Featured Research

from universities, journals, and other organizations

Warmer Periods In Alaskan Area Not Confined To Modern Times

Date:
August 21, 2001
Source:
University Of Illinois At Urbana-Champaign
Summary:
In the northwest foothills of the Alaska Range, the last 150 years have been warm by historical reckoning, scientists report. However, they note, two other lengthy periods of climatic warmth appear to have occurred in that region during the last 2,000 years.

CHAMPAIGN, Ill. — In the northwest foothills of the Alaska Range, the last 150 years have been warm by historical reckoning, scientists report. However, they note, two other lengthy periods of climatic warmth appear to have occurred in that region during the last 2,000 years.

Related Articles


The findings come from a comprehensive geochemical analysis of sediment samples taken from Farewell Lake in a remote, environmentally sensitive area of Alaska. The work provides the first continuous record of temperature change spanning the last two millennia from that region, they write in the Aug. 21 issue of the Proceedings of the National Academy of Sciences.

"Naturally, the big question is whether human activity is causing the current warming," said principal investigator Feng Sheng Hu, a professor of plant biology and geology at the University of Illinois. "This study, however, doesn’t provide us with the analytical confidence to answer that directly. We can say that two apparently naturally occurring warm periods existed previously.

"This type of studies offer baseline information on natural climatic variability that will allow us to pursue a variety of climate-related questions,"he said. The study provides a snapshot of 2,000 years of growing seasons. Researchers analyzed lime deposits in the lake samples for their oxygen and carbon isotopic composition as well as trace-element contents. Such material is ideal for geochemical analysis and environmental reconstruction, Hu said.

The researchers concluded that warm climatic conditions occurred in A.D. 0-300 and 850-1200. During these periods, overall conditions were drier than the colder periods, they found. The initial warm period matches documented conditions in Northern Europe and wet weather in the American Southwest. The second warm period corresponds to a period known as the Medieval Climatic Anomaly.

A period of cold, reaching a peak in about A.D. 600, possibly contributed to the demise of the Kachemak culture in the northwestern Gulf of Alaska. A prolonged period of dry weather occurred in the American Southwest at this time.

In a follow-up study, Hu and postdoctoral associate Willy Tinner have found, based on preliminary data, a counter-intuitive discovery. They found that forest fires were more abundant during the colder conditions of the Little Ice Age (1400 to 1700). Such a finding is contradictory to many global warming predictions. Tinner presented the finding at the annual meeting of the Ecological Society of America in August.

The co-authors of the PNAS study are Hu, Emi Ito (University of Minnesota), Thomas Brown (Lawrence Livermore National Laboratory), Brandon Curry (Illinois State Geological Survey) and Daniel Engstrom (Minnesota Science Museum). The National Science Foundation funded the research.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Warmer Periods In Alaskan Area Not Confined To Modern Times." ScienceDaily. ScienceDaily, 21 August 2001. <www.sciencedaily.com/releases/2001/08/010821074720.htm>.
University Of Illinois At Urbana-Champaign. (2001, August 21). Warmer Periods In Alaskan Area Not Confined To Modern Times. ScienceDaily. Retrieved December 22, 2014 from www.sciencedaily.com/releases/2001/08/010821074720.htm
University Of Illinois At Urbana-Champaign. "Warmer Periods In Alaskan Area Not Confined To Modern Times." ScienceDaily. www.sciencedaily.com/releases/2001/08/010821074720.htm (accessed December 22, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Monday, December 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Lava Inches Closer to Highway

Raw: Lava Inches Closer to Highway

AP (Dec. 21, 2014) Officials have opened a new road on Hawaii's Big Island for drivers to take care of their daily needs if encroaching lava from Kilauea Volcano crosses a highway and cuts them off from the rest of the island. (Dec. 20) Video provided by AP
Powered by NewsLook.com
Raw: Scuba Diving Santa Off Florida Keys

Raw: Scuba Diving Santa Off Florida Keys

AP (Dec. 20, 2014) A scuba diving Santa Claus explored the waters of the Florida Keys National Marine Sanctuary. Dive shop owner Spencer Slate makes the dive each year to help raise money for charity. (Dec. 20) Video provided by AP
Powered by NewsLook.com
Obama: Better Ways to Create Jobs Than Keystone Pipeline

Obama: Better Ways to Create Jobs Than Keystone Pipeline

AFP (Dec. 19, 2014) US President Barack Obama says that construction of the Keystone pipeline would have 'very little impact' on US gas prices and believes there are 'more direct ways' to create construction jobs. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Lava on Track to Hit Hawaii Market

Raw: Lava on Track to Hit Hawaii Market

AP (Dec. 19, 2014) Lava from an active volcano on Hawaii's Big Island slowed slightly but stayed on track to hit a shopping center in the small town of Pahoa. (Dec. 19) Video provided by AP
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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