Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




ICE WORLD
Antarctic icebergs help the ocean take up carbon dioxide
by Staff Writers
Monterey Bay CA (SPX) May 12, 2011


Icebergs such as this one carry iron-rich sediment from Antarctica out into the Southern Ocean. The darker parts of the ice contain higher concentrations of sediment. Image: Debbie Nail Meyer 2009 MBARI

The first comprehensive study of the biological effects of Antarctic icebergs shows that they fertilize the Southern Ocean, enhancing the growth of algae that take up carbon dioxide from the atmosphere and then, through marine food chains, transfer carbon into the deep sea.

This process is detailed in 19 new research papers published electronically in a special issue of the journal Deep Sea Research Part II: Topical Studies in Oceanography.

The research team was led by MBARI marine biologist Ken Smith and funded by the National Science Foundation. Smith, along with researchers from more than a dozen other institutions, conducted three month-long cruises to the Weddell Sea in 2005, 2008, and 2009.

By tracking individual icebergs and deploying remotely controlled aircraft and submersibles, as well as robotic drifters, the team was able to document a process that had previously been suspected, but never proven.

Global climate change is causing Antarctic ice shelves to shrink and split apart, releasing thousands of free-drifting icebergs that are carried by currents into the nearby Weddell Sea. The new research suggests that these icebergs carry iron-rich sediment from the land out into the ocean.

As these icebergs melt and drift across the ocean, some of the iron dissolves in the seawater, creating a trail of iron-rich meltwater that can be up to 19 kilometers (12 miles) long. The iron in this water helps fertilize the growth of microscopic algae.

During their three cruises, the team studied an area they called "iceberg alley" in the inhospitable and sometimes dangerous Southern Ocean. Instead of avoiding icebergs, they directed their research vessel to approach and follow drifting icebergs the size of small towns.

To follow individual icebergs, they used satellites and GPS tracking devices that were dropped on the icebergs using a radio-controlled airplane. They also used three different robotic submersibles to study life on the undersides of the icebergs.

MBARI engineers, led by Alana Sherman, developed a new robotic instrument that was programmed to sink 600 meters (about 2,000 feet) below the ocean surface while a large iceberg drifted overhead, then rise back to the sea surface after the iceberg had passed.

This instrument, called a "Lagrangian sediment trap," was used to collect particles of sediment, bits of dead algae, and other debris that drifted down from the waters under and around the iceberg. This device allowed scientists to measure, for the first time, the amount of organic carbon sinking into the deep sea beneath a large (6-kilometers wide, 35-kilometers long, and 28-meters tall), free-floating iceberg.

The researchers compared the amount of carbon sinking down to 600 meters beneath the iceberg with the amount of carbon sinking in the open ocean nearby. They found that about twice as much carbon sank into the deep sea within a 30-kilometer (18.6-mile) radius of the iceberg, compared with an open-ocean "control" area.

Extrapolating their findings to the rest of the Weddell Sea, the researchers concluded that the icebergs (both large and small) were playing an important role in controlling how much carbon from the atmosphere was taken up by algae and ultimately transported into the deep sea. "The role of icebergs in removing carbon from the atmosphere may have implications for global climate models that need to be further studied," said Smith.

In addition to the direct measurements of material sinking beneath the icebergs, the multidisciplinary research team performed a wide variety of physical, chemical, and biological studies around the icebergs. Many of these studies are detailed in the special issue of Deep-Sea Research. The 19 papers in this special issue describe:

+ New methods and tools for tracking icebergs from a moving ship at sea

+ Water-sampling and video surveys by remotely operated vehicles

+ Aerial surveys and tracking of icebergs using radio-controlled aircraft

+ The fresh water, iron, and sediment released by melting icebergs

+ The design and operation of the Lagrangian sediment traps, and the amounts of debris, organic carbon, and other materials collected by these traps

+ Populations of marine microbes, algae, marine animals, and seabirds around the icebergs

After overcoming many challenges to study a few icebergs, Smith and Sherman are working on strategies and automated tools for measuring the effects of the many icebergs in "iceberg alley" over periods of months to years. This would provide a much better estimate of how icebergs are affecting the chemistry and biology of the Southern Ocean.

Research Journal: Ken Smith (ed.), Free-Drifting Icebergs in the Southern Ocean, Deep Sea Research Part II: Topical Studies in Oceanography, Volume 58, Issues 11-12, Pages 1277-1504 (June 2011).

.


Related Links
Monterey Bay Aquarium Research Institute (MBARI)
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
Calling all candidates for Concordia
Paris (ESA) Apr 26, 2011
They are more cut off than the crew of the International Space Station. They are at Concordia in Antarctica, and one of them is ESA researcher Eoin Macdonald-Nethercott. If you want to follow in his footsteps, ESA is looking for his successor. The flat landscape around the Concordia research station is 3200 m above sea level and virtually inaccessible from February to November. During the ... read more


ICE WORLD
Space Adventures proposes modified Soyuz TMA for Lunar tourists

BRP To Contribute To Canadian Moon And Mars Exploration Programs

Naveen Jain Co-Founder And Chairman Of Moon Express

Project Morpheus To Begin Testing At NASA's Johnson Space Center

ICE WORLD
Mars Express Sees Deep Fractures on Mars

Opportunity Images Small Craters

Exploring Rio Tinto Eurobotically

NASA Orbiter Reveals Big Changes in Mars' Atmosphere

ICE WORLD
Texas Space Alliance Celebrates New Space "Tourism" Law

AFIT education paves way to space

Soyuz launch from Europe space base set for October

NASA, Space Community Remember 'Freedom 7'

ICE WORLD
Top Chinese scientists honored with naming of minor planets

China sees smooth preparation for launch of unmanned module

China to attempt first space rendezvous

Countdown begins for Chineses space station program

ICE WORLD
Andrews Space Delivers Cargo Module Power Unit for Orbital's Cygnus Spacecraft

ISS orbit to be readjusted for Soyuz TMA-20 return

Soyuz is in the launch zone at Europe's Spaceport

Progress Docks To ISS

ICE WORLD
ST-2's installation on SYLDA marks the start of final payload integration for Ariane 5's next mission

Arianespace to launch ABS-2 in 2013

GSAT-8 put through its paces

Ariane Ariane 5 enjoys second successful launch for 2011

ICE WORLD
Flipping Hot Jupiters

What a scorcher: 'Hot Jupiter' puzzle explained

An Earth as Dense as Lead

Astronomers unveil portrait of 'super-exotic super-Earth'

ICE WORLD
Mayflower Test Satellite Proves Successful During Recent SpaceX Mission

Google notebooks challenge Microsoft

Broadband Lidar Instrument Successfully Tested on NASA's DC-8

Russia says fire put out near radioactive facility




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement