Scientific drilling is an indispensable tool of modern Earth science - search, as it provides the only means of obtaining direct information on processes operating at depth. Drilling allows for the determination of - situ properties of solid materials and fluids and permits testing of hypot- ses and models derived from surface observations. In addition, drill holes may be used as a natural laboratory for experiments and as observatories for long-term monitoring of on-going active processes. Earth drilling, therefore, plays a critical role in scientific research directed towards - proved...