Word: drill
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
Target Mohole. This effort is part of Project Mohole, which will cost more than $20 million. It is backed by the National Science Foundation, and its goal is to drill clear through the earth's crust to the "Moho,"* the boundary between the comparatively light rocks of the crust and the much denser mantle, which extends downward for i ,800 miles and whose properties are largely unknown. Geophysicists are sure that even one hole drilled to the Moho will tell invaluable volumes about the history, structure, content and behavior of the earth...
...easiest place to start drilling would be on land, but unfortunately the crust under the continents and the oceanic islands is too thick (up to 20 miles) to be penetrated. Under many deep parts of the ocean the crust is only three miles thick-and for this reason the leaders of Project Mohole decided that the drilling should be done from a special ship floating in three miles of water. The ship cannot be held over the drill hole by anchor cables extending sideways. Such cables hang in curves and would yield too much to changes of pull from winds...
Belly & Head. The essentials of this system, plus a specially designed drill rig, got their first big test last fortnight when Cuss I, owned by Global Marine Exploration Co. and originally designed to drill oil wells in much shallower water, stationed herself off La Jolla, where the ocean is 3,140 ft. deep. Four outboard propellers driven by 200-h.p. engines churned the water fore and aft, but, according to plan, the ship did not move. Buoys moored 1,000 ft. away carried transponders to repeat sonar waves sent to them underwater. Pilot Ernie Cantu watched a sonarscope showing...
...Jolla the Cuss I drilled five holes, the deepest 1,035 ft. Cores of sand, mud and soft stone with a few fossils were brought up. In spite of the loss of two diamond-studded drill points, the tests were considered highly successful...
Never had any drilling been done in such deep water. The new tests that will start soon off Guadalupe will show what modifications of ship and drilling apparatus will be needed to drill through miles of rock down to the Moho itself...