Northbound

It's been a busy week in McMurdo trying to get prepared to leave Antarctica tomorrow. My team and I have been busily cleaning and returning gear to the Berg Field Center and the Crary Lab.

The biggest task this week has been preparing samples to be shipped north. I've got all kinds of samples that all have different processing and transportation requirements. It's kind of like trying to figure out how to load a grocery bag. You want your ice cream to stay frozen, your apples not to get bruised, and your eggs not to crack. Only here, I need my ice cores (from Garwood) to stay frozen, my soils (from Taylor) not to grow mold, and my rocks (from everywhere) not to get chipped. Fortunately, the cargo vessel that will be docking in McMurdo next month has freezers, coolers, and giant storage containers aboard that should get my samples home safe and sound.

Since Antarctica is in the southern hemisphere, and Portland is in the northern hemisphere, the ship has to cross the equator to get my samples home. It's pretty impressive to think that the ship can keep ice cores at -20*C (-4*F), even when it's 90*F outside. Since my soils don't need to be in a freezer the whole way back, they need to be dried so that they don't grow mold in the heat (the same way foods like potato chips or raisins are dried to keep them from getting moldy).

I'd say it has been a great season. We've learned a lot about how the "invisible streams" in Taylor Valley (the water tracks) come out of their winter freeze. In Garwood, we've begun to explore a frozen world that existed almost 10,000 years ago. It's been an adventure at times:

Sampling algal mats at the top of the Garwood Valley "ice cliff." It might not seem  like much of an adventure, but to get there I had to cut toe holds in the ice...

...all the way up to the top of the wall here. It's worth it, though, since we can carbon date the algae in the sediments. The sediments are on top of the ice, so the ice has to be at least as old as the sediments that bury it (geologists call this "the law of superposition). Get an age for the algae, and we've got an age for the ice. 

It's also been a great deal of fun. My colleagues--both the scientists, and the support personnel--have been a pleasure to work with. I'm definitely ready to be heading home, but a little piece of me is already excited about continuing to explore in Garwood valley next year!

Stay tuned to this blog during the "off season" for updates on what we've found in the Dry Valleys, news about publications, and more stereo pictures!

Northbound tomorrow.

One last day in the field

I'm sitting in the Lake Hoare hut in the heart of Taylor Valley, waiting for a helicopter that will take me, Thomas Nylen (whose photos are in this post), and Jim O'Connor (a colleague from the US Geological Survey) down to the end of the valley for one last day of fieldwork. It definitely makes me sad to be leaving the field (and sadder to know that I have a solid week of labwork ahead of me--the same kinds of things I did earlier this season). But we couldn't ask for better weather, or a better last project.

We'll launch from Lake Hoare aboard an A-Star helicopter.

An A-Star helicopter dropping off a "sling load" (cargo attached to the helicopter by a cable).

A short flight down the valley, and we'll arrive at the New Harbor camp--a small hut and lab on the shore of the Ross Sea. I'm going to meet Ron Sletten, another permafrost geologist, to talk about a research borehole he's drilled into the soil here. Jim is going to look at more paleo-deltas from when the lakes of Taylor Valley were linked and flowed into the Ross Sea.

Then we'll walk inland to a spot called "Explorer's Cove." The LTER maintains a weather station there, where Thomas needs to do some maintenance work, and I need to collect one last soil sample. 

Then we'll continue our hike inland, past the Lake Fryxell camp, and then up and over the Canada glacier back to Lake Hoare. It should be a pretty excellent walk. Not a bad way to wrap up an Antarctic field season. 

Old Ice in Garwood Valley

I'm back from a week of tent camping in Garwood Valley--one of the southernmost Dry Valleys (more than 78 degrees South!). The mission was a great success. I'm starting a new project to study buried glaciers that flooded the valley more than 10,000 years ago. Unlike most glaciers from that era, which have long since melted, this ice is preserved under a thick sand cover.

Buried ice, to the right, in Garwood Valley. A 3 m tall weather station is next to the ice.

The ice is not stable, though. It formed under much colder conditions during the last glacial maximum and is now melting and sublimating away. It's particularly at risk of melting where the ice is exposed to the warm, dry summer atmosphere--so the "ice cliff" in the above photo is melting away like an ice cream cone on a hot afternoon. The melting of the buried ice, coupled with erosion by the Garwood river, means that this treasure trove of climate data from the recent past is quickly disintegrating.

A block of ice and sediment from the last glacial maximum that has tumbled from its perch into the Garwood river. Best not to be working on the cliff when one of these comes down.  

What we're trying to understand in Garwood is how thick was the ice in Antarctica 10,000 years ago and what was the climate like. This is important because Garwood is one of the few places in Antarctica that is currently undergoing rapid landscape change because of warm temperatures (relative to 10,000 years ago). It's like a crystal ball that we can use to look into the future of the Antarctic Dry Valleys to predict how the glaciers and permafrost soils will respond to a warmer world.

Off to Garwood Valley

Been a busy week back at McMurdo Station, getting camp in order for a weeklong trip to Garwood Valley. We're leaving the comforts of station life behind (dinner is running for over 1,000 scientists and support personnel in the galley, or dining hall, right now), and the structure of a well-organized field camp (like Lake Hoare) for a wild part of the Dry Valleys. We'll be putting in a small tent camp to explore buried ice deposits left over from the last glacial maximum. A toe of ice was left in Garwood Valley about 10,000 years ago. Locked in it is evidence of how Antarctica responded to sudden warming at the end of the ice age.

To give you an idea of what goes in to making a remote research camp work, I've attached the shopping list I took to the food issue room today. McMurdo has a little "supermarket" where you can stock up on supplies for the tent camp. All said, breakfast, lunch, and dinner for 4 people for 7 days came to 199 lbs. of food. It might not be the best chow on the continent, but there's sure a lot of it!


Friday Night--Burrito

2 lbs ground beef
1 bag cheese
1 box rice
salsa
1 bag fajita veg
1 bag tortillas
1 can refried beans

Saturday Night--Stirfry

4 can chicken
1 bag asian veg
soy sauce
chili
10 ramen

(double-up for weather?)

Sunday Night--Steak and Fish

4 x steak
4 x halibut
latkes: frozen hashbrowns bag
egg powder
italian seasoning
salt
pepper

Monday Night--Chili

2 lbs ground beef
2 cans kidney beans
chili powder
2 small green chili cans
1 can tomato garlic and onion
1 can tomato mexican
1 block tastee

Tuesday Night--Spaghetti

2 lbs pasta (not spaghetti!)
2 packages meatballs
1 can tomato sauce
1 can garlic and onion tomato
1 tomato powder packet

Wednesday Night--Thanksgiving

4 cans turkey
mashies mix
gravy mix
1 bag stuffing
10 oz.peas

(double-up for weather delay)

Thursday Night--Chicken Parm

12 breaded patties
1 bag mozzarella
2 packets tomato powder
2 lbs spaghetti

Friday Night--Steak and Fish

beef jerky
tastee cheddar cheese
cookies
cans of soup
olive oil
peanut butter
jelly
cabin bread
gorp
granola
milkman instant milk
bagels x 1 dozen
cocoa
raro (like Tang)
butter (1 box)
olive oil (small)
oatmeal x 1 box