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:
TAG: Tropical glaciers formed while earth was giant snowball

(Date:10/16/2014)... can be cultivated efficiently, they are anything but ... by monoculture cultivation is becoming increasingly evident. Despite ... form and are regarded as the sole possibility ... quite wrongfully, finds Bernhard Schmid, an ecology professor ... novel form of agriculture and forestry. After all, ...
(Date:10/15/2014)... our ability to assess the pandemic risk from strains ... we must not allow ourselves to become complacent that ... international consortium of scientists. , Influenza pandemics arise when ... yet to develop widespread immunity – spreads in the ... the past 100 years, the worst of which – ...
(Date:10/15/2014)... NXT-ID, Inc. (NASDAQ: NXTD and NXTDW) ... growing mobile commerce market releases photos and video of the recent ... October 13 th . Gino Pereira , ... angel investor Mr. Chad A. Verdi rang the bell.  ... his investors and employees "for their work and dedication in bringing ...
Breaking Biology News(10 mins):Plant communities produce greater yield than monocultures 2Plant communities produce greater yield than monocultures 3Scientists 'must not become complacent' when assessing pandemic threat from flu viruses 2Photo Release: NXT-ID Inc. Rings Opening Bell of the NASDAQ Stock Market October 13th 2Photo Release: NXT-ID Inc. Rings Opening Bell of the NASDAQ Stock Market October 13th 3
(Date:10/20/2014)... 20, 2014 PureTech , a science ... healthcare problems, announced today the closing of a ... from Invesco Perpetual, a $120 Billion group of ... PureTech,s existing pipeline forward and to advance new ... scientific creativity to really go for the big ...
(Date:10/19/2014)... 2014 The Latin American hardware encryption ... Latin America with analysis and forecast of revenue. This ... is expected to reach $2,366.8 million by 2018, at ... Browse through the TOC of the Latin American hardware ... in-depth analysis provided. It also provides a glimpse of ...
(Date:10/19/2014)... The Asian Automatic patient billing report defines and ... of revenue. The Automatic patient billing market in Asia ... 2018, at a developing CAGR of 7.2% from 2013 ... Asian Automatic patient billing market, to get an idea ... glimpse of the segmentation of this market in the ...
(Date:10/19/2014)... 2014 The report "Unmanned Ground ... Security), Technology, Payload, Type & by Geography - ... global unmanned ground vehicle market into various sub ... market sizes. The report also identifies the factors ... it along with the adoption trends. , The ...
Breaking Biology Technology:PureTech Announces Expansion with Oversubscribed $55M Funding Round 2PureTech Announces Expansion with Oversubscribed $55M Funding Round 3PureTech Announces Expansion with Oversubscribed $55M Funding Round 4PureTech Announces Expansion with Oversubscribed $55M Funding Round 5PureTech Announces Expansion with Oversubscribed $55M Funding Round 6The Latin American hardware encryption display market is expected to reach $2,366.8 million by 2018 - New Report by MicroMarket Monitor 2The Latin American hardware encryption display market is expected to reach $2,366.8 million by 2018 - New Report by MicroMarket Monitor 3The Asian Automatic patient billing market is estimated to grow to around $463.9 million by 2018 - New Report by MicroMarket Monitor 2The Asian Automatic patient billing market is estimated to grow to around $463.9 million by 2018 - New Report by MicroMarket Monitor 3Unmanned Ground Vehicle (UGV) Market Estimated to Reach $8.26 Billion by 2020 - New Research Report by MarketsandMarkets 2Unmanned Ground Vehicle (UGV) Market Estimated to Reach $8.26 Billion by 2020 - New Research Report by MarketsandMarkets 3Unmanned Ground Vehicle (UGV) Market Estimated to Reach $8.26 Billion by 2020 - New Research Report by MarketsandMarkets 4Unmanned Ground Vehicle (UGV) Market Estimated to Reach $8.26 Billion by 2020 - New Research Report by MarketsandMarkets 5
Cached News: