Guest Post by Willis Eschenbach
I’ve written before about the study of Arthur Webb and Paul Kench regarding the fact that coral atolls are not being swallowed by rising seas. Their conclusion in that study was that the claims of sinking atolls were contradicted by the actual measurements of the islands in question. The measurements showed the islands were mostly either growing in size or staying the same (emphasis mine):
The results show that island area has remained largely stable or increased over the timeframe of analysis. Forty-three percent of islands increased in area by more than 3% with the largest increases of 30% on Betio (Tarawa atoll) and 28.3% on Funamanu (Funafuti atoll [the main atoll in Tuvalu – w.] ). There is no evidence of large scale reduction in island area despite the upward trend in sea level. Consequently, islands have predominantly been persistent or expanded in area on atoll rims for the past 20 to 60 years.
Well, the good news is that Paul Kench has not abjured his scientific habits. His latest study is entitled “Spatiotemporal variability of typhoon impacts and relaxation intervals on Jaluit Atoll, Marshall Islands” (paywalled here). Jaluit is in the tropical North Pacific. It is an atoll composed of a large number of small coral islets. From the Abstract (emphasis mine):
Jaluit Atoll in the Marshall Islands was struck by Typhoon Ophelia in A.D. 1958, causing significant geomorphic change to reef islands. Using aerial photographs as well as recent satellite imagery we track the impacts of the typhoon and the multidecadal recovery of islands. Ophelia caused a significant reduction in total land area of Jaluit Atoll, from 9.95 km2 to 9.45 km2 (–5.1%), with islands on the northeast rim collectively reducing in size from 4.72 km2 to 4.14 km2 (–12.2%). Between 1976 and 2006, 73 of 87 islands increased in size, with the total landmass exceeding the pre-typhoon area (10.25 km2).
In my post entitled “Floating Islands“, I described a coral atoll as being a momentary hesitation in a slow-motion river of coral sand and rubble. This river of sand and rubble is made up of broken-up bits of the reef that surrounds the atoll. The sand and rubble is constantly being driven by waves and storms and winds up onto the atoll … and at the same time the same storms are eroding the coral sand and rubble off the atoll and back into the ocean. The atolls exist in a dynamic balance between accretion and erosion.
The dynamic nature of the balance is well illustrated by the latest Kench study. A large cyclone came through in 1958, and blew some parts of these precarious piles of sand and rubble into the ocean. This reduced their size. But since the original conditions of oceanfloor topography and wind and wave still prevailed, the ocean merely piled new coral sand and rubble back up into the same locations, actively rebuilding the atoll islands in their previous locations on their previous foundations.
So no, the atolls are not in danger of being swallowed up by the ocean. To the contrary, they are constantly being rebuilt and repaired by the ocean. So … why are we receiving reports of trouble in paradise, of rising seas and eroding islands?
The reason is that when the reef is not healthy, the river of coral sand and rubble slows down … and since the atolls exist in a dynamic balance, any reduction in the amount of incoming coral sand and rubble will cause the atoll to erode away.
Generally, the reasons for the reef not being healthy boil down to a combination of overfishing, pollution, and coral mining. These are all solvable. In my post “Floating Islands” I laid out a whole host of things that the islanders can do to maintain the integrity of their atolls, along with the relevant links … but unfortunately, the fatuous idea that the islands are sinking is firmly embedded in the alarmosphere.
Which is why I am bringing all this up again. The “sinking atolls” meme is harder to kill than a vampire when you are fresh out of wooden stakes, with the New York Times flogging the same old dead horse once again, viz:
A Remote Pacific Nation, Threatened by Rising Seas
Climate change is threatening the livelihoods of the people of tiny Kiribati, and even the island nation’s existence. The government is making plans for the island’s demise.
By MIKE IVES
JULY 2, 2016
…
Nonsense. Horsefeathers. Greenrinsed insanity. Coral atolls are NOT threatened by rising seas, that is a sick fantasy.
Ah, well. One AM of a foggy night here, with a waning moon just risen and fighting hard to get through the mist. Keep fighting the good fight, dear friends, and stay well-stocked up with garlic and oak stakes … it’s gonna be a long one.
w.
My Usual Request: We can minimize misunderstandings by being specific. If you disagree with me or anyone, please quote the exact words you disagree with, so we can all understand the precise nature of your objections. I can defend my own words. I cannot defend someone else’s interpretation of some unidentified words of mine.
My Other Request: If you believe that e.g. I’m using the wrong method or the wrong dataset, please educate me and others by demonstrating the proper use of the right method or identifying the right dataset. Simply claiming I’m wrong about methods or data doesn’t advance the discussion unless you can point us to the right way to do it.
Further Reading On The Actual Kiribati Situation
So Many People … So Little Rain 2012-03-10
Well, I started a post on Kiribati, but when it was half written I found Andi Cockroft had beaten me to it with his post. His analysis was fine, but I had a different take on the events. President Tong of Kiribati says the good folk of the atolls are…
welcome back willis. great post. thank you. i too am a fan of paul kench’s excellent works on coral reefs. many of his papers are available on researchgate.net without a paywall.
and this one is available here, now, free and yarr!
Spatiotemporal variability of typhoon impacts and relaxation intervals on Jaluit Atoll, Marshall Islands
https://www.sendspace.com/file/7ovk5p
Thanks Willis, I just had an argument ( thankfully pleasant with a warmist family member), about the coral reefs and disappearing Pacific Islands you covered in previous articles. This one seems to be another nail in the coffin and I hope with a few more nails their ship will sink. ( your articles are like life rafts).
I just can’t resist an impulse to comment of the mixed metaphor of nails in coffins and sinking ships. By any chance have you been reading “Moby Dick” lately?
Should’ve carried on with Willis’ thoughtstream and said, “stake through the heart”.
“The atolls exist in a dynamic balance between accretion and erosion.” This is it in a nutshell. Over 1 year the change is a positive except when storms and surges happen, then it’s a net loss.
What will happen slowly over time (100s to 1000s of years) is the land area will grow, depending on the dynamics, things change slightly in groups of Islands because they affect each other in proximity which is why not all Islands are growing, some are being smeared out to water level, Very slowly, as in not something we’ll really measure in a lifetime.
sandbars are another example of this, the net gain is driven by the fact that the last of retreating water can pass through the deposits which will leave net gains, rather than taking the deposits back out to sea entirely
So often these issues come down to common sense and simple logic. Answer the simple question: Why are so many atolls so similar in elevation, geomorphology and geology?
Michael- they are similar because they evolved similarly. Atolls are the surviving fringe reefs of a subsiding volcano that has sunk beneath the waves.
A hotspot in the mantle creates a huge bulge in the crust of the earth (100s of meters vertical). Big shield volcanoes develop above the hotspot and you get islands like the big island of Hawaii. As tectonic motion pulls the island off the hotspot the volcano goes extinct and the island sinks. As it sinks, fringing coral reefs struggle to build upward to stay in the photic zone where their food is.
Look at each of the Hawaiian islands – the older the island the smaller- they are all subsiding as they slide further away from the hotspot that sourced them.
Sid,
Some 150 years ago, Charles Darwin demonstrated that coral islands had reef thicknesses of hundreds of meters as the reefs built up at the same rate as the extinct seamount volcanoes sank into the thin oceanic crust.
Your generalization is mostly true, except for the less major islands Molokai, Lanai, and Kahoolawe being smaller than Oahu and Kauai to their West. I am unsure if they were formed somewhat contemporaneously with Maui. Note: I’m leaving out the glottal stops and the associated ” ‘ ” for ease in typing.
Is it true the reef expands outward as the underlying seamount sinks?
Thomas Englert replying to Sid’s earlier comment
No. Not true. The Hawaiian ISland chain is formed from one specific hotspot (weak point) in the earth’s crust under the ocean. EVERY island to the west of today’s Hawaii (the big island) was formed EARLIER than it’s western neighbor, and LATER than its eastern neighbor – Midway the earliest of all those now above the sea surface. The SINGLE hotspot stays in place (relatively speaking) erupting at regular intervals as the crust moves westward over top of it. (If the eruptions were continuous, then you’d see a long chain of continuous mountains as in the western peninsula of Antarctica.) Steady erosion over the years wears down each high volcanic peak into lower and lower hills and then finally (as at Midway) only the beach sands are left above the water level.
“except for the less major islands Molokai, Lanai, and Kahoolawe being smaller than Oahu and Kauai to their West.”
This is a strictly temporary condition due to the current high interglacial sealevel. During normal (=glacial) conditions they are part of a single large island Maui-nui (Greater Maui).
RACookPE1978 “Midway the earliest of all those now above the sea surface.”
When I read the above something from my WW II history kept tickling my brain. Somehow I just knew there was another Island further west than Midway in the Hawaiian Chain so I looked into to it. Green Island in the Kure Atoll would actually be the earliest of the Hawaiian Islands formed by that hot spot that remains above the surface.
http://hawaiianatolls.org/about/kure.php
One only has to watch a Jellyfish being slowly pushed up onto a beach, each wave pushes it a little further and each retreating wave doesn’t have the kinetic energy to take it back out, retreating water has less force than an incoming wave which is why we have beaches and coral Atolls
You need a steeper incline for water to erode constantly, the angle of incline matters. Erosion happens worst when any material that incoming waves break off is free floating rather than being dragged out by retreating water, like cliffs for example. As such any loosed material is carried back out, it’s the reverse on an Atoll or beach
I’m sure Kirabati was being eroded due to construction during WW2 by the Americans building an airstrip and dredging the coral on the wind prone side of the island but I could be wrong .
They still dredge today so they can get ships in and out also when locals want fill they just break off the coral from where ever they want .
The whole island has recovered somewhat since ww2 because I’ve seen pics that show half of it gone during the war .
Any studies on land area changes in Kiribati, since it seems to be the atoll of most concern?
Dredging increases the incline, river bank erosion increases after dredging, however noticeable or not it is.
and of course, removing mangroves in Bangladesh has nothing to do with erosion either according to alarmists. It’s CO2’s fault
Robert from Oz ,
This was a problem in the Maldives back in the 1970’s By 1990 UNESCO flagged up that at this rate of coral being used for construction the coral would have disappeared in another 30 years. A ban was put on using coral for building. Probably the same for the other islands. The increase happened because of the surge in tourism from the 1970s onwards.
Hi fom Oz. An interesting comment from englandrichard about coral being used for building in the Maldives – here is an article by the Irish Examiner with a picture of the extent of building (!!!) in Maldives: http://www.irishexaminer.com/lifestyle/travel/bigread/a-taste-of-paradise-in-the-maldives-where-theocean-is-electric-blue-the-sand-sugary-white-388291.html
On this island at least there is literally not a spare square metre of land on which to build anything – just thousands of shops, hotels and apartment blocks. Amazing! I sometimes show this picture and a typical ‘tourist’ picture of just palm trees and sand, and ask the viewer which one is ‘the Maldives’ that they are worried about! No one has ever picked the one covered in hotels.
It has become apparent for many years now that FACTS have no affect on AGW myths & lies.
I have shown true believers a lot of data over the years, but nothing shakes their faith, especially the brain washed 20 somethings.
The reason for the lies & myths that are put forward daily along with the constant re-writing of historic data was shown on the Mike Carney thread, $7Trillion a year.
It make the Ponzi scheme look like really small potatoes.
Why itemise only coal mining? Reading Jim Steele yesterday it would seem that agricultural runnoff and silting were the worst offenders with crown of thorns starfish a close second.
Preds yes but not only that, corals compete too, environmentalists think they all just sit pretty and get along
I lived for a year in the Marshalls and I have been to Jaluit Atoll, one of the largest. Jaluit was the Atoll the Germans headquartered on before WWI. After the First World War the Marshall Islands became a Japanese League of Nations Mandate, they promptly and thoroughly militarized them.
One interesting feature of Jaluit’s beach was the nearly gone wreck of an iron-masted German Schooner.
Coral Atolls are very dynamic. Just as Willis’ post says, they are in constant change but they are both coming and going.
And as is the case with most things, the ecology of coral reefs is best characterized by what we don’t know, not our understanding.
“they promptly and thoroughly militarized them.”
Actually no. Despite contemporary claims the japanese did not build any military installations in the Mandate areas until after the expiration of the Washington/London treaties in 1935.
It’s strange that while most people accept Charles Darwin’s work on evolution, those same people seem prepared to ignore his theories on coral island development which match Willis’ .
I’ve seen stranger. People are not very educated on science, and go look iflscience to see how incredible political bias can be even when one values science.
Just like lefties are quick to point out Eisenhower’s farewell speech’s mention of “military-industrial complex” but not the rest of that thought. Why? Because they want expanded and more powerful government, just not the military part of it.
The CAGW memeplex is chock-full of memes and mini-memes, all of which just keep being repeated, robot-like by the Dim-stream Media, and regurgitated by mindless Believers. Facts simply do not matter to them so they simply reject them out of hand. They deny, deny, deny.
Bruce Cobb July 25, 2016 at 4:14 am
A distinction without a difference, Bruce.
Trying to understand atoll evolution without also taking into account sea floor subsidence rates will result in a very incomplete understanding of atolls. These structures exist BECAUSE the volcano beneath them is sinking. The rate of subsidence and the adaptive growth rate of the coral fringing reefs of the island is a delicate balance. If the reef is being pulled below the photic zone faster than it can grow upward it will drown and the atoll will sink. Relative sea level change is not generally of a magnitude to drown a reef.
If we assume that Hawaii is a typical coral island situation, the subsidence is measurable, but not extremely rapid. It seems to be about 2mm a year. If I haven’t misplaced a decimal point as I am all too prone to do, that’d be about 200m every 100,000 years. It seems likely to me that coral can keep up with that easily. http://link.springer.com/article/10.1007/BF02238084.
You forget that temperatures around Hawaii are rather marginal for corals and that the seafloor movement is steadily moving the islands into colder waters. The oldest “Hawaiian islands” are actually being subducted into the Aleutic trench at the moment.
Also note that during deglaciation subsidence + relative sea level rise get added to each other. Sooner or later there will be a deglaciation when the corals fail to keep up.
Actually there are a lot more reefs (“cayos”) just under the surfact than there are atolls. Though they will all come up again next ice-age.
It seems to be about 2mm a year.
==============
about what is claimed is due to sea level rise. however, sea level rise is not happening everywhere, while sea floor subsidence is.
we can see the subsidence for islands, yet we don’t stop to think that continents themselves may be subsiding under their massive weight. we assume that once the ice was removed, that continents rebound. but why should they? they are still heavier than the water that surrounds them, so they should subside.
Good points ferd. My impression is that the 1.9-2.4mm subsidence cited is after correction for SLR. But that seems awfully high given that it seems to work out to a couple of km subsidence per million years and there is still a bit of basalt above the water at French Frigate Shoals more than 1000km NW of the hot spot. May be that subsidence starts off high then falls off substantially after a few million years and a few hundred km of distance from the hot spot. Or I could simply have it all wrong.
The way I heard it, the continents are mostly less dense silicate rocks floating in a sea of denser mafic rocks. So they don’t sink. Seems plausible. Could be true.
Ferd berple: “we assume that once the ice was removed, that continents rebound. but why should they?”
With 2 km of ice on top, the land is more heavy during glacials and therefore subsides, as a cork in the thick syrup. Without the weight of ice, the same area rises thousands of years. In Scandinavia this rising is still happening:
“Sweden: The land of the rising coastline
The climate change threat to low-lying islands and cities is well known, but Scandinavia faces the opposite problem
A Stone Age camp that used to be by the shore is now 125 miles from the Baltic Sea. Sheep graze on what was the seabed in the 15th century. And Sweden’s port of Lulea risks getting too shallow for ships. In contrast to worries from the Maldives to Manhattan of storm surges and higher ocean levels caused by climate change, the entire northern part of the Nordic region is rising and, as a result, the Baltic Sea is receding.
The uplift of almost a centimetre a year, one of the highest rates in the world, is part of a geological rebound that has been taking place since the end of the Ice Age removed a vast ice sheet from regions around the Arctic Circle. “It’s a bit like a foam rubber mattress. It takes a while to return to normal after you get up,” said Martin Vermeer, a professor of geodesy at Aalto University in Finland. Finland gains 2.7 square miles a year as the land rises
(….) ”
Source: http://www.independent.co.uk/environment/climate-change/sweden-the-land-of-the-rising-coastline-8373787.html
“With 2 km of ice on top, the land is more heavy during glacials and therefore subsides, as a cork in the thick syrup. Without the weight of ice, the same area rises thousands of years. In Scandinavia this rising is still happening”
It depends a lot on just how viscous the syrup is. Iceland which is sitting on top of a low-viscosity hot-spot bobbed up and reached equilibrum in a few thousand years.
Scandinavia which is a Precambrian shield area with thick crust is still rising after 12 000 years, and so is Canada.
“Ah, well. One AM of a foggy night here, “…
Willis, should that be “ON a foggy night here, “, or is that just a different way of saying it ?
Seems like both could fit so I was curious…thanks.
The usual rule is that you don’t start a sentence with a numeral, so I assume “1” was spelled out accordingly.
As usual, good article. A point and a question.
Point: Reef material for coral islands is being manufactured constantly by coral polyps from Oxygen and Carbon Dioxide. For the most part it isn’t the low coral islands that are at risk from sea level rise — it’s low lying areas where there are no coral reefs. e.g. Louisiana, the Mid-Atlantic coast of the US, the Netherlands, etc. Facetious Suggestion: Perhaps the islanders who are not really at risk from sea level rise should be sending aid money to the folks in developed countries who are at risk.
Question: Evidence that the high stand of the last interglacial 120,000 years ago was more than 5m above current sea level is fairly convincing. So presumably the world’s coral reefs back then were in much the same place as now, but 5 or 6 meters higher. What happened when the glaciers formed and the seas receded? Did all the present reefs and islands become 100 meter (give or take a bit) high limestone islands and coastal plateaus? What happened to those hills during the next 80,000 years or so?
So the 100,000 year timeframe is a bit too recent for my own experience but in the geologic record there are many example of exactly this occurring. The limestone reef complexes are indeed uplifted and exposed to phreatic chemical erosion forming karst. The Capitan reef complex in Texas / New Mexico is a great example that you can walk through and in (this is the mechanism that gave birth to Carlsbad caverns).
Pinnacle reefs like these are also important targets for the oil industry because the karstification or erosion and fracture of exposed reefs often make great reservoirs for oil and gas.
I think Carlsbad is a hypogenetic cave, that is one being formed by rising fluids rich in H2S, not meteoric waters.
When sea rises, coral reefs build upward. When sea level falls during glaciation, coral reefs build outward following the sea.
“Did all the present reefs and islands become 100 meter (give or take a bit) high limestone islands and coastal plateaus?”
Yes. How do you think all those Floridian sinkholes and Bahamas “blue holes” originated? They are old karst cavities from times when the land stood higher.
By the way, such “raised” atolls exist today too: Henderson Island, Niue and Lifu are good examples.
Incidentally that evidence for 5-6 meters higher sea-levels is a lot shakier than you think.
In the early part of my oil industry career, I built processing facilities for oil and gas produced from pinnacle reef structures in northern Alberta. In the area of West Pembina, we drilled 8 or 10 reefs. They were a few miles apart and varied in size. Their average depth was 10k to 13k feet. The reefs looked like giant mushrooms in cross-section. They had begun as small reefs in an ancient sea, which rose quickly at first and then slowed so the reef tops could be a mile or more in diameter. The reservoirs were usually over pressured and the oil was light (40 API) but 13% H2S made it challenging. The carbonate reservoirs were easy to produce because of very high permeability and recovery ratios of more than 90% were possible with secondary water sweep and tertiary gas sweep. I guess you could say I started my career by getting educated by big mushrooms.
Sid
July 25, 2016 at 4:40 am
“Trying to understand atoll evolution without also taking into account sea floor subsidence rates will result in a very incomplete understanding of atolls.”
True, but incomplete. Probably you know that the Atolls we see today, had to keep up, through growth upwards of the coral, with ~120m of actual sea level rise since the glacial maximum, some 25,000yrs ago (plus seafloor subsidence). So these little critters haven’t faced anything they can’t handle.
I’d like to see a good article on the persistence of river deltas with rising seas. This is another alarmist poster child. Different mechanism but same result! The Ganges, Mississippi and all others pretty well duplicated the feat of the corals – they, too, grew ~120m with rising seas and any subsidence also gets them busy building up again. Now sea level DROP is a worry, both the coral and deltas are then chopped down by erosion as the sea level falls.
what I’ve noticed over the years is that coral reefs are typically highest on the windward side where they are bashed nearly continually by ocean waves. contrary to what people would normally assume. this is because corals grow fastest where wind driven waves are bringing them food. the waves occasionally do break off corals and drive this into the rubble pile behind the windward edge, causing the height of the reef immediately behind to also increase in height.
in contrast, the leeward edge of the reef is usually the lowest, with a large tail underwater that never rises much above the low water mark. again opposite what most people would assume.
Reef material for coral islands is being manufactured constantly by coral polyps from Oxygen and Carbon Dioxide.
=====================
interesting point. without CO2 there would be no coral reefs. the reefs themselves are made from air and seawater.
Ca + CO2 + 1/2 O2 == CaCO3
I don’t understand why metallic calcium is required to make calcium carbonate. After all, calcium metal has never existed naturally, and was only found on Earth when Humphrey Davy made it in 1803 by electrolysis of calcium chloride.
The correct equation is surely Ca(OH)2 + CO2 -> CaCO3 + H2O (Yes, I know it is an equilibrium, but I can’t find the double-headed arrow on my keyboard).
The earth’s oxygen is also being reduced by coral reefs and other shellfish, that are turning oxygen and CO2 into limestone. Thus we are at 21% oxygen today, why in the past in the time of giant insects it was 35% oxygen.
We are only a few percentage points oxygen above where fire becomes impossible. So if anything we should look at coral as the long term enemy of oxygen breathing animals.
…Or, we can look at CO2 as our friend….more CO2 = more plants = more Oxygen…
As always, the liberal left has it backwards….we need MORE CO2, not less..
Probably never over c. 30 % O2, vegetation becomes too flammable and thr fires draw down the oxygen. There is a LOT of fusain (fossil soot) in Carboniferous deposits.
Hopefully the increased greening due to interglacial warming and CO2 liberation will boost the oxygen some in the future.
Oops, meant that @ Ferd
There is here a confusion between the sedimentary portion of the atoll -the passive one- and the living reef that builds the rim, the active one.
Indeed, various storms, cyclones and waves do sculpt the coral rubble and sands around the islets distributed along the barrier. Cyclones waves are also known to have deposited large blocs of the living reef -bus size sometimes-, broken by waves onto the reef flat.
However, when one discusses the problem of atolls and relative sea level rise, it is the living reef that is telling the truth, its regression or its progradation or vertical accretion in response to relative sea-level changes. .
Detailed studies in some well drilled Pacific atoll have shown a complex stacking pattern of paleoecological succession of facies -that is from lagoonal to back reef to living crest to slope and then deep slope- during its Plio- Quaternary edification. Hence “on its seaward edge, the atoll is composed of a prograding system of fringing reefs, each edified during a period of sea-level rise”. The stacking pattern reflects the main global episodes of sea level rise or fall: for instance a reef assemblage dated around 15ky is found at a depth of 150m fringing a major reef complex dated 278ky located between 10 and 100m depth coinciding with the last glaciation.
See: Perrin C. CR Acad SciParis t 311 serie II p.671-678, 1990
If Darwin’s idea of overall volcanic subsidence remains valid, “Acquisition of atoll morphology has occurred by progressive differentiation between sheltered internal zones, where biodetrital sedimentation is dominant, and seaward edge characterized by organic construction”.
This also explains similarities of atolls barrier fracture networks observed around the Pacific.
TomRude July 25, 2016 at 9:10 am
Thanks, Tom, but there is in your comment a confusion regarding just who you are referring to. There is also a confusion about what it was that they said that makes you think that a confusion exists.
Please, folks, QUOTE THE EXACT WORDS YOU OBJECT TO so we can at least have a chance of knowing what it is that has you posting things like in this case that, while interesting, seem unrelated to what has gone before.
Many thanks,
w.
There is no confusion in my comment: simply put, this business of measuring areas sculpted by storms does little to really know the reef response to relative sea-level rise. Only coring data showing incremental shifts of established ecological zones along the atoll over let’s say a multi-secular period would really be telling. So the confusion I point out is between using detrital sediments versus observing organic construction shifts as an indication of the reef response to relative sea-level changes, a method advocated by these scientists and visibly endorsed in your post. That’s the gist of my comment and reference that is quite on topic.
I give up, Tom. That makes no more sense than your first comment. You say “this business of measuring areas sculpted by storms does little to really know the reef response to relative sea-level rise”.
You seem to misunderstand what is being measured. The claim has been repeatedly made that atolls are SHRINKING
Thanks, Tom, but I fear that makes no more sense than your first comment. You say “this business of measuring areas sculpted by storms does little to really know the reef response to relative sea-level rise”.
You seem to misunderstand what is being investigated. The claim has been repeatedly made that atolls are SHRINKING due to sea level rise and will soon disappear. How on earth could showing that the atolls are EXPANDING in a time of both rising sea levels and storm damage not be directly on topic and to the point?
Sure, it would be great to have other evidence, like drill cores … but that doesn’t make the measurements of the actual size of the atolls into non-evidence. The existing evidence adduced by Kench is more than sufficient to prove the point that the atolls are NOT in danger from sea level rise.
w.
OK I see. I am afraid you are talking about the size of emerged islets along the coral reef barrier and I am talking about the reef itself on which they stand (See Figure 2 of your first post “irony it burns”). The first are clearly impacted short term by meteorological conditions (storm damage, then normal currents recovery, variations of current intensity displacing biodetritic sediments around in relation to atmospheric circulation intensity, climatic oscillations that shift zones and intensity of predominantly high and low pressures etc…) while the second will mainly evolve in relation to longer term (multi-secular) relative sea level rise, as demonstrated in the Plio-Quaternary past, proof that reefs have adapted to far greater magnitude of changes in a recent past.
Notwithstanding the tectonic nature of these islands foundation since we could have islands in surrection (Makatea, Mataiva, Anaa for instance in Tuamotus -French Polynesia) sitting a few tens of kilometers away from regular atolls like Rangiroa.
In the end, alarmists’ claims are often simplistic and do confuse geographical and time scales to boot.
Thanks for the discussion.
Maybe the difference in emphasis between Willis and Tom can be explained like this:-
Politics says: Coral atolls are the place where people live – that is on the subaerial part of the structure – and this is shrinking due to erosion and sea level rise.
Geology says: Coral atolls are the place where corals live – this is where the real action takes place – on the submarine part of the structure – and this is growing due to accretion and an increase in the sequence strat accommodation space.
It is simple to be an alarmist and much harder to be a real scientist. Being a real scientist regarding sea level would require understanding of sedimentology and stratigraphy, being an alarmist requires the mental capacity of a parrot.
It’s hard to observe geologic processes as they unfold, it’s like watching the movie Titanic at 0.0001X speed. But it would appear to me that there is no beach, estuary, tidal flat, etc. that is currently showing the signs of a trangressive sequence, that is landward movement of depositional environments. Instead, we see sedimentation rates keeping pace with sea level (aggradational) or sedimentation rates outpacing sea level rise (progradational), as well as coast lines shifting landward or seaward due to local tectonic processes. The only thing you can scientifically conclude with this information is that there technically is NO global sea level rise currently taking place.
“ut it would appear to me that there is no beach, estuary, tidal flat, etc. that is currently showing the signs of a trangressive sequence, that is landward movement of depositional environments.”
Oh yes, there is. For example almost the whole southeastern coast of the US from New Jersey south is clearly transgressive with its typical rias (flooded river valleys) like e. g. the Delaware and the equally typical barrier islands.
Being an alarmist signals that you care, even if you really don’t. It also immunizes you somewhat from eco-nutters’ self righteous wrath and mental illnesses. Also, you get to point and shriek at the bad people, you know, those evil ones who must be overcome by any means necessary.
“Fools are made when neurosis meets an ideology that justifies the neurosis.”
“the atolls exist in a dynamic balance” That is true of course but due to fixed infrastructures (roads, houses) this natural process cannot operate any longer and eventually the roads and buildings on the islands will fall pray to the waves if sea level rise continues (at whatever rate). These islanders have adopted a life style (the Western one) that is not sustainable. They should have maintained their nomadic life style withn simple rebuidable huts etc.
imarcus
The sum of geological data since the Last Glacial Maximum shows that in the period of maximum rate of SLR, say from 18,000 to 8,000 years BP the global sea levels rose 130m, which according to my slide-rule is an average rate of 13mm per annum. Eyeballing the data suggests that for some 1,000 year periods it probably rose at ~20mm pa.
There is no suggestion from the geological record that the coral atolls we have now weren’t the ones that existed then which firmly suggests that coral reefs are well able to cope with either the Jason SLR rate of 3.2 mm pa or the reality check SLR rate of 2.2mm pa.
So what’s the fuss?
‘They’ dare not allow the gravy train to hesitate on its journey for one minute.
Well actually they didn’t have to grow at that rate, just migrate upslope. It was only near the end of the rise when the sea reached the (eroded) top of islands that coral growth actually needed to keep up with sea-level rise.
But didn’t someone once say they were capsizable? 😎
not surprising:
average coral reef growth: between 5 and 25 mm/year
average SLR: 3.2 mm/year according to JASON2 2.3mm/year according to tidal gauges
conclusion: coral grows faster then the sea level is rising, CAGW meming people pleasedo your homework even the island subsidence rate is covered by their growth rate
therefore this study result was an entirely logical outcome that doesn’t surprise me
You only have to change one word.
“Climate change (science) is threatening the livelihoods of the people of tiny Kiribati, and even the island nation’s existence. The government is making plans for the island’s demise.”
I’m coming late to this party, but
“Generally, the reasons for the reef not being healthy boil down to a combination of overfishing, pollution, and coral mining.”
Willis, repeat after me: “Generally, the reason for the reef not being healthy is that the ocean is turning into a boiling mass of Carbonic Acid, thanks to Man-Made CO2.”
Otherwise you will be investigated.
Every 110,000 years or so our planet warms up out of an ice age. Melt water pulses occur lasting 500 years where sea level increases by more than 5000 mm (18 feet) per century. That is about 20 times the current rate. Coral reefs have repeatedly shown over the eons that they can keep up.