Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ice sheets caused massive sea level change during late Cretaceous

01.03.2004


Period was previously thought to be ice-free



Arlington, Va.-Scientists using cores drilled from the New Jersey coastal plain have found that ice sheets likely caused massive sea level change during the Late Cretaceous Period -an interval previously thought to be ice-free. The scientists, who will publish their results in the March-April issue of the Geological Society of America (GSA) Bulletin, assert that either ice sheets grew and decayed in that greenhouse world or our understanding of sea level mechanisms is fundamentally flawed.

Led by Kenneth Miller of Rutgers University, the scientists examined cores from Ocean Drilling Program Leg 174AX, an onshore extension of an offshore expedition. They found indications that sea level changes were large (more than 25 meters) and rapid (occurring on scales ranging from thousands to less than a million years) during the Late Cretaceous greenhouse world (99- 65 million years ago).


"The onshore-offshore drilling forms a important, coordinated link to study the history of sedimentation along this area of the U.S. continental margin," said Leonard Johnson, director of the National Science Foundation (NSF)’s continental dynamics program, which co-funded the research with NSF’s ocean drilling program.

Analyses indicate minimal tectonic effects on the New Jersey Coastal Plain at this time, the scientists say. The other explanation for such large, rapid changes is the waxing and waning of large continental ice sheets, they maintain. What is perplexing, however, is that such large and rapid sea-level changes occurred during an interval thought to be ice free.

"Our studies of cores in New Jersey provide one of the best- dated estimates of how fast and how much sea level changed during the greenhouse world of the Late Cretaceous," said Miller. "The Earth was certainly much warmer at that time, probably due to high carbon dioxide levels in the atmosphere. At the same time, our estimates require that ice sheets grew and decayed on Antarctica during this period of peak warmth, which has been a previously heretical view."

The scientists propose that the ice sheets were restricted in area to Antarctica and were ephemeral. The ice sheets would not have reached the Antarctic coast, explaining the relative warmth in Antarctica, but still could significantly alter global sea level.

Cheryl Dybas | NSF
Further information:
http://www.nsf.gov/home/news.html

More articles from Earth Sciences:

nachricht Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck

nachricht Supercomputing helps researchers understand Earth's interior
23.05.2017 | University of Illinois College of Liberal Arts & Sciences

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>