About this Blog

This blog is dedicated to a research expedition to the McMurdo Dry Valleys in Antarctica. Through field mapping of geomorphic evidence, sample collection, and cosmogenic nuclide concentration measurements in the Noble Gas Lab at Harvard, we hope to better understand the behavior of the East Antarctic Ice Sheet during Miocene (~23 to 5 million years ago) and Pliocene (~5-1.8 mya) times. The Early Pliocene is the most recent period in which global temperatures were significantly warmer than the present, therefore providing us with a potential analog for a warming climate. This research is generously funded by the NSF Polar Science Program.

Tuesday, December 23, 2008

It’s a Harsh Continent

Dec. 19th
Ahoy! Yesterday we took a trip down to Clark Valley (located east of our camp about a 25 minute helicopter ride, where the Lower Wright Glacier terminates out of the frozen McMurdo Sound), which is as close to a “day at the beach” as we’ll be getting down here. In Clark Valley, we took samples to investigate the possibility of the existence of a large lake during the last glacial maximum. We also frolicked amongst the assorted rock types as the geo-inclined are wont to do (here we came across glacial deposits from Ross Island and granite bedrock in addition to the sandstone and dolerite we’ve been seeing for the past two weeks). Unfortunately, (Allen and) I got schooled by both Robert and Rob when it came to identifying a few of the more mafic minerals and may or may not have been mocked about our geological shortcomings for the rest of the day.
Later in the afternoon, we hiked over to the longest river in Antarctica – the Onyx River (really just a large stream) and waited for our helicopter by its rocky banks. Weirdly, the Onyx flows inland “up” Wright Valley and ends in Lake Vanda (this is because the lowest elevation of the valley occurs in the middle, not at the end). In addition to transporting us back to camp, our helo also dropped off a few resupply boxes full of goodies like new mittens for me, oatmeal, and 7 pounds of beef jerky (please note that this ridiculously high quantity of jerky is due to a slight miscommunication and not to an insatiable desire for dehydrated meat, although there is that, too).
Today we hiked up to the headwall of our valley in the Olympus Range and scrambled up a few various crumbling sandstone slopes to take samples along the way. The most notable aspect of our day, however, was the increased velocity with which air particles attacked us and stole our heat. Not only could we hear the wind howl past our ears, and feel its force on our faces (and sides, and backs… it kept changing direction even when we were stationary), but we could see its might by watching snow from the polar plateau fly over the ridge into our valley and then whirl about in mini-vortexes before settling to the ground. Actually, we’ve been rather lucky to get as many calm moments as we have because strong winds are the norm out in the Dry Valleys. The existence of the glaciers fed almost entirely by windblown snow is a good testament to the frequency of windy days.

Dec. 20th
Today was yet another beautiful day in the Dry Valleys. I’ve started carrying a thermometer and it held steady at -5°C all day. As we keep saying to each other, it’s a harsh continent. (Just in case the sarcasm doesn’t transmit...that was sarcastic.) The wind calmed down a bit overnight and we awoke to an eerie, but appreciated, stillness around camp. Robert, Rob, and I spent most of the day collecting samples from boulders that have fallen from the steep cliffs of Electra’s east face. Hopefully, we may be able to date a few of the major rock falls that have occurred in the past several million years by sampling the right boulders. In addition to the insight this would give us into sandstone erosion in the Olympus range, this information would perhaps also quantify the statistical risk we undertook to stand under an eroding cliff face for hours on end banging on rocks.
In other news, Allen spent most of the day wandering back and forth across the terrain with the differential GPS on his back while listening to Harry Potter on audiobook. In theory he was logging data in order to make a topo map of the large sandstone basins in the area… but I think he’s finally cracked.

Dec. 21st
Happy Solstice! Unfortunately we couldn’t fully appreciate the longest day of the year down here due in part to the fact that the sun hasn’t set in weeks and in part to the thick cloud layer that prevented the sun’s warming rays from reaching us today. I suspect that those of you currently experiencing the darkest day of the year have little sympathy for us fools, though.
In tribute to the weekend, we took the day off from sampling and instead spent our time reading, doing homework, baking brownies, and staring at the book of stereo optical illusions/magic eye that the fabulously thoughtful Su Gao (another Harvard EPS undergraduate) sent down in a package. So thanks Su and everyone else who has taken the time to send mail all the way down to Antarctica, we fully appreciate it (and hopefully our outgoing mail will get to you before we return to the States/ New Zealand).

In the foreground in Clark Glacier, with a small glacier flowing
towards it, not quite joining up. More importantly, the peak on
the left is named Mount Allen.

Rob and Robert step out into Clark Valley.

Looking West onto McMurdo Sound, Lake Brownworth in front.

The mighty Onyx River.

Jenny on the north bank of the Onyx.

The headwall of our valley - those sandstone outcrops are about
300 ft tall.

Windblown snow off the ridge and glaciers below.

I’m glad I wasn’t there when this thing fell off of Electra.

Allen, in a useful moment, using the GPS.

1 comment:

Peter Hedman said...

Very amazing. The longest river in Antarctica, possibility of death by boulder, and swirling snow!

The Winter Solstice here...in Cleveland...Ohio...was very dark indeed and I am very jealous of your sunlight and desolate landscapes.