Re: Delta Digs Show Sea Is Rising
I haven't seen this article before now. Sometimes I forward articles
that are posted by others at P&C on to ClimateArchive, for easier
I noticed the statement that ...
> "Even if you take very grim scenarios projectingA one meter rise in sea level over the next 100 years is likely not the
> another one meter (3 feet) rise over the next 100
> years, we can prepare for it in that time or even
> less. But in the meantime, there is much to be
> done to gain a greater understanding of the basic
> process," [Torbj.., assistant professor at UIC]
worst case scenario. The next IPCC projection will likely have a faster
rise in sea level than the 2001 projections show, based on what is known
to be happening already, and evident in presentations made June 15, 2004
at the AAAS meeting in Washington D.C.
--------- Forwarded message ----------
From: "sonya koch"
To: "Paleontology_and_Climate" <Paleontology_and_Climate@yahoogroups.com>
Date: Sat, 31 Jul 2004 19:20:39 -0400
Subject: [P&C] Delta Digs Show Sea Is Rising
It would be nice if there was a scientific consensus on methodology in
collecting and analyzing this information. If someone has already posted
this, I apologize in advance, lol...........Sonya
Delta Digs Show Sea Is Rising (terradaily.com)
Chicago IL (SPX) Jul 28, 2004
Living in New Orleans means having to live with water. It's everywhere.
The city's elevation ranges from about 12 feet (3.65 meters) above sea
level to as much as six-and-a-half feet (2 meters) below sea level. Some
believe the city faces an ongoing battle against submersion by the rising
Gulf of Mexico.
New research reported by a team led by a University of Illinois at
Chicago earth scientist suggests the sea level in the lower Mississippi
delta near New Orleans has been rising at a steady pace for at least the
past 8,000 years, and is continuing to do so. The findings are published
in the July-August issue of the Geological Society of America Bulletin.
The proof is in the peat
Torbj?rn T?rnqvist, assistant professor of earth and environmental
sciences at UIC, and colleagues gathered core samples of deeply buried
peat from a swampy region of the Mississippi delta between Baton Rouge
and New Orleans. Samples from 29 sites were radiocarbon dated and then
plotted by age and altitude. The graph's curve shows a steady rise in sea
level in the lower delta region between the period of 3,000 and 8,000
Besides showing that rising sea levels are a continuing threat to coastal
areas of the Gulf of Mexico, T?rnqvist said the data challenges a
longstanding hypothesis that sea levels in the Gulf 5,000 years ago were
as much as two meters higher than they are today.
"We've found peat - organic deposits formed by plants that grew at sea
level - about 5,000 years old that are four meters below present sea
level. How is that possible?" he asked. "Based on our data, we strongly
suggest that the high sea level could not have happened."
The earlier notion stems from the presence of Gulf Coast beach ridges -
remnants of former shorelines - that now stand above sea level. Research
has shown some of these ridges to be about 5,000 years old. The
implication is that sea level has fluctuated, not risen steadily, as
T?rnqvist hopes to resolve the conflict by searching for and analyzing
peat deposits around the beach ridges. He's confident the results will
confirm that the ridges, however they were formed, do not prove that sea
levels were higher 5,000 years ago.
"This is important because it changes our model of how sea level has gone
from past to present for large areas of the Gulf Coast," said T?rnqvist.
"In order to make better predictions, we need to understand whether sea
level in the past was rising or falling."
Despite evidence that low-lying areas along the Gulf of Mexico face
steady erosion from a rapidly rising sea, T?rnqvist thinks public
officials have sufficient time to develop adaptive management strategies.
"Even if you take very grim scenarios projecting another one meter (3
feet) rise over the next 100 years, we can prepare for it in that time or
even less. But in the meantime, there is much to be done to gain a
greater understanding of the basic process," he said.
The study was co-authored by UIC doctoral student Juan Gonz?lez, Lee
Newsom of Pennsylvania State University, Klaas van der Borg and Arie de
Jong of Utrecht University in The Netherlands, and Charles Kurnik of the
University NAVSTAR Consortium, headquartered in Boulder, Colo.
The open-access general medical journal from the Public Library of
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