Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global warming doubles rate of ocean rise

28.11.2005


Rutgers-led team shows rising ocean levels tied to human-induced climate change

Global ocean levels are rising twice as fast today as they were 150 years ago, and human-induced warming appears to be the culprit, say scientists at Rutgers, The State University of New Jersey, and collaborating institutions.

While the speed at which the ocean is rising – almost two millimeters per year today compared to one millimeter annually for the past several thousand years – may not be fodder for the next disaster movie, it affirms scientific concerns of accelerated global warming.



In an article published in the Nov. 25 issue of the journal Science, Rutgers professor of geological sciences Kenneth G. Miller reports on a new record of sea level change during the past 100 million years based on drilling studies along the New Jersey coast. The findings establish a steady millimeter-per-year rise from 5,000 years ago until about 200 years ago.

In contrast, sea-level measurements since 1850 from tidal gauges and more recently from satellite images, when corrected for land settling along the shoreline, reveal the current two-millimeter annual rise. "Without reliable information on how sea levels had changed before we had our new measures, we couldn’t be sure the current rate wasn’t happening all along," said Miller. "Now, with solid historical data, we know it is definitely a recent phenomenon.

"The main thing that’s changed since the 19th century and the beginning of modern observation has been the widespread increase in fossil fuel use and more greenhouse gases," he added. "Our record therefore provides a new and reliable baseline to use in addressing global warming."

The new sea level record spanning 100 million years of geologic time is the first comprehensive one scientists have produced since a commercial research endeavor in 1987, which, according to Miller, was not fully documented and verifiable.

The findings by Miller’s team argue against some widely held tenets of geological science. Miller claims, for example, that ocean heights 100 million years ago and earlier were 150 to 200 meters lower than scientists had previously thought. Changes at these levels can only be caused by the Earth’s crust shifting on the ocean floor. Miller’s findings, therefore, imply less ocean-crust production than scientists had widely assumed.

During the Late Cretaceous period (the most recent age of dinosaurs), frequent sea-level fluctuations of tens of meters suggest that the Earth was not always ice-free as previously assumed. Ice-volume changes are the only way that sea levels could change at these rates and levels, Miller claims. This suggests small- to medium-sized but short-lived ice sheets in the Antarctic region, and casts doubt whether any of the Earth’s warmer eras were fully ice-free.

Miller’s team took five 500-meter-deep core samples of sediments onshore along New Jersey’s coastline from Cape May to Sandy Hook. The scientists examined the sediment type, fossils, and variations in isotopes, or different forms of the same elements, at different levels in the cores they extracted. Miller also correlated these measurements with others from throughout the world to substantiate the global nature of their record.

The Rutgers study included participants from the New Jersey Geological Survey, the Lamont-Doherty Earth Observatory of Columbia University, Western Michigan University, the University of Oregon and Queens College in Flushing, N.Y. The National Science Foundation provided major funding for the study.

Carl Blesch | EurekAlert!
Further information:
http://www.rutgers.edu

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>