Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dramatic climate changes in the last Ice Age

11.04.2007
Enormous ice sheets melted in the middle of the last Ice Age. Land areas that had been depressed by the ice were inundated. The sea level rose very rapidly. In some large river valleys in north-western Russia, the sea reached 200-300 kilometres further into the country than it does today.

”The climate 60 000 years ago was cooler than today, but the vigorous melting of large ice masses in America and the Antarctic gave a chain reaction all the way to the Barents Region,” Eiliv Larsen, a geologist at the Geological Survey of Norway (NGU), tells us.

He says that scientists have always known that large natural variations in climate took place during glaciation periods, both between separate ice ages and within each individual ice age. Now the Earth is faced with an additional challenge; global warming caused by man.

Changing oceans

”The ice in the Barents Sea began to float and break up in response to the rising sea level 60 000 years ago. It became thinner and rapidly melted completely. Enormous volumes of meltwater poured into the sea, and large glacial lakes were drained. The huge quantities of freshwater had a great influence on the circulation in the oceans and on the climate,” Eiliv Larsen says.

Eiliv Larsen is one of Norway’s foremost researchers on ice-age history and climate variability. Among other things, he is now in charge of the SciencePub project, which, during the International Polar Year, will be studying the natural variations in climate and the environment in the Arctic during the last 130 000 years. Researchers will also be examining how mankind succeeded in adapting to these changes.

Enormous ice masses

When the glaciers had their greatest extent during the last Ice Age, the vast ice sheet had its western limit on Andøya in north-western Norway. The ice stretched some 1500 kilometres southwards to Hamburg, northwards right up to the Arctic Ocean, and the eastern limit was far away in Russia. The enormous, up to 3000-metre-thick ice sheet, covered both land and sea. So much water was bound up in the ice that the oceans stood 120-130 metres lower than today.

”The incredible changes in the physical natural environment during the last glacial period are a result of natural climatic changes on the Earth. Ice ages have come and gone with ordered regularity caused by variations in the solar radiation reaching the Earth,” Eiliv Larsen emphasises.

Human influences

Now that the Earth is also encountering human impacts on the climate, it is no longer just a matter of small, cyclic changes in the Earth’s orbit round the Sun, its angle of inclination and the slow rotation of the Earth’s axis. Mankind has created great uncertainties in the dynamic natural variations in climate.

”But what does this really mean?”

”In the long term, the natural trend is towards a colder climate, but we will scarcely encounter a real ice age before some 50 000 years hence,” Eiliv Larsen believes. “We now live in a period with a limited extent of ice. The exceptions are Greenland and the Antarctic, where there is almost as much ice as during the glacial period. Glaciers are, nevertheless, retreating now in response to the warmer climate. Global warming brought about by man may continue for many centuries, until all the fossil fuels have been used up. Norwegian glaciers are obviously at risk in this perspective,” Eiliv Larsen says.

By Gudmund Løvø

Eiliv Larsen | alfa
Further information:
http://www.ngu.no

More articles from Earth Sciences:

nachricht From volcano's slope, NASA instrument looks sky high and to the future
27.04.2017 | NASA/Goddard Space Flight Center

nachricht Penn researchers quantify the changes that lightning inspires in rock
27.04.2017 | University of Pennsylvania

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>