – How the world’s largest sand island K’gari, the indigenous name of Fraser Island in eastern Australia, along with the Great Barrier Reef, the world’s largest coral reef, came to be formed? Little is known about the formation of these UNESCO World Heritage sites, which were influenced by a long, stable tectonic history during the Quaternary period starting in 2, 6 million years ago.

But the new findings by geologist Tammy Rittenour of Wyoming State University and an international team of colleagues point to a modern-day concern that may have initiated the formation of the iconic landforms around the world. 800,000 years ago: sea level rise.

Rittenour and researchers from the University of Queensland, Australian National University, Flinders University, University of Western Australia, University of Canterbury, Clarkson University and Stockholm University report these findings in the November 14 issue. magazine’s 2022 natural geosciences. The team’s research was supported by an Australian Research Council grant.

“Our study provides evidence that the formation of the K’gari and the Great Barrier Reef is associated with changes in the magnitude of sea level rise and fall due to large climate feedback changes in Middle Pleistocene Transition,” said Rittenour, professor in USU’s Department of Geosciences and Ecology Center.

Using sediment samples from hand cores and bluff beaches, Rittenour, director of the USU Luminescence Laboratory, used optically stimulated luminescence dating to limit the formation time of the deposits. The island’s vast, sprawling sand dunes, as well as dunes from the adjacent Cooloola Sand Block. .

“We found that sand islands and dunes first formed 1.2-0.7 million years ago, during a period of climate restructuring, when increased global ice volume caused fluctuations Sea level redistributes sediment formerly stored on the continental shelf,” said Rittenour. speak. “The K’gari formation prevented the transport of sand northward along the coast, into areas where the Great Barrier Reef is present.”

The huge sand island’s protruding orientation has created the conditions for the clear waters necessary for coral growth, allowing the growth of the Great Barrier Reef.

“These important findings are changing the way we look at coastal sedimentary systems,” says Rittenour. “The overall change in coastal conditions during the mid Pleistocene is probably not unique to the east coast of Australia and should be studied in other passive marginal coasts around the world.”

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