Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Melting of the Greenland ice cap may have consequences for climatic change

08.05.2007
The magnitude of possible climate change in the future will depend to a large degree on the response of ocean circulation to global warming, as the ocean currents distribute an immense quantity of heat around our planet and, besides, determine levels of humidity and energy. Any variation in ocean circulation may lead to substantial and abrupt climate changes (that is to say over less than 30 years) on a global scale.

Deep ocean sediments offer a record of ocean circulation in the past. By studying these sediments, we can see that abrupt changes in ocean circulation and the subsequent climate change are not a new phenomenon, but have happened on several occasions in the past. When the great ice sheets covering North America and Scandinavia melted at the end of the last ice age, the subsequent flow of fresh water into the North Atlantic caused the greatest natural disturbance in ocean circulation in the last 20,000 years. This episode provides an excellent model to examine the relation between ocean disturbance and climate instability.

According to a revision article published in Science, ocean circulation during the last ice age was very different to present day circulation. The formation of deep water currents in the North Atlantic was much weaker and the flow of warm water from the Gulf Stream decreased. This led to a cooling of the northern hemisphere and contributed to the formation of the great ice caps which covered North America, Scandinavia and Europe.

In a similar study, the marine sediments of the North Atlantic were observed in order to document the sequence of events that led to that disturbance. The melting caused a significant decrease in the Gulf Stream, which transports warm water from the Gulf of Mexico to the North. This submerged the region of the North Atlantic into a period of glacial cold which lasted at least 1,200 years.

Nevertheless, the slowing down of the ocean circulation in the North Atlantic began about 700 to 1,200 years before this great melting of the ice caps and the subsequent flow of fresh water into the ocean took place. The very first stage of this change coincided with brief and isolated periods of melting of the small British Ice Sheet (BIS). The authors of the study have come to this conclusion from an observation of the fine layers of sediment (formed by grains of quartz) coming from successive waves of icebergs which, when they melted dumped their load of sediments onto the sea bed. These icebergs came from the edges of the ice which surround and stabilised the BIS.

These results show that the disturbances caused by melting may in turn cause substantial changes in ocean circulation without the need for a catastrophic dumping of fresh water. This seems to indicate that an acceleration in the melting of the Greenland ice cap, could, in fact, play a key role in the future stability of ocean circulation and climate change in the whole North Atlantic region.

Octavi López Coronado | alfa
Further information:
http://www.uab.es

More articles from Earth Sciences:

nachricht Climate change in a warmer-than-modern world: New findings of Kiel Researchers
24.04.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Tiny microenvironments in the ocean hold clues to global nitrogen cycle
23.04.2018 | University of Rochester

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Complete skin regeneration system of fish unraveled

24.04.2018 | Life Sciences

Scientists create innovative new 'green' concrete using graphene

24.04.2018 | Materials Sciences

BAM@Hannover Messe: innovative 3D printing method for space flight

24.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>