From Mindy, dated 17 January:
Rough days at sea ahead as we go back through the Drake Passage. I shouldn't complain, because we are actually experiencing rather calm conditions for this notoriously violent section of ocean. As we get our daily wake up call from Ted Cheeseman (who has such a calming and optimistic voice that it makes you excited about the day as soon as you hear him) (what else would you expect from a guy named "Cheeseman"? - Ed.), we have a thick fog and the ship is navigating by radar. The water temperature is 1.5 degrees C, air is 3 C, barometer at 994, and there is negligible winds with 1-2 meter swells.
If you read the blog post for Jan 8, you might remember that we had some rough seas going through Drake passage the first time. Well, last night we found out that a whopper of a storm came in right behind us that day. Sometime shortly after there was another cruise ship of similar size taking the same route... They got caught in the monster storm, and the windows were blown out on the bridge (several people were injured by shards of glass, and the ship returned immediately to Ushuaia, canceling that cruise and the next scheduled cruise for that ship)! With that shocking story, we were all reminded of the luck we are having with weather, and I have nothing to complain about with today's ship jostling (I have at least been able to function for a majority of the day, although with somewhat of a green face).
We had several lectures throughout the day from our geology and ecology expedition leaders. I missed several of them because it is very easy to get queasy in the lecture room (it is on the bottom deck and right at the center of the ship with no windows). Pauline Carr shared stories of ocean explorers in a lecture called "Terra Becomes Cognita: the Heroic Age Explorers." Ian Dalziel spoke more about the geologic history in the region, summing up "Antarctica and Supercontinental Evolution." Rob Dunbar gave a talk on "Climate Change in Antarctica: Stories from Sediment Cores." Michael Moore gave a very insightful talk on "Penguins, Whales, and Climate Change." Finally, Richard Alley spoke about "How Glaciers use Earthquakes to Make Beautiful Scenery." (Californians, take note - Ed.)
I only mustered enough energy to make it to Richard's talk (although I had to lie on the floor to calm my stomach), but I learned some unexpected things about glacial weathering... one of them being that glaciers can modify landforms quicker than rivers (but sometimes they don't). The Taku glacier in Alaska has been measured at 3 meters/year erosion rates, and the Riggs glacier, also in Alaska was measured at 30 meters per year sedimentation rates in front of the glacier! If you think about the Antarctic continent, and you just assume a 1 cm/yr erosion rate (the common average of all glaciers measured) the whole continent should be gone under the Antarctic ice sheets (and in fact the ice would have worn down to the earth's mantle by now), so something is moderating the potential behavior of the Antarctic ice sheets so that they are not eroding like other ice sheets. To stop a glacier from transforming the landscape underneath it, you can either have it frozen solid onto the bedrock, or have a thawed bed but no meltwater. Earthquakes can then play a significant role in shaping the landforms because they essentially allow hydro-fracking in the cracks in rocks (this explains how you have sharp "cliff-like" edges in glacial geomorphology (otherwise, the ice would have rounded everything and polished it much like river cobbles over the years). (Got all that? - Ed.)
Several folks on the trip completed a final drawing workshop with Edward Rooks to work on their pieces of art from the trip. Everyone feverishly edited and organized their photos (with the help of professional photographers Tom Murphy and Scott Davis) so that we could collect the best ones for a group slide show. We also turned in items for an auction to be held on the last day of the trip, raising money for a rat eradication project on South Georgia Island. More on that exciting tidbit tomorrow.
Late in the evening there was a screening of a movie called "Around Cape Horn" which was made by Captain Irving Johnson in 1929 during the last great days of sailing. I could not stomach watching a movie that was shot with a hand-crank camera on rough seas (and shown in a notoriously risky room for getting sea sick). But, I heard rave reviews from everyone who saw it, and I will definitely track down this movie when I get home. (See link above - Ed.)
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| Enjoying the Southern Ocean (click to enlarge) |
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| Rough sea at sunset (Click to enlarge) |
We had several lectures throughout the day from our geology and ecology expedition leaders. I missed several of them because it is very easy to get queasy in the lecture room (it is on the bottom deck and right at the center of the ship with no windows). Pauline Carr shared stories of ocean explorers in a lecture called "Terra Becomes Cognita: the Heroic Age Explorers." Ian Dalziel spoke more about the geologic history in the region, summing up "Antarctica and Supercontinental Evolution." Rob Dunbar gave a talk on "Climate Change in Antarctica: Stories from Sediment Cores." Michael Moore gave a very insightful talk on "Penguins, Whales, and Climate Change." Finally, Richard Alley spoke about "How Glaciers use Earthquakes to Make Beautiful Scenery." (Californians, take note - Ed.)
I only mustered enough energy to make it to Richard's talk (although I had to lie on the floor to calm my stomach), but I learned some unexpected things about glacial weathering... one of them being that glaciers can modify landforms quicker than rivers (but sometimes they don't). The Taku glacier in Alaska has been measured at 3 meters/year erosion rates, and the Riggs glacier, also in Alaska was measured at 30 meters per year sedimentation rates in front of the glacier! If you think about the Antarctic continent, and you just assume a 1 cm/yr erosion rate (the common average of all glaciers measured) the whole continent should be gone under the Antarctic ice sheets (and in fact the ice would have worn down to the earth's mantle by now), so something is moderating the potential behavior of the Antarctic ice sheets so that they are not eroding like other ice sheets. To stop a glacier from transforming the landscape underneath it, you can either have it frozen solid onto the bedrock, or have a thawed bed but no meltwater. Earthquakes can then play a significant role in shaping the landforms because they essentially allow hydro-fracking in the cracks in rocks (this explains how you have sharp "cliff-like" edges in glacial geomorphology (otherwise, the ice would have rounded everything and polished it much like river cobbles over the years). (Got all that? - Ed.)
Several folks on the trip completed a final drawing workshop with Edward Rooks to work on their pieces of art from the trip. Everyone feverishly edited and organized their photos (with the help of professional photographers Tom Murphy and Scott Davis) so that we could collect the best ones for a group slide show. We also turned in items for an auction to be held on the last day of the trip, raising money for a rat eradication project on South Georgia Island. More on that exciting tidbit tomorrow.
Late in the evening there was a screening of a movie called "Around Cape Horn" which was made by Captain Irving Johnson in 1929 during the last great days of sailing. I could not stomach watching a movie that was shot with a hand-crank camera on rough seas (and shown in a notoriously risky room for getting sea sick). But, I heard rave reviews from everyone who saw it, and I will definitely track down this movie when I get home. (See link above - Ed.)
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