Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MU Scientist Uses Tracer to Predict Ancient Ocean Circulation

22.10.2008
Ancient water findings can be used to predict future changes during greenhouse conditions

Even though the Cretaceous Period ended more than 65 million years ago, clues remain about how the ocean water circulated at that time. Measuring a chemical tracer in samples of ancient fish scales, bones and teeth, University of Missouri and University of Florida researchers have studied circulation in the Late Cretaceous North Atlantic Ocean.

The Late Cretaceous was a time with high atmospheric levels of carbon dioxide and warm temperatures. Understanding such ancient greenhouse climates is important for predicting what may happen in the future. The new findings contradict some previous models.

Water masses are naturally imprinted with a chemical signature that reflects the geology in the land masses surrounding the area where they form. They carry this signature with them as they travel through the oceans, and the signature is recorded by fish skeletal material. If this fish debris is fossilized, so is the signature. MU and UF researchers collected 45 samples of 95- to 65- million-year-old fish debris from the Demerara Rise in the tropical western North Atlantic Ocean. They measured the chemical signature of these samples to estimate the source and circulation of intermediate waters during the Cretaceous Period.

“This technique allows us to track how water flowed in the Cretaceous oceans better than has been possible previously,” said Ken MacLeod, a professor of geological sciences in the MU College of Arts and Science. “Constraining ocean circulation patterns during greenhouse times, especially across the very large changes in the global carbon cycle that occurred during the interval we studied, is giving us a better understanding of how greenhouse oceans behave.”

Late Cretaceous atmospheric carbon dioxide levels were two to four times higher than today, which resulted in a greenhouse climate with tropical sea-surface temperatures rising to more than 34 degrees Celsius, 4 to 7 degrees Celsius (7 to 12 degrees Fahrenheit) warmer than today.

“The chemical signatures we measured presented two surprising findings. Values were extremely low for open-ocean sites for most of the time between 95 and 65 million years ago, but they were interrupted by a shift that was larger and more rapid than anything previously documented in marine sediments. This shift happened precisely at the time of the largest disturbance to the global carbon cycle of the past 200 million years,” MacLeod said.

Based on the results, the researchers proposed the Late Cretaceous North Atlantic was characterized by sinking of warm, salty, equatorial waters, and that circulation became more vigorous or a new source of the chemical signature was introduced at the time of the disturbance to the carbon cycle. Both the persistent formation of warm, saline intermediate waters and enhanced mixing contradict leading paleoceanographic models for these times.

Kelsey Jackson | EurekAlert!
Further information:
http://www.missouri.edu

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>