From the UNIVERSITY OF SYDNEY
Did rapid sea-level rise drown fossil coral reefs around Hawaii?
Investigations to predict changes in sea levels and their impacts on coastal systems are a step closer, as a result of international collaboration between the University of Sydney and researchers from Japan, Spain, and the United States.
Scientists globally are investigating just how quickly sea-level rise can occur as a result of global warming and ice sheets melting.
Recent findings suggest that episodes of very rapid sea-level rise of about 20m in less than 500 years occurred in the last deglaciation, caused by periods of catastrophic ice-sheet collapse as the Earth warmed after the last ice age about 20,000 years ago.
Lead author, PhD candidate at the University of Sydney, Kelsey Sanborn, has shown this sea-level rise event was associated with “drowning” or death of coral reefs in Hawaii.
VIDEO: This is an animation showing the initial rapid flooding of the -150m reef terrace, shown by the rising blue sea level. The location of sample recovery is shown by the purple cube. CREDIT Bathymetry data from Monterey Bay Aquarium Research Institute, and animation by Kelsey Sanborn, University of Sydney.
CREDIT: BATHYMETRY DATA FROM MONTEREY BAY AQUARIUM RESEARCH INSTITUTE, AND ANIMATION BY KELSEY SANBORN, UNIVERSITY OF SYDNEY.
The results are published today in leading geosciences journal Quaternary Science Reviews.
The paper provides new evidence of a meltwater pulse (referred to as meltwater pulse 1-A), based on analysis of fossil coral reef samples from off the coast of Kawaihae, on the northwest of the Big Island of Hawaii.
Co-author Associate Professor Jody Webster, from the Geocoastal Research Group at the University of Sydney’s School of Geosciences, said although this pulse was greater than current modelling predictions of sea-level rise over the next few hundred years, it provides an example of the risks rapid environmental change poses to our marine ecosystems.
“If we saw a sea-level rise in the future of a similar rate as this past event, it would likely devastate coral reefs and coastal systems,” Associate Professor Webster said.
The fossil corals used in this study were collected by a team of technical rebreather scuba divers who dove down to 150 m below present sea level to access the fossil reef. At this depth, more than 130m deeper than where you could dive along their living shallow counterparts today, the divers recovered targeted shallow reef species that were alive over 14,700 years ago.
Lead author Ms Sanborn said this coral reef had been growing for thousands of years, during the initially gradual sea-level rise as the ice sheets of the last ice age began to melt.
“During the meltwater pulse, sea level rose more rapidly than the reef could grow, preventing the photosynthetic algae living within the corals from receiving enough sunlight. This caused the previously thriving fringing reef system to drown, and left it to be overgrown by deep-water algae and other marine life,” she said.
Although uncertainty remains regarding how quickly coastal areas could be inundated around the world, understanding how these events occurred in the past are key to understanding the risks we face in the future.
“The fact that this meltwater pulse was large enough to drown a large, active Hawaiian reef system implies that extreme climate change and associated sea-level rise occurred quite rapidly,” Ms Sanborn said.
This event is believed to have been brought about by catastrophic melting of the Greenland, and potentially also Antarctic, ice sheets.
“This may help us better predict the extent of future sea-level rise based on how vulnerable the Antarctic ice sheet is to collapse and melting,” Ms Sanborn said.
The research was a collaborative effort between the University of Sydney, the University of Tokyo, the University of Florida, the University of Granada, the Monterey Bay Aquarium Research Institute, the University of Hawaii, and the Association for Marine Exploration.
RESEARCH DETAILS
As part of the research, Ms Sanborn examined the evidence for reef drowning by identifying the coral reef species which grow within a specific depth range, and dating them using radiocarbon dating.
Taking into account the sinking of the island due to its volcanism, the relative-sea level history of Kawaihae was reconstructed.
The findings suggest that this reef was rapidly drowned by the combined effects of sinking of the island and global sea-level rise.
This is supported by other studies from around the world showing a rapid sea-level rise around 14,700 years ago.
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Funny thing, I never hear much about climate change in Hawaii. The climate seems very stable. I think that if warming were occurring, the Hawaiian Islands would be like the canary in the coal mine. Is the overall temperature warming there? It seems to me to be the “perfect” climate with little variability.
I think Hawaii’s temperature is controlled by sea surface temperature (SST). The global SST has changed very little (<<1°C). Therefore, Hawaii (and places like Florida and Iceland) will show no measurable change. I guess Iceland is controlled by the gulf stream. A shift in location of the gulf stream would have a huge effect on Iceland (and I think the UK). A shift in the gulf stream would not necessarily be associated with a change in global SST.
Iceland was quite heavily glaciated during the ice ages. It has extensive ice-caps even now.
True, but I am pointing out that as long as the gulf stream stays put, Iceland is unlikely to experience significant climate change (even if the globe warms). An interesting fact, due to the relatively warm SST around Iceland due to the gulf stream, they have a fairly constant temperature. Their summer to winter temperature variation is much lower than other locations at similar latitude.
Right so problem solved, it’s not global and obviously not catastrophic
Without wishing to nitpick, the Greenland ice sheet hardly melted at all – it is locked in place by a ring of protective mountains. One the other hand, the Laurentide ice sheet did melt – in its entirity.
The topographic bowl that protects the Greenland ice sheet.
Otherwise, the Greenland sheet would have melted during the Holocene Maximum.
http://www.csmonitor.com/var/ezflow_site/storage/images/media/content/2013/0830-greenland-canyon-topographic/16859445-1-eng-US/0830-Greenland-canyon-topographic_full_600.jpg
uuuuhhhhhggg animations and computer models “proof” the world is going to drown and it is all humans fault!!!!! run for Mars!!!!! Seems that comedian spouted a universal truth… “you can’t fix stupid” – can’t recall his name at the moment. Entirely too many supposedly intelligent people are stuck on stupid, can’t recall it being this bad when I was younger.
Cheers!
Joe
Ron White?
yes that’s him! Thank you! 🙂
In spite of tty’s relative forgiveness towards the alleged researchers for using the word “drown”; the reality is that corals do not “drown” per se. What happened to those Hawaii corals is definitely not described in clear scientific language.
The only relatively close meanings’ of “drown” is to “submerge”. Those corals were already “submerged”.
“Drown” as used by the alleged researcher PhD candidate at the University of Sydney, Kelsey Sanborn is solely meant to alarm, not inform.
Any “current modeling predictions of sea-level rise” claiming sea level increases of similar magnitude are not true models or predictions. Those models allegedly predicting such huge melt water pulses are pure speculation requiring absurd assumptions on the part of the modelers.
In other words, an extended Hawaiian vacation scuba and skin diving.
Multiple specious claims without evidence to support.
One wonders just what deep research this team performed regarding their claims?
Now there is a frightening claim totally without merit.
“Devastate”.
No!
From dear NOAA:
One, just one of coral’s prolificacy mechanisms is spawning immense amounts of free floating planulae, which spread anywhere ocean water flows.
Wherever a coral’s specific environment conditions are right, these planulae anchor, thrive and spawn.
A mechanism that works extremely well as corals have survived multiple glaciations and inter-glacials.
Bloody Holocene Period, they ought have put a tax on it.
Why did they say all this meltwater came from Greenland and Antarctica, when there was A MILE OF ICE over 1/3 of the NA continent?
They are trying to scare people into thinking that it could reasonable happen again in the near future (our lifetime or our kids lifetime). Obviously, whatever sea level rise there is will be slow (as Greenland and Antarctica are way too cold to catastrophically melt)
Surely the Holocene melting would have been in the form of a poleward migration of the permanent snow line? It would not have occurred as an all-over loss of ice across the entire cryosphere.
The current permanent snowlines around the coasts of Greenland and Antarctica more-or-less represent the extreme limit. Any ice above these lines will have been there for a very long time.
The Greenland ice cores and the Vostok ice cores provide a continuous record going back several hundred thousand years precisely because absolutely NO melting has taken place at those locations in that time?
For East Antarctica, yes. On Greenland no ice older than the penultimate glaciation has been found, but study of rocks and organic materials brought up from below the ice by drill cores do indicate that there has been no complete melting of the lowland part of the icecap for at least 1.8 million years. The highland ice cap in East Greenland is probably as old as the ice in East Antarctica.
Strangely enough there has been very little drilling in West Antarctica, and none to the bottom in areas where old ice might be found (perhaps because such old ice would essentially kill the “catastrophic sea-level rise” meme?). However surface ice older than the last interglaciation has been found in several places in West Antarctica and the ANDRILL-1B core in the Ross Sea strongly suggests that the WAIS ice sheet has not been much smaller than now for at least 1 million years.
And ice in Antarctica did decrease a bit at the end of the last glaciation. This was mostly caused by the sea-level rise when northern hemisphere ice melted. Ice in Antarctia is essentially limited by the deep sea all around the continent since glacier ice is not stable in water depths greater than about 500 meters, so when sea levels rose the ice-edge retreated. On the other hand ice inland in East Antarctica may actually be thicker now than during the glaciation due to more snow.
Why is anyone even responding to something so utterly pointless by this amazingly daft so called student? In denial of the known climate record pushing a line that even my dog wouldn’t swallow. Change happens, with or without humans. Get over it. And stop wasting Oz taxpayers money on bad science (BS) used as an excuse for a Hawaiian holiday. Now i’m doing it. Doh!
I think I should figure out some climate change study to do in Hawaii. Probably will take about 10 or 15 years to complete the study. Please send money.
Lots of studies of the volcanoes and the corals, garnts need to include the words climate change effect on, or the effect on climate change of. Get writing….how can they refuse, when inevitable climate change catastrophe is coming soon..’ish, maybe, one way or another.
Saw University of Sydney, eyes glazed, came straight down here to comments.
Sydney Uni does seem to have that reputation.
Wouldn’t you use the word drown to describe being starved of oxygen rather than being ‘starved’ of sunlight? It’s just a language quibble, but it seems the wrong word to use for what happened.
When you approach your research from a negative viewpoint, you miss out on the real story. Summary of article’s research: Rapid SLR, coral died. Duh!
Real exciting scientific question and conclusions I take from the exact same study: Rapid SLR coral survived! How?
Well as usual numerous WUWT responders ahead of me answered the ‘How’ thoroughly. The takeaway? Class Anthozoa, as a group are leaders among the toughest, most persistent creatures in the geologic record. They have existed for over half a billion years through hot and cold earth’s, through the aftermath of numerous bolides that have smashed into earth and killed almost everything else. There are numerous species and can be found from deep (3000m) to shallow, warm to cold water (off Washington coast, off Scotland) and countless species have gone extinct but they keep cranking out new species of this most successful format.
These tough bestids will outlast every other creature on the planet and already have attended the funerals of 95% of all the species of life that ever lived. Coral will be there representing the last life at the earth’s funeral.
You biology types that want to tell sad stories of imminent death and destruction. Steer clear of these gritty little blighters.
Gary Pearse September 28, 2017 at 2:49 pm
Sorry, they are just a flash in the pan compared to my heroes…the Stromatolites. THEY will be here in 1 biliion years, not sure about your lot!
I recall a show on National Geographic, which stated that during this period, global sea level rose around 65 feet during 100 yr periods — or, about 170 times faster than today.
At most, SLR at the present stage of the interglacial is but a few millimeters per year, nowhere close to the 4 cm/yr. seen in spurts during the last deglaciation. Any spooked owner of coastal property in Hawai’i eager to unload his holdings at a steep discount, please contact me immediately for an all-cash sale.
“The findings suggest that this reef was rapidly drowned by the combined effects of sinking of the island and global sea-level rise.”
If global sea level rise drown this reef in Hawaii, then similar phenomena would be found elsewhere in the world. Until then, there is no reason to attribute anything to global sea level rise.
Catastrophic climate change is likely the average event on Earth, not the benevolent stable climate event on Earth. Is it possible that catastrophe drives evolutionary adaptation and specie robustness?
Yes, and at all scale levels!
For example, in Hawaii, lava flows can create isolated islands of flora and fauna, which then evolve differences in species despite their close proximity.
A qualified yes. Though abrupt climatic change can also cause extinction, particularly after a long period of relative stability. However we do live in a glacial era of extreme climatic variability, so virtually all extant species (e. g. corals) are known to have survived repeated and extreme climatic changes. The exceptions are a few very young species (mostly plant species of hybrid origin) which have originated during the present interglacial.
Hell, all this destruction, without a single SUV or coal fired power house to blame.
No wonder the greenies of the day had a hard time blaming man..
Sp I’m confused, what did we do wrong 15,000 years ago to cause this sudden ice melt? Certainly humans caused that too right. I mean the CO2 levels must have tippled every year back then due to new tribes starting a cooking fires due to the the growth of the population
Exactly! I wonder if the author of this ‘study’ realized that, in drawing the conclusions he did, he proved the hypothesis that human COULD NOT be a principal cause of global warming. ie It warmed enough to ‘drown’ the coral (still trying to wrap my head around how something that lives entirely underwater can drown!) but man cannot be a cause of the sea level rise simply because he wasn’t around back then (20,000+ years ago). ipso facto
Reckless time traveling humans belonging to a greedy corporation. Obviously.
Oh, and they also carried guns and were white heterosexual males.
All these comments are responding (more or less rightly) to a news article about a new paper, which isn’t linked to in the post and is paywalled anyway.
It’s almost beyond belief that anyone with a bit of scientific training, even a Ph.D. candidate at the University of Sydney, could make statements as inane as those quoted in the post. More likely, she was prompted by a reporter to make responses to leading questions, which then had selected words, phrases or sentences taken out of context and threaded together with bits from the abstract to produce an article replete with hints of impending disaster.
If an honest reporter with education, intelligence, insight and integrity (that’s a theoretical construct that has never been observed in the wild, although a 20,000 year-old, frozen corpse recently excavated from melting permafrost is believed to have been an early member of the sub-species that subsequently went extinct due to climate change) had understood the substance and the significance of the observations reported in the paper and produced an article saying “New study shows that Hawaiian coral reefs survived rapid sea-level rise by recolonizing at higher levels”, would it have been published?
Silly (and rhetorical) question.
Having been interviewed by a journalist and seen my (non-controversial, routine, boring) words taken out of context in an attempt to make a story that bore only the remotest resemblance to what I actually said, I really can’t overestimate the ability of journalists to fabricate sensational stories from banal everyday facts.
But I can understand why they feel they have to do it.