December 1, 2006

Another great day here in the Dry Valleys. We were treated to a rare snowfall; the cooler temperatures have re-solidified most of the moat making crossing it a bit easier again. Today's mission was to finish laying out our transect line, to take photographs of the collection areas along the transect line and to record depths at each site, to relaunch Hal, and to collect water samples at each of the transect "stations". All tasks were successfully accomplished!

	Peter was diving during the snowfall this morning. Peter is leaving tomorrow, so it was fitting that his final dive feel like an "Antarctic dive" (chilly and snowy)!
The ice hole started to refreeze while Peter was diving.
Freezing some more.... don't worry - it's really VERY thin slush more than ice! It just looks a little freaky!
See - we let Peter out again!
	I thought a little encouragement might help my dry suit. Just like in the story The Little Engine That Could - when the train struggling to get up the mountain chanted "I think I can, I think I can," I tattooed the chant "I am a dry suit, I am a dry suit" onto the back of my suit! (It didn't help! - not sure what's up with this... after repairs, the last dive was almost completely dry - this one I got soaked in the arms again - UGH!)
	Prepare for launch sequence! This is Hal, ready to go back in the water with new probes. We reviewed the plan for getting him into the water without damaging the probes. One bump, and the probes are history!
	The first step is to raise Hal into the air and prevent him from swinging.
	Once in the air, we walk Hal over to the top of the dive hole. There is a pulley system in place to keep tension (or release tension if needed) on the main line as well as to direct Hal left or right along the cross bar.
	Lowering Hal into the water. We have to be careful not only not to bump the edge of the ice tube, but also avoid hitting any ice chunks that are forming in the water. These probes are VERY fragile - it doesn't take much to break them!
	Kay hangs out over the hole to direct the descent into the lake! Don't bump the edges!
Once Hal was launched, Kay dove in order to move Hal away from the bottom of the hole and to his new location. This is done by attaching a lift bag, raising Hal in the water to just below the ice, swimming with Hal to the next location, and then letting air out of the lift bag to do a "lunar landing" with Hal in the new spot. (We joked about going out for coffee while Kay was diving! - No - we would NEVER do that!)
	Peter checks the coms as I get ready to dive and collect water samples from just above the mat at each of the transect sites. This is a challenging task; you must be close enough to the mat to collect samples from just above it, but not touch the mat! This requires considerable buoyancy control. You must get yourself just above the mat so that when you breath in, you rise up just a little, and when you exhale, you sink down just a little - not enough to touch the mat! It's actually quite relaxing!
The water samples were all collected in plastic syringes. While I was diving, Ian, Kay, and Peter recorded the information I radioed up about which station I was at and what number syringe I was collecting the sample in; it's important to keep data organized. Data quickly becomes useless if you lose track of where everything came from.
	Once I returned with the samples, Kay immediately began running pH and conductivity tests on the water from each syringe.
	Ian records the data as Kay relays the information. Again, it's very important to keep accurate records.
The water samples were then brought back to the lab to be filtered.
	Ian begins filtering each sample.
Because Peter is scheduled to leave tomorrow, we decided to take a group photo today. From left to right: Ian, Peter, Kay, and me. Thanks Peter! (Thanks also to Sitoshi for taking the photo!)
Family, friends, and past 8th graders will "get" this photo; I had to do it!