T258 The Tonian-Cryogenian World

Tuesday, 21 October 2014
1:00 PM - 5:00 PM
220

COULD PHOTOSYNTHETIC EUKARYOTES HAVE SURVIVED IN NEARLY ENCLOSED SEAS DURING THE SNOWBALL EARTH EVENTS?

Paper number: T258-15
Program: Technical Sessions
Time: 4:15 PM – 4:30 PM

Authors

Abstract

During the global glaciations of the Cryogenian, the Earth’s oceans may have been completely covered with ice. If thick ice globally covered the oceans, consistent with a “hard snowball” interpretation, then where photosynthetic eukaryotic organisms may have survived during global glaciations of the Cyrogenian remains unclear. Our research tests weather a narrow arm of the ocean, analogous to the modern Red Sea, could have been a refugium for photosynthetic eukaryotes during Snowball Earth events. We demonstrate that for a limited range of climate conditions, ice flow into an arm of the sea is restricted sufficiently to allow for the sea to remain partially free from sea-glacier penetration, a necessary condition for it to act as a refugium for photosynthetic eukaryotes during a Snowball Earth event. The range of possible climate conditions that allow for these nearly enclosed sea act as refugia for photosynthetic eukaryotes during is increased by considering the effect of a narrow entrance to the channel and the formation of ice shadows on the leeward side of obstacles within the channel.