HOME >> BIOLOGY >> NEWS
Tropical glaciers formed while earth was giant snowball

Boston, Mass. Glacial deposits that formed on tropical land areas during snowball Earth episodes around 600 million years ago, lead to questions about how the glaciers that left the deposits were created. Now, Penn State geoscientists believe that these glaciers could only have formed after the Earth's oceans were entirely covered by thick sea ice.

"There is strong geologic evidence of tropical glaciation at sea level during those times," Dr. David Pollard, research associate, Penn State College of Earth and Mineral Sciences' Environmental Institute, told attendees at the spring meeting of the American Geophysical Union today (May 29) in Boston. "We wanted to determine how low-level tropical glaciers could have formed."

Ice can accumulate in the tropics only if temperatures are below freezing or around freezing with large amounts of snowfall. Tropical glaciers exist today only on high mountain peaks such as the Andes and Mt. Kilimanjaro, and do not reach anywhere near sea level. Pollard and James K. Kasting, professor of geosciences, first looked at the possibility that tropical ice sheets formed before the oceans completely froze into a snowball Earth, when equatorial oceans were still ice-free and could supply enough moisture for substantial snowfall.

During the lead-up to a snowball Earth episode, the Earth gradually cools because the amount of carbon dioxide in the Earth's atmosphere decreases. Relatively fast weathering of silicate rocks on large tropical landmasses causes this decrease that locks up carbon. As the earth cools, the oceans begin freezing. The high reflectivity of the snow and ice that covers the northern and southern oceans, reflects, rather than absorbs, the sun's heat and further cools the planet. This cooling takes place slowly until the oceans are frozen to about 30 degrees latitude, or from the North Pole down to New Orleans, La. and from the South Pole up to the tip of South Africa.

"This is the
'"/>

Contact: A'ndrea Elyse Messer
aem1@psu.edu
814-865-9481
Penn State
31-May-2001


Page: 1 2 3

Related biology news :

1. Tropical legume could be alternative hay/forage crop for Texas
2. Tropical deforestation and global warming
3. Arthropods of Tropical Forests
4. Tropical Science for the 21st Century
5. A Magic Web: The Tropical Forest of Barro Colorado
6. Ira Rubinoff honored by the Association for Tropical Biology
7. Tropical forests under surveillance
8. Tropical scientists find fewer species than expected
9. Sessions on bioterrorism featured at Tropical Medicine Meeting
10. Chemistry in the Amazon: Tropical birds, Amazonian tribespeople derive medicinal benefits from insects, plants
11. Tropical tree distribution could have implications for forest management, conservation

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:12/2/2016)... Dec. 1, 2016   SoftServe , a ... BioLock , an electrocardiogram (ECG) biosensor analysis system ... key IoT asset. The smart system ensures device-to-device ... steering wheel and mobile devices to easily ,recognize, ... As vehicle technology advances, so too must ...
(Date:11/29/2016)... , Nov. 29, 2016   ... identification and object recognition technologies, today released ... for fingerprint recognition solutions that run on ... fingerprint template using less than 128KB of ... compact devices that have limited on-board resources, ...
(Date:11/22/2016)... 22, 2016 According to the new market research ... Face, Vein, Signature, Voice), Multi-Factor), Component (Hardware and Software), Function (Contact and ... the market is expected to grow from USD 10.74 Billion in 2015 ... between 2016 and 2022. Continue Reading ... ...
Breaking Biology News(10 mins):
(Date:12/9/2016)... 2016 The research report by ... in the  Global Label-Free Array Systems Market  accounted for ... 2015. Players such as Biacore, Agilent Technologies, ForteBio, Molecular ... the global market due to their unmatched product portfolio ... upgrades and timely product launches are expected to be ...
(Date:12/8/2016)... -- The Board of Directors of the Pittsburgh Life ... only pure life sciences investment firm, today announced ... plan developed by the Nominating and Governance Committee over ... F. Jordan is selected to serve as President ... , who is elected to the position of Executive ...
(Date:12/8/2016)... , December 8, 2016 AskLinkerReports.com ... comprehensive analysis, titled Global Amyloglucosidase Industry 2016 Market Research Report. ... application, and industry chain overview are all covered in the ... analysis, and investment return analysis of the Amyloglucosidase industry. ... , , ...
(Date:12/8/2016)... Oregon (PRWEB) , ... December 08, 2016 , ... ... and the FrontPanel SDK that provide essential device-to-computer interconnect using USB or PCI ... not require FrontPanel support. The FOMD-ACV-A4 is a small, thin, SODIMM-style module that ...
Breaking Biology Technology:
Cached News: