650 Years of Sea Ice ChangeAlmost 650 years of annual change in sea-ice cover can been seen in
the calcite crust growing among layers of seafloor algae, says a new
study from the University of Toronto Mississauga (UTM). With colleagues from the Smithsonian Institution, Germany and Newfoundland, Halfar collected and analyzed samples of the alga Clathromorphum compactum. This long-lived plant species forms thick rock-like calcite crusts on the seafloor in shallow waters 15 to 17 metres deep. It is widely distributed in the Arctic and sub-Arctic Oceans. Divers retrieved the specimens from near-freezing seawater during
several research cruises led by Walter Adey from the Smithsonian. This continuous cycle of dormancy and growth results in visible layers that can be used to determine the length of time the algae were able to grow each year during the ice-free season. Coral ecosystem courtesy NOAA. Read more at ScienceDaily. 2013©. Copyright Environmental News Network |