Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antarctic icebergs -- Hotspots of ocean life

25.06.2007
Scientists cooperate to get close to floating islands of ice

Global climate change is causing Antarctic ice shelves to shrink and split apart, yielding thousands of free-drifting icebergs in the nearby Weddell Sea. According to a new study in this week’s journal Science these floating islands of ice – some as large as a dozen miles across – are having a major impact on the ecology of the ocean around them, serving as “hotspots” for ocean life, with thriving communities of seabirds above and a web of phytoplankton, krill, and fish below.

The icebergs hold trapped terrestrial material, which they release far out at sea as they melt. The researchers discovered that this process produces a “halo effect” with significantly increased phytoplankton, krill and seabirds out to a radius of more than two miles around the icebergs. They may also play a surprising role in global climate change.

“One important consequence of the increased biological productivity is that free-floating icebergs can serve as a route for carbon dioxide drawdown and sequestration of particulate carbon as it sinks into the deep sea,” said oceanographer Ken Smith of the Monterey Bay Aquarium Research Institute (MBARI), first author and principal investigator for the research.

“While the melting of Antarctic ice shelves is contributing to rising sea levels and other climate change dynamics in complex ways, this additional role of removing carbon from the atmosphere may have implications for global climate models that need to be further studied,” added Smith.

To understand the icebergs’ complex impacts, the multidisciplinary team of researchers carried out the most comprehensive study ever done of individual icebergs and their immediate environment, taking a wide array of measurements – physical, biological and chemical, and using satellite images provided by NASA.

At the same time, the wealth of data brought new challenges in how to manage this avalanche of information. “The whole is definitely greater than the sum of the parts, and to answer questions across the different areas from ecology to chemistry and climate, scientists need access to all the data,” explained researcher John Helly of the San Diego Supercomputer Center (SDSC) at UC San Diego who managed the data. “And we need to reliably harvest this information at sea, thousands of miles from our shore-based labs, and to preserve it as a unique snapshot of these iceberg ecosystems at this point in history.”

Using SDSC-developed technologies, Helly collected the data using the SIOExplorer-in-a-Box digital library system (http://SIOExplorer.ucsd.edu) and then stored the information in collections at SDSC for access and analysis by scientists now and in the future.

Just getting to the icebergs was a challenge. First the scientists used satellite images to select two icebergs to study in detail. Then they sailed aboard the Antarctic research vessel Laurence M. Gould to reach their targets in the remote Weddell Sea, an arm of the Southern Atlantic Ocean that cuts into the Antarctic continent southeast of Cape Horn. The icebergs in the study were up to a dozen miles long and more than 120 feet high, with one extending nearly 1,000 feet into the depths.

Despite the risks of getting close to these mountains of ice – which can shed huge pieces or overturn without warning – the scientists began their shipboard sampling mere hundreds of feet from the icebergs and continued out to a distance of some five miles, where the icebergs’ influence was no longer detectable.

“Phytoplankton around the icebergs was enriched with large diatom cells, known for their role in productive systems such as upwelling areas of the west coast of the U.S. or ice-edge communities in polar oceans. As diatoms are the preferred food for krill, we expect the changes in phytoplankton community composition to favor grazing as a key biological process involved in carbon sequestration around free-floating icebergs,” said oceanographer Maria Vernet from Scripps Institution of Oceanography at UC San Diego, one of the members of the research team.

“We used a small, remotely operated vehicle (ROV) to explore the submerged sides of the icebergs and the waters between the bergs and where the ship was, standing off at a safe distance,” said Bruce Robison of MBARI, an oceanographer and ROV pilot. “We flew the ROV into underwater caves and to the undersides of the icebergs, identifying and counting animals with its color video camera, collecting samples, and surveying its topography.”

Based on their new understanding of the impacts of the icebergs and their growing numbers -- the researchers counted close to 1,000 in satellite images of some 4,300 square miles of ocean -- the scientists estimate that overall the icebergs are raising the biological productivity of nearly 40 percent of the Weddell Sea’s area.

Paul Tooby | EurekAlert!
Further information:
http://www.sdsc.edu
http://SIOExplorer.ucsd.edu
http://www.mbari.org

More articles from Earth Sciences:

nachricht New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>