Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


'Ice age blob' of warm ocean water discovered south of Greenland


New research published in Scientific Reports in February indicates that a warm ocean surface water prevailed during the last ice age, sandwiched between two major ice sheets just south of Greenland.

Extreme climate changes in the past Ice core records show that Greenland went through 25 extreme and abrupt climate changes during the last ice age some 20.000 to 70.000 years ago. In less than 50 years the air temperatures over Greenland could increase by 10 to 15 °C.

Greenland experienced several abrupt and brutal climate changes during the last ice age. But even during the coldest periods a blob of warm surface water existed nearby.

Credit: M. Sojtaric/CAGE/

However the warm periods were short; within a few centuries the frigid temperatures of the ice age returned. That kind of climate change would have been catastrophic for us today. (link)

Ice core records from Antarctica also show climate changes in the same period, but they are more gradual, with less severe temperature swings.

The Nature Scientific Report study shows that an area of the Nordic Seas, just south of Iceland, followed the Antarctic pattern of warming and cooling. Which is strange since it is so close to Greenland.

"We had expected to see sudden climate changes. But sediment core records from the area show that the climate changes here were actually gradual, and quite identical to Antarctic climate changes." says CAGE professor Tine Rasmussen, the principal author of the paper.

Gulf Stream holds the answers

Then, as now, the circulation of Atlantic Ocean, with currents such as the Gulf Stream, regulated transportation of heat to this area. Simply put, the surface currents transport heat from the southern and tropical Atlantic toward the North Atlantic.

" The Nordic seas between Norway and Greenland play a crucial role for the current patterns of the Atlantic Ocean. They act as a pump. Here the warm and salty surface water cools down during winter. It becomes heavy and is pumped down to the bottom before returning to the Atlantic, where it continues as a deep current all the way to the Antarctic region. " co-author Erik Thomsen from Aarhus University ( link) points out.

Without this pump, the north-south current system would slow down considerably. Changes in this circulation can have a profound impact on the global climate system.

During the ice ages this circulation was assumed to work as a seesaw in the playground - going up and down in opposite directions with an axis somewhere around the equator. The idea is that when it warmed in the north, it cooled in the south and vice versa. But Rasmussen and colleagues indicate another scenario.

Rewriting the seesaw hypothesis

During the coldest periods of the last ice age the Nordic seas were covered with a permanent layer of sea ice. The pump stopped transporting the heat northward. The heat accumulated in the southern oceans. However, the warming was not restricted to the south.

" Our results show that it continued all the way to Iceland. The warming was slow and gradual, and happened simultaneously in both hemispheres. Little by little the warm Atlantic water penetrated into the Nordic sea underneath the ice cover. It melted the ice from below. Once the ice was gone, the pump started up again, bringing additional warm water into the Nordic seas. And we got a warmer period for 50 years. " says Rasmussen.

Large ice sheets continued however, to cover the continents around the Nordic seas. In contact with the warm ocean water they started calving. This delivered icebergs and fresh water into the sea and caused a cooling down of the surface water. The seas were again frozen. And the pump slowed down.

The warm ocean blob of the ice ages rewrites the understanding of the ocean circulation systems, and how they affected the extreme climate changes of the past. The seesaw was actually more of a 'push and pull' system.

"There are no symmetrical processes in the north and the south - the climate changes were principally governed by simultaneous warming and the constant closing and re-opening of the sink pump in the Nordic seas" says Tine Rasmussen.

Media Contact

Maja Sojtaric


Maja Sojtaric | EurekAlert!

Further reports about: Antarctic CAGE Gulf Stream Hydrate climate changes ice age ocean water pump

More articles from Earth Sciences:

nachricht New technologies and computing power to help strengthen population data
22.03.2018 | University of Southampton

nachricht New interactive map shows climate change everywhere in world
22.03.2018 | University of Cincinnati

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Researchers Discover New Anti-Cancer Protein

An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.

The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Modular safety concept increases flexibility in plant conversion

22.03.2018 | Trade Fair News

New interactive map shows climate change everywhere in world

22.03.2018 | Earth Sciences

New technologies and computing power to help strengthen population data

22.03.2018 | Earth Sciences

Science & Research
Overview of more VideoLinks >>>