Electrochaude: Recent Development in Borehole Drilling

In order to study different aspects of glaciers, the scientists need good quality cores, but also holes bored in the ice. The LGGE has developed core drilling systems and different kinds of boring systems:

• A hot water drill very efficient but bulky and heavy equipment. Its transportation from the valley to glaciers needs the use of a helicopter.
• A steam drill, a light and compact device, portable by men, which is used to drive in wooden stakes. Its efficiency decreases below 15 m deep because of the hydrostatic pressure of the water in the hole.
• A hot point drill, in which an electrical heating element is embeded in silver. It allowed us to measure ice thickness and to put in metallic wires for deformation measurements by inclinometry. But it as three main disadvantages:
  1. the cost of the head due to both the silver price and the sophisticated fabrication.
  2. it can be overheated if not immersed in water and can be destroyed.
  3. it loses its efficiency when the ice contains much rock debris.

For these reasons, we developed a new system called Electrochaude.