We liked yesterday so much aboard the Palmer that we are having it again! I am no longer writing from the future, since we reset our time to account for the passing of the date line. If you have been following this journal since the beginning, you might remember that I completely missed my sons second birthday when I went from February 8 to February 10 in a couple of hours. It is time to recover that lost day, so we are having two March 17!
We have been sailing through the ice for the past two days and the views have been great. We did not get to see the continent from the southern most position we achieved since it was very cloudy. It has been very cloudy for many days, but today the sky broke into wonderful sunshine!
The sun finally came out today and we enjoyed the views of the ice field
There is no science today in the Palmer, despite the calm waters and the sunny day. We are steaming towards a placer where we will retrieve a mooring. I will talk in more detail about the mooring tomorrow, when we get it out of the water. All you need to know now is that it is a very long cable moored to the bottom of the sea and kept vertical by several floats that are underwater. Alex attached some oceanographic instruments when they left it last year. It is time to bring them back home.
People in the science party are resting and enjoying the great views. It seems strange to see people who are normally asleep in the middle of the day as tourists walking around and taking pictures on the deck. It is nice for them to have a rest day, specially when the weather is so nice, even if colder than before. A yoga session has been organized at 3:00 pm, and a chick flick session at 10:00 pm.
But today I want to write about the big highlight of the night. The launching of an XBT. XBT stands for 'expendable bathythermograph'. It is a fancy name for a thermometer that is thrown overboard and never recovered (therefore the X in the name). The device is connected to the ship through a very thin wire, through which it sends the temperature reading as it falls into the depths. The XBT is calibrated to fall through the water at a known speed, so we can generate a profile of depth and temperature at one spot. We will be launching more XBTs tomorrow when we go from one mooring to the next.
Jim wanted to have the graduate students and me be the ones deploying the XBTs. I attended the training session at 11:330 pm last night, when the first XBT was launched. Safety is extremely important when working on deck, and the launching seemed to demand extra precautions. We got our floating jackets, ear muffs, helmets and eye-protection. Eric was chosen as a volunteer to give it a try, so he was dressed with extra protective gear.
Eric, our designated volunteer, gearing up for the risky launching of the XBT
He had to wear a full face cover and the XBT Team's special armor. Alex said the sound of the explosion would be very loud, and therefore the need for the earmuffs. Mike told us how to load the XBT on the launcher that, as you can see, looked like a gun. He told Eric how to position his feet to better absorb the kick from the launcher, and told the rest of us to step back a couple of meters more. He called the bridge through the radio and we were set.
I was very keen on taking a good picture of the XBT flying from the stern into the night sky. and perhaps some flames coming out of the launcher. My finger was nervously on the shutter release button ready to push it as soon as would hear the detonation. I was so concentrated that I missed the anticlimactic deployment in which Eric tilted the launcher down so the XBT could onto the water surface aided by the gravitational force.
All that the fancy looking launcher does is to pierce through a thick layer of wax on the spooler and make electrical contact. The wax is place there so the small and delicate metal components do not rust through the years in which the XBT is stored.
This is the XBT spool that is left behind on the ship. I removed the sticker over the wax (white material) and placed it on the side so you could see the three holes made by the launcher. The brownish filament is the copper cable for receiving the signal.
The protective gear and important instructions were a prank to which we all fell like good naive people that we are. I am looking forward to the next XBT launch.