Today the ice closed in on the vertical chamber completely and in a last moment Ben attempted to get some data on the closure rate. He found a curved section of ice and repeated diameter measurements over a period of several hours. It is amazing in the short amount of time how much the ice actually can move. The pressure of 600 feet of solid ice really amazes me, I cannot even imagine what the rock under glaciers thousands of meter thick must feel. It is no wonder that valleys are carved throughout the world this way, glaciers have a tremendous influence on the shape of continents. Later in the day I help out with the accelerometers. After testing it appears two of them are not recording correctly. A closer inspection shows that when we lowered the cables through the granite we neglected to cover the USB computer ends. Since there was a battery installed already and the USB cord had power, we unfortunately created a conduction path between two electrodes. This caused a deposit of copper oxide on the leads due to the moisture that got in and fried the unit. Two weeks of work here and one silly mistake of not covering the leads from water! Mark brought along a couple of spares and we solder the leads in the tunnel... and after some work, one of the accelerometers becomes functional. There is still a problem with a very expensive accelerometer that appears to have stopped working. Pete is working on this. We are not sure if it is the unit or some wiring issues.
In the afternoon Miriam wants to practice a fire drill. NVE has worked hard this year making the tunnel safe, and the new system still has some bugs to work out. Some of us are sent up the tunnel to the ice and wait for the flashing red light... it arrives a few minutes after the fire alarm is set.. a small problem! Then it is off to the safe room, it is here where we are supposed to gather with our oxygen tanks. The room has a compressed air tank inside that keeps the air pressure inside higher than the outside so that no smoke gets inside.
The days are slowing now as there is little to do but wait for the ice to reform in the tunnel.