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:8/1/2018)... Ariz. (PRWEB) , ... July 31, 2018 , ... ... Father of Stevia Awards at Global Conference , Awards honor late founder of ... president of Wisdom National Brands, presented prestigious stevia awards to a renowned German ...
(Date:7/31/2018)... ... July 31, 2018 , ... ACEA Biosciences, is a privately owned biotechnology ... just introduced the xCELLigence RTCA S16, which the ideal entry level model for exploratory ... the S16can be placed in any standard CO2 tissue culture incubator. The user ...
(Date:7/31/2018)... ... , ... Fiberstar, Inc. , a global leader of clean label, functional ... years, Fiberstar added capacity, introduced new Citri-Fi® products and entered into new categories. To ... up with Batory Foods. , “Batory Foods has an excellent track record within ...
Breaking Biology News(10 mins):
(Date:7/25/2018)... ... 2018 , ... John McDonald, CEO of ClearObject , ... India Business Council (IIBC), an advocacy group to strengthen economic ties between Indiana ... McDonald joins an impressive roster of local and national business leaders from organizations ...
(Date:7/24/2018)... ... July 24, 2018 , ... R3 Stem Cell is now offering regenerative therapies ... offered by Double Board Certified providers, with outcomes significantly improving patient quality of life. ... have done nothing to help repair and regenerate damaged lung tissues. Stem cell ...
(Date:7/24/2018)... ... July 24, 2018 , ... ... of their highly successful SmartTRAK platform. Not just a pretty face, SmartTRAK ... and speed. , SmartTRAK is the world’s first online and real-time data ...
(Date:7/22/2018)... ... , ... Mitotech S.A, a Luxembourg based clinical stage biotechnology ... program in Dry Eye Disease. Under the agreement Essex Bio-Investment will fund U.S. ... first Phase 3 study starting as early as Fall 2018. , “We ...
Breaking Biology Technology:
Cached News: