Posted on 08/16/2004 5:06:16 AM PDT by 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
The crew has been informed they are to cease ****ing off the side of the ship.
Ditto!
How'd they prove that? How do they know it's not the result of, say, increased polar bear voiding into the ocean?
"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... 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."
Huh. I didn't know there were only ONE HUNDRED millimeters in a meter... ;')
If you read further, you'd find that 1.22 meters were accounted for by natural uplifting. Only 13 centimeters (130 mm) can be attributed to a rise in sea levels.
Nowhere does it say that 89 per cent of the ice is on the continent. Reason? Because it isn't.
http://www.odci.gov/cia/publications/factbook/geos/ay.html
"14 million sq km (280,000 sq km ice-free, 13.72 million sq km ice-covered... about 98% thick continental ice sheet and 2% barren rock, with average elevations between 2,000 and 4,000 meters; mountain ranges up to nearly 5,000 meters; ice-free coastal areas include parts of southern Victoria Land, Wilkes Land, the Antarctic Peninsula area, and parts of Ross Island on McMurdo Sound; glaciers form ice shelves along about half of the coastline, and floating ice shelves constitute 11% of the area of the continent... the lowest known land point in Antarctica is hidden in the Bentley Subglacial Trench; at its surface is the deepest ice yet discovered and the world's lowest elevation not under seawater..."
Hmm. I'm no expert (except maybe in Roman fisheries) but this raises a lot of questions. How is anyone to gauge by inches the rise of sea level based on a few fish pen markers, in a land of considerable tectonic activity---and not much going on in the way of tides? (This isn't the Atlantic they're talking about, it's the Mediterranean.) Seems to me such marks could have been affected more by the stock of fish than by the minimal Med tide.
This report stinks like garum. (Paste made from pickled, fermented fish guts, much loved by Romans.) Unbelievably sloppy science, ie, no science.
This is so stupid because the coasts, everywhere are in a constant state of flux and change. Where we live the mouth of a river has been filling with silt, over thousands of years, filling the bay and creating a spit of land that reaches out toward Canada like a finger. The bay is now nothing more than a tidal sand flat.
SGW
Totally ignores quite conclusive opposing data from New Zealand.
And Great Britian
It's the same line.
Humans are evil and are the cause of every bad thing on earth. The only solution is to not have humans.
I want global warming. I am negotiating with the the Canadian Citrus Growers Council to plant vast acreages of oranges near Montreal.
I will own the entire fresh orange market in the northeastern United States.
Of course most of Florida will be under water but they will have at least 5 years to move.
"As some of you may know, I have spent the last several years exploring various environmental issues, particularly global warming. I have been deeply disturbed by what I have found, largely because the so-called evidence for so many environmental issues is often shockingly flawed and unsubstantiated."
"But more troubling, to me, is the degree to which the political process seems to have captured and often corrupted the integrity of the scientific research that is used to formulate policy, and inform policy decisions."
So, let me get this straight, in 2000 years the land has risen 122 Centimeters (all of this by some natural means)... and the water has risen in that same amount of time 13 centimeters (all of this because of man).... Oh yea... We got a big problem... NOT.
His conclusion on the water is based upon his conclusion on the land... either of which could be wrong, incorrectly timed, or flat out poppycock....
Wake me when the world floods... I'm sick of this loonieness.
Thanks J, I did see that. Looks like the 13 cm are also part of the natural uplift, but are falsely attributed to sea level rise.
I'm reading it now. Crichton really rips the enviro-whackos, and also Hollyweird.
Too bad they will never make it into a movie.
[ big snip]
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.
13cm rise from human activity = a whole lotta Pee in the pool . . .
I have seen the Washington Monument and Jefferson and Lincoln Memorials surrounded by water, but those were hurricane related Potomac floods.
Today it is landlocked.
The sealevel is so much lower that what was the roman military port is now a park in the center of town.
Meanwhile a hundred miles up the coast, Venice is sinking.
All the change in sealevels means is that Italy is tectonically active and parts of it have moved in one direction of the other over time.
SO9
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