Featured Research

from universities, journals, and other organizations

Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama

Date:
June 12, 2000
Source:
National Science Foundation
Summary:
Finding two fossil mollusks in a California collection led a researcher funded by the National Science Foundation (NSF) to undertake field work in Alaska that he says links the formation of the Isthmus of Panama approximately 3.6 million years ago to a reversal of water flow through the Bering Strait.

Finding two fossil mollusks in a California collection led a researcher funded by the National Science Foundation (NSF) to undertake field work in Alaska that he says links the formation of the Isthmus of Panama approximately 3.6 million years ago to a reversal of water flow through the Bering Strait.

Louie Marincovich, of the California Academy of Sciences, is the first to produce fossil evidence that the flow of water through the strait, which separates Russia and Alaska, was reversed from southward to northward by the uplifting of the Isthmus. He also is the first to date the flow shift.

Marincovich's findings also validate computer models of Northern Hemisphere oceanography for that time period, at least as they affected the Arctic Ocean.

"This discovery was only possible because someone picked up two fossils in Alaska in the 1970's, not knowing what they were and donated them to the California Academy of Sciences, where I recognized them 25 years later," Marincovich said. "I was going through the collections with another topic in mind when I saw them and had my 'Eureka moment,' when I knew they were the first datable evidence of the Bering Strait's being open."

Astarte, the fossil mollusk, lived only in the Arctic and North Atlantic oceans until prior to the opening of the strait.

The discovery of an Astarte in southern Alaska in rocks almost 5.5 million years old led Marincovich to conclude that the Bering Strait must have first opened at that time. In order to be found in southern Alaska, Astarte must have migrated southward through Bering Strait.

What was puzzling about his find is that nearly two million years passed before mollusks from the Pacific began migrating northward through the open Bering Strait to the Arctic and North Atlantic oceans. Pacific mollusks first appear in the fossil record there only 3.6 million years ago.

Marincovich's research on fossil mollusks in the North Pacific, Arctic and North Atlantic oceans led him to conclude that the direction of seawater flow through the Bering Strait gateway must have changed from a southerly flow to a northerly one around 3.6 million years ago. This reversal in flow direction had been theorized by computer models of past ocean flow, and was thought to have been caused by formation of the Isthmus of Panama as a land barrier where a broad tropical seaway between North and South America had existed for millions of years.

The formation of this tropical isthmus caused drastic shifts in Northern Hemisphere ocean currents, and initiated the flow of the Gulf Stream. However, just when these changes took place and affected the Arctic Ocean was a mystery not predicted by the computer models.

Marincovich's work was funded by the Arctic natural sciences section of NSF's Office of Polar Programs. An article about his findings may be found in the June issue of Geology, a publication of the Geological Society of America.

Editors: For a PDF file of the research article, see: ftp://204.144.241.6/pub/geology/28-551.pdf.


Story Source:

The above story is based on materials provided by National Science Foundation. Note: Materials may be edited for content and length.


Cite This Page:

National Science Foundation. "Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama." ScienceDaily. ScienceDaily, 12 June 2000. <www.sciencedaily.com/releases/2000/06/000612085120.htm>.
National Science Foundation. (2000, June 12). Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2000/06/000612085120.htm
National Science Foundation. "Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama." ScienceDaily. www.sciencedaily.com/releases/2000/06/000612085120.htm (accessed July 22, 2014).

Share This




More Fossils & Ruins News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Neil Armstrong's Post-Apollo 11 Life

Neil Armstrong's Post-Apollo 11 Life

Newsy (July 19, 2014) — Neil Armstrong gained international fame after becoming the first man to walk on the moon in 1969. But what was his life like after the historic trip? Video provided by Newsy
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) — As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Tooth Plaque Provides Insight Into Diets Of Ancient People

Tooth Plaque Provides Insight Into Diets Of Ancient People

Newsy (July 19, 2014) — Research on plaque from ancient teeth shows that our prehistoric ancestor's had a detailed understanding of plants long before developing agriculture. Video provided by Newsy
Powered by NewsLook.com
45 Years Later, Buzz Aldrin on Walking on Moon

45 Years Later, Buzz Aldrin on Walking on Moon

AP (July 18, 2014) — Forty-five years ago Sunday, Apollo 11's Neil Armstrong and Buzz Aldrin became the first humans to set foot on the moon. Speaking at the Intrepid Sea, Air & Space Museum, Aldrin described what he was thinking right before the historic walk. (July 18) 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:
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