Formation of K’gari, also known as Fraser Island, and Great Barrier Reef may be linked to major climate feedback changes during the Middle Pleistocene Transition
UTAH STATE UNIVERSITY
CREDIT: UTAH STATE UNIVERSITY
LOGAN, UTAH, USA – How did the world’s largest sand island K’gari, the indigenous name for eastern Australia’s Fraser Island, along with the Great Barrier Reef, the world’s largest coral reef, come to be? Little is known about the formation of these UNESCO World Heritage-listed sites, which have been influenced by a stable, long-term tectonic history over the Quaternary period that began 2.6 million years ago.
But new findings by Utah State University geoscientist Tammy Rittenour and an international team of colleagues point to a modern-day concern that could have initiated the iconic landforms’ beginnings some 800,000 years ago: sea-level rise.
Rittenour and researchers from the University of Queensland, Australian National University, Flinders University, the University of Western Australia, the University of Canterbury, Clarkson University and Stockholm University report the findings in the Nov. 14, 2022 issue of Nature Geoscience. The team’s research was supported by an Australian Research Council grant.
“Our research provides evidence that the formation of K’gari and the Great Barrier Reef are linked to a change in the magnitude of sea-level rise and fall due to major climate feedback changes during the Middle Pleistocene Transition,” says Rittenour, professor in USU’s Department of Geosciences and the Ecology Center.
Using sediment samples from hand cores and beach bluffs, Rittenour, director of the USU Luminescence Laboratory, used optically stimulated luminescence dating to constrain the time of formation of the island’s extensive, brightly hued sand dunes, as well as those from the adjacent Cooloola Sand Mass.
“We found that the sand island and dune fields first formed 1.2-0,7 million years ago, during a period of climate reconfiguration, when increasing global ice volume caused sea-level fluctuations that redistributed sediment previously stored on the continental shelf,” Rittenour says. “The formation of K’gari prevented the transport of sand northward along the coast, into the areas that now host the Great Barrier Reef.”
The outward-jutting orientation of the massive sand island created conditions for the crystal-clear water needed for coral growth, allowing the development of the Great Barrier Reef.
“These significant findings are changing the way we look at coastal sedimentary systems,” Rittenour says. “This wholesale change in coastal conditions during the middle Pleistocene is probably not unique to eastern Australia’s coast and should be investigated in other passive-margin coastlines around the world.”
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JOURNAL
Nature Geoscience
DOI
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Fraser Island and initiation of the Great Barrier Reef linked by Middle Pleistocene sea-level change
ARTICLE PUBLICATION DATE
14-Nov-2022
COI STATEMENT
The authors declare no competing interests.
Coral grows or dies, sand washes up on the beach and away again, cliffs fall into the sea or not, mangroves collect sediment or die, rivers make deltas….just as fast as sea level might rise or fall….humans building things below high tide plus anticipated storm surge plus a meter or so safety factor are the problem…..
That and overbuilding forcing subsidence on already low lying plains, islands, etc. Catastrophic anthropogenic climate change, indeed.
K’gari, Fraser Island also known asFraser IslandK’gari.It was named after Eliza Fraser, shipwreck survivor back in the 1800s.
Anyway, this bit –
Lacks context.
Fraser Is. is the north-most sand island in the chain of 5 large sand islands off the southern Queensland coast that include South Stradbroke Is, North Stradbroke Is, Moreton Is and Bribie Is.
(and about 6k years ago, the Spitfire Banks off the northern tip of Moreton Is would also have been above sea level, therefore comprising another large deposited sand mass)
My point is – Fraser is the last drop-off area for all the sand that is constantly transported northwards along the east coast of Oz, so the other large sand islands would have been forming before Fraser, so THEY ALL “prevented the transport of sand northward along the coast”.
And still do.
Can you weave into your explanation “point to a modern-day concern that could have initiated the iconic landforms’”?
I thought not.
No grant for you.
?
(ps – I’m not a grant- grifter, so no concern on that score).
(I believe he was supporting your point. Albeit, tongue-in-cheek.)
OK, I interpreted Robert’s “modern day concern” reference as pushing the “dangerous rising sea levels” dogma.
If I got this wrong RobertB, sorry, mea culpa.
I thought the Soup Nazi reference gave it away.
Don’t forget the Mary River dumps vast quantities of silt and sand against the West coast of Fraser Island every time it floods – so much so the island is virtually a river delta island.
You could probably walk across the seabed near the river to the island, at low tide.
I suspect the river is more responsible for Fraser Island than sea level change.
Tru dat Eric.
I once saw some army space cadets who tried to drive a Unimog across from the mainland to Fraser at low tide.
The water depth was ok, but the bottom was shifting sand, so all that was visible at high tide was wavelets breaking over the roof of the bogged, submerged Unimog.
Your taxes at work.
Ashley, , the really shallow parts of the Great Sandy Strait are quite a few miles south of the Mary River outlet. You have to be very aware of the tides to get through there safely in a keel boat 🙂
You mean…”Your taxes and ‘education’ system at work” don’t you?
I’m sure that someone will correct me, but…
During the glacial period the Great Barrier Reef did not exist in its present location. Where it is now was dry land. A precursor may have existed, but in a location hundreds of miles from where the reef lives now. As the sea level rose as the polar ice caps were melting the reef moved gradually to a location more hospitable to its survival.
Coral needs warm shallow water. As the water warmed it was able to move more toward the poles. As the Sea Level rose it was able to move more toward what is now the shore as its former habitat got too deep to allow light in.
Coral lives in warm water. Hence the Coral Sea. You find no living reefs in the Southern Ocean in the Southern Hemisphere nor North of the Keys in the Northern Hemisphere.
The reef may have moved back and forth as conditions changed, but existence in current form and place could not have happened more than 20000 years ago.
“You find no living reefs in the Southern Ocean in the Southern Hemisphere nor North of the Keys in the Northern Hemisphere”
Oh yes you do. I’ve found coral reefs growing west of Ireland in 700 metres. OK, Lophelia pertusa is not what people think of as a coral, but it is. The geochemists for whom I was working at the time thought that they fed on oil seeps. They also found about 20 tons of the stuff on the old Brent Spar from the North Sea. It wouldn’t surprise me in the least to find something similar in the Arctic Ocean.
Thank you for your input.
No problem. I agree with most of your post. Ain’t nature wonderful.
Yes “corals” cover a wide range of growths, not all hard or colorful.
Encountering some varieties up close, “sponges” would be what more readily springs to mind than “corals”.
Probably near the artic volcanic vents. Yes those do exist too (volcanic vents in the artic ocean).
Artic or Arctic?
Grammar Nazi needs to know!
Arctic! 🙂 How did I do that twice? *shakes head*
Bah, hah, ha!
So nothing to do with CO2 or human-caused climate change.
Natural climate change cant be mentioned as that will remind people that it didnt destroy the planet
Ignorant idiots!
Coral hosts billions of filter feeders. That is what makes for crystal clear water.
When the colonists first arrived in America’s Chesapeake Bay, the water was crystal clear from all of the oysters. Not because the Bay is separated from the oceans.
Nor do the authors explain how one sand island clears/cleans the water surrounding Australia, since the entire Great Barrier Reef surrounds most of Australia.
Also unstated is how a Glacial period ocean levels several hundred feet lower made such tall islands and reefs…
Er, you might want to re-think this bit of your comment.
The research was a different direction to your points
“Every year, around 500,000 cubic metres of sand is transported up the east coast of Australia from rivers such as the Hawkesbury and Hunter.
“It’s the reason why we have beautiful sandy beaches in New South Wales and Queensland,” Dr Ellerton said.As it is pushed north by south-easterly trade winds and waves, it builds around Stradbroke and Moreton islands and eventually reaches K’gari.
The island sits on a pivotal point on the south-eastern Queensland coast, close to the edge of the continental shelf.
As the sand hits the island’s northerly point, it slips off the edge of the shelf into deep water.”
hence the coastal drift sand doesnt move further up the coast and bury the coral reefs
https://www.abc.net.au/news/science/2022-11-15/kgari-fraser-island-age-links-to-great-barrier-reef-formation/101638104
This is a solid piece of research and uses some cool tools for age determination of sands. No doubt the sands were deposited during the Middle Pleistocene Transition, when periodicity of glaciation went from about 41,000 years to about 100,000 years, as they point out. A larger question, not addressed, is why the sands currently in place escaped redistribution by approximately eight cycles of glaciation and consequent sea-level rise and fall since that time? The later glaciation cycles produced much greater changes in sea level than the pre-MPT, 41K year cycles. My proposal for further research would be to identify the mechanism that raised the existing terrane above that affected by subsequent cycles of sea level rise and fall.
Nevada_Geo, I’m wondering what formation environment the sand accumulations display, water transport or aeolian transport? Why the article does not mention this is curious, as the formation mechanism would be displayed in the sedimentary texture. Any OZZIES out there that know the answer?
You need to look at the shelf. It sticks out that the position of Fraser Island and the reef starts where it is because of the shelf.
I have found (as in, its just a postulate) that the large gap in the reef might be due to Fraser Island causing run off to flow through an old river valley, dredging it of sedimentation.
Wind. Mt Tempest, on Moreton Is. to the south of Fraser Is. is ~ 1,000 feet high and supposed to be the highest sand hill in the world. Parts of Fraser are very high, too.
GBR has been around a looong time, but it dies and becomes islands with each glacial cycle and resurrects with each interglacial.
It should be renamed the Lazarus Reef (but every big reef could be named that too as they live and die with interglacial/glacial cycle)!!
Thats true .
And its not as if the Brisbane area and those sand islands dont have their own ‘minor’ coral reefs.
https://www.reefcheckaustralia.org/fraser_coast
And almost like clockwork now, whenever a Brisbane River flood event pushes a vast plume of sedimented fresh water into Moreton Bay, the alarmists cry that the sea grass beds and the coral reefs there are being destroyed.
Funny though that the sea grasses and the reefs are always found in rude good health within a year or so of the floods.
Brisbane is held together by coral dredged out of Moreton Bay.
G’Day Rick,
“Brisbane is held together by coral…”
Dredged up by the Cementco and the Estrella Del Mar back in the 1950’s.
The coral was turned into cement upstream at Goodna if I remember correctly.
The coral vessels were not the dredges. They were bottom dumping transporters that were loaded by the coal dredge off Mud Island. There was at least one before the Cementco that was replaced by the Darra.
The Estrella Del Mar was only ever used for river gravel on the Brisbane River as far as I can recall. It was sister ship to the Sorana Del Mar that my grandfather skippered through the late 50s and mid sixties.
Both the Estrella and Sorana were coastal capable vessels but I do not know their origin prior to operating as river gravel dredges.
I remember often seeing the Darra on the Brisbane River as we did our surf boat training sessions.
G’Day Rick,
Your memory is better than mine. It was about mid-night thirty this morning when I realized that I said Goodna, not Darra.
The vessels? I just kept out of their way. Oxley Sailing Club, a Thorpe Trainee, OT13, in 1957.
I wonder if the authors of the report considered that the currents along the east coast of Oz are generally north to south. And Fraser Island is south of the barrier reef. So how can an island that is downstream of the reef protect it?
Also, if you look at a map of Fraser island, you’ll find a region on the seaward coast where there are some natural igneous rock outcrops. As expected with a southerly drift current, the coast to the north is scalloped, indicating limited protection against an eroding current and to the south of the rocks, a long straight beach, indicating a leeward/protected deposition zone.
It looks like the university study group spent too much time lying in the sun rather than observing some basic details. And this article was published? Who reviewed it for accuracy and content?
Too woke for me, so this paper in the BS category, peer reviewed or not. Never heard of Kgari. I’ve been there, Fraser Island is a beautiful place to camp.
This graph shows that sea level was lower than now by 120 metres some 12,000 years ago.
This makes it unlikely that the present coastline was anywhere near its location today. If there was a Great Barrier Reef back then, it would have been East of where it is now. As sea levels rose, we might get to something like the modern configuration about 8,000 years ago.
https://en.wikipedia.org/wiki/Early_Holocene_sea_level_rise
We can but guess at geological events that affected Fraser Island since the date the authors report, some 1 million years ago. It is doubtful that events so long ago have significance in shaping the modern reef in the last 8,000 years.
The authors write of the currents moving sediments northward up the coast, from origins at river deltas south of Fraser Island. They are silent on sediments north of Fraser Island, where the same currents should have operated. What happens to the sediments from the Mary River, the Fitzroy River, the Burdekin River and so on? How could events starting at Fraser Island make the waters north of there so clear that coral growth was favoured, while these major rivers existed?
In the late 1980s, we tried to get access to explore for beach sand minerals at 2 locations well north of Fraser Island. These were Shoalwater Bay, south of Rockhampton and Lockhart River, getting near to Cape York. Our geologists reasoned that longshore sediment drift past these was enough to winnow the heavy minerals in occasional bays of the right shape, where they would concentrate. Our exploration was blocked by the United Nations world heritage scheme and later Shoalwater Bay became a military training area within. Therefore we were not able to test the hypothesis because of blatant political meddling. Our work, if allowed, would have posed no threat to the Reef. Geoff S