Featured Research

from universities, journals, and other organizations

From Greenhouse To Ice House: Important Role Of The Indonesian Gateway Suggested

Date:
May 19, 2009
Source:
Leibniz Institute of Marine Sciences (IFM-GEOMAR)
Summary:
One of the mysteries of the Earth's history is the fundamental climate change in the Mid Pliocene, about 3.5-2.5 million years ago. By that time warm climate conditions ended and the ice caps in the northern hemisphere developed. Investigations by marines scientists suggest that changes in the Indonesian throughflow might have been the determining process for this fundamental climate change.

Schematic pattern of sea (sub)surface currents for today and 5 Ma in the Indonesian Throughflow (ITF) area. The 5 Ma scenario is based on general circulation models. Note that the source of water masses entering the Indian Ocean changed considerably.
Credit: Copyright IFM-GEOMAR

One of the mysteries of the Earth’s history is the fundamental climate change in the Mid Pliocene, about 3.5-2.5 million years ago. By that time warm climate conditions ended and the ice caps in the northern hemisphere developed. Investigations by marines scientists from Germany and India suggest that changes in the Indonesian throughflow might have been the determining process for this fundamental climate change.

Related Articles


The forcing mechanisms initiating the Mid-Pliocene climate change from a „Greenhouse“ to an „Icehouse World“ with extended continental ice sheets at high northern latitudes is still controversely debated – although quite sophisticated geochemical methods are at hand to reconstruct Earthดs history. There are notions that the closure of the Panamanian Gateway was pre-conditioning high northern latitude glaciation. Now, a group of marine scientists from Germany and India under the leadership of the Leibniz Institute of Marine Sciences (IFM-GEOMAR), Kiel, found compelling evidence that between 3.5-2.5 million years the watermass throughflow of the Indonesian Gateway changed at the subsurface level from warm and saline South Pacific watermasses towards cool and fresh ones originating from the North Pacific – with dramatic climatic effects.

Their findings are supported by model results suggesting that the continuous plate tectonic narrowing of the Indonesian Seaway might have had an ever-lasting impact on global climate change. The importance of the Indonesian Gateway is apparent as it is at a key location of the global thermohaline circulation, linking two major ocean basins and transferring huge amounts of heat from the Pacific into the Indian Ocean.

Indeed, the Mid-Pliocene change in the Indonesian throughflow induced not only a dramatic cooling of ca. 4ฐC in the tropical Indian Ocean subsurface level (ca. 300-400m), but also contributed to a significant ocean surface cooling in various upwelling regions worldwide, said Cyrus Karas, first author of the study.

The dramatic subsurface cooling signal was most likely transported westward into the Indian Ocean and further towards the South Atlantic via the Agulhas Current. Upwelling processes off South West Africa and off Somalia, might have brought the cold signal to the surface. Colder sea surface temperatures in the West Indian Ocean might have led to less evaporation, dryer conditions in East Africa and in consequence, to a change in hominid evolution.

Even the equatorial East Pacific, where today cold upwelling appears, might have been affected through the constriction of the Indonesian Gateway. With the change in Indonesian subsurface throughflow, the authors suspect that an increasing portion of cold Subantarctic Mode Water was transported via „ocean tunnels“ northward and contributed to the Equatorial Undercurrent. This subsurface current might have transported the cold water signal all the way from the West to the East Pacific not only amplifying the cold upwelling there, but also terminating the permanent El Ni๑o-like state of the Pliocene world.


Story Source:

The above story is based on materials provided by Leibniz Institute of Marine Sciences (IFM-GEOMAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Karas et al. Mid-Pliocene climate change amplified by a switch in Indonesian subsurface throughflow. Nature Geoscience, May 18, 2009; DOI: 10.1038/ngeo520

Cite This Page:

Leibniz Institute of Marine Sciences (IFM-GEOMAR). "From Greenhouse To Ice House: Important Role Of The Indonesian Gateway Suggested." ScienceDaily. ScienceDaily, 19 May 2009. <www.sciencedaily.com/releases/2009/05/090518102954.htm>.
Leibniz Institute of Marine Sciences (IFM-GEOMAR). (2009, May 19). From Greenhouse To Ice House: Important Role Of The Indonesian Gateway Suggested. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2009/05/090518102954.htm
Leibniz Institute of Marine Sciences (IFM-GEOMAR). "From Greenhouse To Ice House: Important Role Of The Indonesian Gateway Suggested." ScienceDaily. www.sciencedaily.com/releases/2009/05/090518102954.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) — Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) — Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Antarctic Sea Ice Mystery Thickens... Literally

Antarctic Sea Ice Mystery Thickens... Literally

Newsy (Nov. 25, 2014) — Antarctic sea ice isn't only expanding, it's thicker than previously thought, and scientists aren't sure exactly why. Video provided by Newsy
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

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