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:4/24/2017)... 2017 Janice Kephart , former ... Strategy Partners, LLP (IdSP) , today issues the ... Trump,s March 6, 2017 Executive Order: Protecting ... can be instilled with greater confidence, enabling the ... refugee applications are suspended by until at least ...
(Date:4/17/2017)... MELBOURNE, Florida , April 17, 2017 ... security technology company, announces the filing of its 2016 Annual Report ... Securities and Exchange Commission. ... Report on Form 10-K is available in the Investor Relations section ... well as on the SEC,s website at http://www.sec.gov . ...
(Date:4/11/2017)... PALM BEACH GARDENS, Fla. , April 11, ... biometric identity management and secure authentication solutions, today ... million contract by Intelligence Advanced Research Projects Activity ... technologies for IARPA,s Thor program. "Innovation ... the onset and IARPA,s Thor program will allow ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased ... of over 5.5 million people each year. Especially those living in larger cities are ... - based in one of the most pollution-affected countries globally - decided to take ...
(Date:10/10/2017)... PA (PRWEB) , ... October 10, 2017 , ... ... City Science Center’s FirstHand program has won a US2020 STEM Mentoring Award. Representatives ... the award for Excellence in Volunteer Experience from US2020. , US2020’s mission is ...
(Date:10/10/2017)... ... October 10, 2017 , ... The Pittcon Program Committee ... honoring scientists who have made outstanding contributions to analytical chemistry and applied ... the world’s leading conference and exposition for laboratory science, which will be held ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... October 5, 2017, in the medical journal, Epilepsia, Brain Sentinel’s SPEAC® System ... standard, video EEG, in detecting generalized tonic-clonic seizures (GTCS) using surface electromyography ...
Breaking Biology Technology:
Cached News: