Slow Days and Bad Weather, and The Promise of Better

February 8th 2010

Sometimes you get to core, sometimes you do not.

The last two days, we have not.  We finished at the Adelie Drift site, and headed along the coast to get to our next drillsite.  While we were doing this, we dropped below the Antarctic Circle for a bit! 

Now the Antarctic Circle, and its northern hemisphere relative, the Arctic Circle, are about 66.33 degrees South or North of the equator.  If you are past these lines, then there is at least one day a year where the sun never sets during summer, and at least one day a year where the sun never rises during winter.

This is because of the tilt of the Earth’s axis.  The earth’s axis is not straight up and down, but tilted.  It is this tilt that gives us our seasons, during our winter in Michigan, the Northern Hemisphere is tilted away from the sun, and the Southern Hemisphere is tilted towards the sun.  That means our winter in Michigan is summer in the Southern Hemisphere. 

It is a common mistake to think we are closer to the sun during the summer.  However, we actually are not any closer to the sun during the summer, it is that this tilt makes the suns rays more direct.  It is the same reason why summer days are so long, while winter days are so short, and why it so much easier to get a sunburn in the summer!

So these Antarctic and Arctic Circles are cool, but we were on our way to our next drillsite, so we could not stop.  But we could take photos!  This is the photo of the scientists and techs that were awake when we crossed the Circle, including me!

This drillsite is probably the most important place we are going on this trip, because it is here that we hope to recover the sediments deposited when Antarctica froze.  Back when dinosaurs ruled the Earth, Antarctica was a warm and wet place.  The Earth warmed up even more just after the dinosaurs died off until we reached something called the “Eocene Climatic Optimum”, when global temperatures on earth were as warm as we have any record of them being. 

After the Eocene Climatic Optimum (ECO), the planet started to cool down.  While it was slowly cooling for a while, something happened 33.7 million years ago, and the planet suddenly cooled very quickly.  This something was the building of very large ice sheets on Antarctica.  These ice sheets were probably similar to what we see today.  And the climate of the planet shifted.  And did so very fast geologically, though this change was still far slower then we are changing the climate now!

So scientists have found evidence of this shift from all over the world.  It is always at 33.7 million years ago, and it is always a major, major event.  But the one place we don’t have a good record is from Antarctica.  This is because of how hard it is to work in Antarctica, and the fact that the glaciers that are on Antarctica have done a very good job of destroying the evidence on land.

But when something is destroyed on land, it is almost always deposited in the oceans.  This is why we are here.  To see if we can find these sediments that were carried off of Antarctica by these first ice sheets.

We have tried to make it to this site already once.  In fact it was going to be our first stop!  That is how important it is!  But when we first got there, too many icebergs were in the way to make it safe for us to work.  So we went to the deep water site I talked about before.

After the Adelie drift, we headed back towards that site again.  And this time sailed right past it.  While it was a sunny, clear, and warm day, the weather report said we would be in for a big storm the next day, and there were still too many icebergs for us to work safely.  Even more because of the storm!  The storms winds would be nearly hurricane strength! Almost 70 miles per hour!

So we sailed past our most important site. . . again, and headed out into slightly deeper waters.  We hoped to get cores here from a major climate change in Antarctica during the middle Miocene.  This happened about 14 million years ago, and is another one of those ‘changes on Antarctica that change the world’ events.  Not quite as dramatic as the first ice sheets, but a big event!

Well, we stopped, got setup, tripped down the drillbit and started drilling.  But then an iceberg come towards us to say “hi”.  Now, we can not let icebergs get to close because they are clumsy and might bump into us, so we had to pull up and let it go by.

Then we tried again, and got about 30 meters of core when the bottom of the drillstring broke!  We have spares, but remember how long it takes to pull up and change something like that?

And with the storm bearing down on us, it was decided to head to deeper waters still and go to the other site we still have to drill.  Give the storms a few days to pass and head back.

All in all, it has been an annoying couple of days.  And sorry to all you Lambchop fans, I think I have posted enough text today, so I will let Lambchop explain the next step in the cores trip next time.

See you next time.