This blog provides commentary on interesting geological events occurring around the world in the context of my own work. This work is, broadly, geological fluid dynamics. The events that I highlight here are those that resonate with my professional life and ideas, and my goal is to interpret them in the context of ideas I've developed in my research. The blog does not represent any particular research agenda. It is written on a personal basis and does not seek to represent the University of Illinois, where I am a professor of geology and physics. Enjoy Geology in Motion! I would be glad to be alerted to geologic events of interest to post here! I hope that this blog can provide current event materials that will make geology come alive.

Banner image is by Ludie Cochrane..

Susan Kieffer can be contacted at s1kieffer at gmail.com

Monday, December 30, 2013

Australian icebreaker nearing Akademik Shokalskiy ship in Antarctica

View from the Akademik Shokalsky a day ago
from the NYTimes.com 
Nearly a week ago, the Russian ship, Akademik Shokalskiy ship became trapped in ice in the Antarctic. The ship is an ice-strengthened expedition vessel, currently carrying both tourists and scientists studying environmental change near Cape de la Motte, about 1,700 miles south of Hobart, Tasmania. Strong winds pushed the ice pack against the ship, with ice thicknesses around 10 m. Earlier a Chinese vessel, the Xue Long attempted the rescue, but was frustrated by thick ice over the weekend.
The Russian icebreaker Krasin leading
an American supply ship into McMurdo Station
from Wiki here.
     Now, the Australian icebreaker, the Aurora Australis, is only 11 nautical miles from the ship and nearing a rescue. At the moment, the link above shows the view from the ships webcam! So, how do icebreakers work? The primary job of the icebreaker is to crush the icpack and move it aside whiteout becoming stuck itself. According to Marshall Brain on "How Stuff Works", an icebreaker has characteristics that help it do this: (1) a high-strength hull; (2) a large mass to help it maintain momentum so that it doesn't get stuck itself; and (3) power to overcome the drag of the crushed ice. Must be a noisy place!
     Here's a bit more from Wiki: The icebreakers push straight into the ice, breaking up the ice, sometimes even driving its bow onto the ice surface so that the weight of the ship helps break up the ice. The design of the hull is such that the broken ice is then directed around or under the vessel. The design is also optimized to minimize damage to the propellers and other parts of the icebreaker itself. Icebreakers have variously been steam-powered, diesel -powered, and nuclear-powered. They have been designed to function on rivers (e.g., in Europe) as well as on the open ocean. The photo shown next is of a successful rescue.

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