Today the task was to melt the ice in the vertical chamber for the last time and install the accelerometer cables before the ice encloses the area again. Already the friction plate that we installed the day before has partially been encased in ice. We take advantage of the open chamber to snap our last photos with the blue ice. This part of the chamber will likely be sealed off tomorrow because of the narrow passageway between the two main chambers of the ice.
The connecting tunnel to the vertical shaft chamber area has just enough room to get through. Behind me is where the accelerometers will be installed.
As the ice cave is melted, the glacier has no pressure on one side so the ice begins to buckle, and here the sediment layer has turned vertical.
The melting has made a large enough space for us all to discuss the placement of the accelerometers.
It is another long day, there are several hours of waiting for the melt to finish, repairing and epoxying cables and hauling things. We decide to install the accelerometers after dinner. Each of the long cables are dropped through the holes bored into the granite. The cables are very long on purpose, the idea is that as the glacier moves it will pull the cables with it. One end of the cable has the accelerometer sensor on it with a data logger encased in a steel pipe with the
battery pack I soldered together. The other end of the cable has a USB interface that connects to the computer data logging system. It should be good for at least twenty days, and hopefully longer, the only limitation is the current draw. To install the accelerometers in the ice you take an ordinary pressure washer hose and drive hot water horizontally for ten minutes until a hole is open large enough for the metal ends to fit inside. It is a quick process that Mark finishes professionally.
The cables are routed through the granite floor to a tunnel beneath.
It is still pretty tight quarters where the boreholes are for the cables to run through. Ben can barely sit in this small space. In his hands he is holding the metal casing, inside of these are the accelerometers and processor and batteries.
The exit spot for the cables, above this is about ten feet of granite and then the chamber. The cords are extra long because the glacier will begin to move and drag these cables with it.
The end of the day is a long walk back to the sleeping quarters. I have not seen daylight for a long while!
The deep blue of the ice always amazes me.
You always have to wear a miners hat and light. It is rather dark without it. You can see it is a bit cold but not so bad.