Ancient Rome's fish pens confirm sea-level fears

New Scientist ^ | 09:30 16 August 04 | Jeff Hecht

[ckilmer]

Ancient Rome's fish pens confirm sea-level fears

09:30 16 August 04

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Coastal fish pens built by the Romans have unexpectedly provided the most accurate record so far of changes in sea level over the past 2000 years. It appears that nearly all the rise in sea level since Roman times has happened in the past 100 years, and is most likely the result of human activity.

Sea-level change is a measure of the relative movement between land and sea surfaces. Tide-gauge records show that the sea level has been rising 1 to 2 millimetres a year since widespread measurements began around 1900, but do not pinpoint when the trend started.

Earlier sea levels can be estimated from geological data, but the accuracy is limited to about half a metre, which is not enough to precisely chart the history of sea-level rise.

So Kurt Lambeck of the Australian National University in Canberra turned to fish pens on the Tyrrhenian coast of Italy for a more accurate record of ancient sea level.

Ice age rebound

The Romans dug these fish pens into bedrock, and the water line in these well-preserved structures shows that the sea level along the Italian coast 2000 years ago was 1.35 metres below today's levels. "They were used for only a very short time, so they make rather nice markers," says Lambeck.

He then analysed how land elevations changed along the Italian coast due to both plate tectonics and the after-effects of the last ice age. In a paper to appear in the journal Earth and Planetary Science Letters, he concludes that geological processes pushed the land up by 1.22 metres over last two millennia, which means that the global sea level rose by 13 centimetres.

That is only about 100 years' worth of rise at the present rate of around 1 to 2 millimetres per year, implying that nearly all of it has occurred since 1900. While there is no proof that human activity is to blame, "I can't think of a natural process that would have started in 1900," he says.

The result "is a significant one", says Jonathan Gregory, who studies global changes in sea level at the University of Reading, UK. The finding supports the idea, based on the few tide-gauge records that extend back two centuries, that the rise in sea level did indeed accelerate about a century ago.

While Gregory cautions that this does not prove that global warming is responsible, both he and Lambeck agree that the results fit the rise in ocean volume expected from global warming melting glaciers in the industrial age.

Jeff Hecht

[wideminded]

Has anyone noticed the Tidal Basin in DC rearing up to swallow the national monuments in the last century ?

National Geographic published an interesting series of maps a few months ago that showed how there has actually been a lot of filling in since the Civil War and water originally came much closer to the White House.

[pdunkin]

A lot of you are scoffing at this report, but there may be something to it. Just recently, I visited some friends in Lubec, Maine and you would not believe how fast the ocean is rising there. In just the few short hours we were there, the ocean must have risen 15 feet. Scared me real bad. I haven't heard from my friends since I fled the area and I can only pray that they made it out alive before the rising ocean swamped their home.

[ckilmer]

sounds like they're not too far from the bay of fundy

[SunkenCiv]

Here's one:

Illarionov Attacks Britain, Vows to Bury Kyoto
The Moscow Times | 07/12/04 | Simon Ostrovsky

Posted on 07/11/2004 7:31:53 PM PDT by nypokerface

[SunkenCiv]

:')

[eyespysomething]

displacement

[calenel]

The CIA factbook agrees with me that virtually all (89%) of it sits on top of Antarctica

The portions resting on the bottom are already mostly underwater.

That depends. What about a mile thick ice sheet that is just entering the water? It won't be 'mostly' submerged until the water is at least half a mile deep. At that point 55% of the ice would replaced displaced water and 45% would contribute to a rise in sea level. The ice sheet won't leave the bottom and start floating (that is the point at which it ceases to affect sea level after melting) until it has reached a depth of about 9/10 mile.

If it melts -- that is, rises in temperature to the melting point -- the near-freezing liquid would cause a slight cooling and loss of volume in the world's oceans near the surface as it spread out, hence a slight loss of depth.

A negligible effect that would be more than offset by what ever caused the ice to melt in the first place. It can be totally discounted.

[Patton@Bastogne]

.


CKilmer

... he concludes that geological processes pushed the land up by 1.22 metres over last two millennia,


Now was that 1.220 meters or 1.2200000 meters ?

Sheesh !

I'd love to see you the Perfessor arrived (guessed) at those figures (LOL).


Patton@Bastogne


.

[jimtorr]

While it may be true that 89% of Antartic ice sits on land, 89% does not qualify as "virtually all". 11% is still a surprisingly large proportion. I didn't think it was quite that large.

BTW, the map is from the CIA fact book? You just can never tell what those guys have exhaustively investigated, or what they've ignored.

[MP5]

Must be local inbreeding.

LOL! Unfortunately, it affects us all though.

[calenel]

89% does not qualify as "virtually all".

Okay, fair enough. How about most or the vast majority? In any case, the ice is predominantly on land and I'd bet that most of the ice shelves are resting on the bottom where the water is not yet deep enough for it to float.

[SunkenCiv]

Just updating the GGG information, not sending a general distribution.

Please ping me to other topics which are appropriate for the GGG list. Thanks.

Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest -- Gods, Graves, Glyphs (alpha order)

[StopGlobalWhining]

Notice the lack of correlation between CO2 abundance and temperature.

[eeriegeno]

Sounds to me like someone has way too much time on his hands!!!!

[kabar]

Global Warming? What a load of poppycock!

[Larry Lucido]

Now stop that! I was just noticing how lame post #6 was and then realized it was me from a year ago!

[StopGlobalWhining]

Excellent post #95!

But this sort of evidence is ignored, either by those who believe the Kyoto Protocol is environmental gospel or by those who know 25 years of hard work went into securing the agreement and simply can't admit that the science it is based on is wrong.

It's even worse than that. It's not based on science at all, but politically correct social engineering that makes the assumption that the USA is evil because with only 4.5% of earth's population, we consume 25% of it's energy.

See post #41. Here's the full quotes from both of these less than honest influential individuals who pushed the Kyoto Protocol:

...the "noble lie" theory of leadership (ie: the elite must tell necessary lies to the masses to achieve desirable goals)

First, former Colorado Senator and Deputy Undersecretary of State Tim Wirth, who presently heads Ted Turners billion dollar fund to reduce world population:

"What we've got to do in energy conservation is try to ride the global warming issue," said Sen. Timothy E. Wirth, D-Colo., the Energy and Natural Resources Committee's point man on that issue and chairman of the Alliance to Save Energy. "Even if the theory of global warming is wrong, to have approached global warming as if it is real means energy conservation, so we will be doing the right thing anyway in terms of economic policy and environmental policy."

As reported in REPORTS - Less Burning, No Tears

By ROCHELLE L. STANFIELD, National Journal
© National Journal Group Inc.
Saturday, Aug. 13, 1988

---

Second: Climatologist Dr. Steven Schneider is a professor at Stanford and a member of the National Center for Atmospheric Research. He has recently criticized Danish Statistician Dr. Bjorn Lomborg for scientific dishonesty in Lomborg's book "The Skeptical Environmentalist".

But Schneider is hardly a paragon of scientific integrity. In a now famous interview in the October 1989 issue of Discover magazine, Schneider showed his true colors:

On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but - which means that we must include all the doubts, the caveats, the ifs, ands and buts.

On the other hand, we are not just scientists but human beings as well. And like most people, we'd like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climate change.

To do that, we need to get some broad-based support, to capture the public's imagination. That, of course, entails getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. Each of us has to decide what the right balance is between being effective and being honest.

[Alouette]

STATE OF FEAR

[SunkenCiv]

Thanks TomServo for the ping. Perspective? During the Medieval Warming period, various towns which are today landlocked, miles from the sea, had docks and direct access via fjords and whatnot. Sometime after the Little Ice Age (Medieval Cooling) began, sealevel fell, and it hasn't budged since 1850.

To all -- please ping me to other topics which are appropriate for the GGG list. Thanks.

Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest -- Gods, Graves, Glyphs (alpha order)

[SunkenCiv]

Oops, sorry TomServo, I just noticed the ping was from last year, and the current ping was a bttt from Larry.

My apologies also to the rest of the ping list for the duplicate ping job from this topic, which after all has been submerged by hundreds of subsequent ones. ;')