Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study of pollen grains yields new picture of Ice Age

22.12.2008
According to a new doctoral dissertation at Stockholm University in Sweden, based on analyses of deposits of pollen grains, it is possible that all of Sweden was virtually free of ice for long periods during the latest ice age.

The findings show that the glaciation might have started some 20,000 later than was previously assumed.

"It's important that we get to the bottom of when the great ice sheets covered Sweden and how warm it might have been when there was no ice. At present there are two extremely different hypotheses, which makes it difficult to study how the ice age climate relates to various parameters in the climate system, such as the earth's relation to the sun," says Martina Hättestrand, a doctoral candidate at the Department of Physical Geography and Quaternary Geology, Stockholm University.

In order to understand the climate system of the earth, researchers today are studying the climatic variations of ice ages. Since we have the most land forms and geological traces preserved from the latest ice age, much of the research focuses on that particular period. An important aspect of the research is to study when the huge continental ice sheets grew and when they melted away, and to study the environment and climate of the areas that were free of ice. The size and movement patterns of the ice sheets can be calculated by studying land forms and moraine deposits. The ice-free periods can be studied by pollen analysis, among other methods. Pollen analysis is a method in which scientists use pollen grains preserved in ancient sediment to create a picture of what plants once grew in the area and what the climate was like.

Martina Hättestrand's dissertation is based on studies of pollen grains that were deposited more than 40,000 years ago in small lakes during the ice-free phases of the latest glaciation. During the warm phases of the Ice Age, high amounts of birch pollen were deposited, which indicates that summer temperatures were around 10 degrees centigrade in northern Sweden. During cold ice-free phases, mostly grass and herbal pollen was deposited.

"The findings from my dissertation indicate that the first icing up phase of the latest Ice Age may in Scandinavia have started about 95,000 years ago - which is some 20,000 years later than was previously thought," says Martina Hättestrand.

According to the previously accepted hypothesis, Sweden was covered with ice 75,000-20,000 years ago. Martina Hättestrand's hypothesis, on the other hand, is that Sweden may have largely been ice-free between 59,000 and 40,000 years ago. If this is true, the last ice sheet of the Ice Age formed much more rapidly than was previously believed in order to have reached all the way down to northern Germany during the maximum phase about 22,000 years ago.

For further information:
Martina Hättestrand, Department of Physical Geography and Quaternary Geology, Stockholm University, e-mail: martina.hattestrand@geo.su.se; cell phone: +46 (0)70-318 30 32
Pressofficer Maria Erlandsson; maria.erlandsson@kommunikation.su.se;
+46(0)70-230 88 91;For pictures please contact: press@su.se or phone +46 (0)8-16 40 90
Facts:
The latest Ice Age is called the Weichselian glacial (glaciation) in northern Europe. It started roughly 120,000 years ago and ended about 10,000 years ago. The definition of an ice age is that it has a colder climate than an interglacial period, which is the type of climate we live in today. The climate varied a great deal during the ice ages.

Maria Erlandsson | idw
Further information:
http://www.vr.se

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

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

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

27.04.2017 | Earth Sciences

Control of molecular motion by metal-plated 3-D printed plastic pieces

27.04.2017 | Materials Sciences

Move over, Superman! NIST method sees through concrete to detect early-stage corrosion

27.04.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>