Featured Research

from universities, journals, and other organizations

Pollen Grain Study Yields New Picture Of Ice Age

Date:
December 30, 2008
Source:
Vetenskapsrådet (The Swedish Research Council)
Summary:
According to a new analysis 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.

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.

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.


Story Source:

The above story is based on materials provided by Vetenskapsrådet (The Swedish Research Council). Note: Materials may be edited for content and length.


Cite This Page:

Vetenskapsrådet (The Swedish Research Council). "Pollen Grain Study Yields New Picture Of Ice Age." ScienceDaily. ScienceDaily, 30 December 2008. <www.sciencedaily.com/releases/2008/12/081222113522.htm>.
Vetenskapsrådet (The Swedish Research Council). (2008, December 30). Pollen Grain Study Yields New Picture Of Ice Age. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2008/12/081222113522.htm
Vetenskapsrådet (The Swedish Research Council). "Pollen Grain Study Yields New Picture Of Ice Age." ScienceDaily. www.sciencedaily.com/releases/2008/12/081222113522.htm (accessed April 20, 2014).

Share This



More Earth & Climate News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Drought Concerns May Hurt Lake Tourism

Drought Concerns May Hurt Lake Tourism

AP (Apr. 18, 2014) — Operators of recreational businesses on western reservoirs worry that ongoing drought concerns will keep boaters and other visitors from flocking to the popular summer attractions. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) — Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) — Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Ark. Man Finds 6-Carat Diamond At State Park

Ark. Man Finds 6-Carat Diamond At State Park

Newsy (Apr. 18, 2014) — An Arkansas man has found a nearly 6.2-carat diamond, which he dubbed "The Limitless Diamond," at the Crater of Diamonds State Park. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins