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 27, 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.

Related Articles


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.


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, 27 June 2000. <www.sciencedaily.com/releases/2000/06/000625233031.htm>.
National Science Foundation. (2000, June 27). Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2000/06/000625233031.htm
National Science Foundation. "Discovery Of Fossil Mollusks In Alaska Links Histories Of Arctic Ocean And Isthmus Of Panama." ScienceDaily. www.sciencedaily.com/releases/2000/06/000625233031.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
3D Map of Antarctic Sea Ice to Shed Light on Climate Change

3D Map of Antarctic Sea Ice to Shed Light on Climate Change

Reuters - Innovations Video Online (Nov. 24, 2014) A multinational group of scientists have released the first ever detailed, high-resolution 3-D maps of Antarctic sea ice. Using an underwater robot equipped with sonar, the researchers mapped the underside of a massive area of sea ice to gauge the impact of climate change. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Ruins Thought To Be Port Actually Buried Greek City

Ruins Thought To Be Port Actually Buried Greek City

Newsy (Nov. 24, 2014) Media is calling it an "underwater Pompeii." Researchers have found ruins off the coast of Delos. 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:

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