Science and Technology
MOHOLE – Phase I 

In 1957, Walter H. Munk, a member of the National Science Foundation (NSF) Earth Sciences Panel, proposed drilling through the earth’s upper crust to sample the Mohorovicic discontinuity, known as the Moho. The discontinuity separates the earth’s crust layer from the earth’s mantle. The mantle is believed to be approximately 1,800 miles thick, encapsulating the earth’s core. Sampling the Moho and the adjoining mantle would provide new scientific information related to the earth’s origin.

The earth’s crust averages about 125,000 feet thick under the continents, but is only 15,000 to 20,000 feet thick under the deeper ocean basins. Consequently, Dr. Munk and his fellow scientists believed the drilling program should be carried out in the ocean using a floating drilling vessel. Another scientist, Willard Bascom, became very interested in the ‘Mohole’ project and took over leadership of a group seeking NSF funding to perform a $15,000 feasibility study. Once NSF agreed to pay for the 1958 study, Willard Bascom’s group commenced working with Global Marine’s Robert Bauer on the design adaptations necessary for Global’s CUSS I drillship to perform anchorless coring operations. They proposed conducting the tests in 11,600 feet of water to demonstrate the feasibility of performing actual drilling operations in the very deep ocean.

In March 1960, the NSF approved the CUSS I’s modification funding and in March 1961 the CUSS I successfully took the first core penetrating 110 feet into the top of the earth’s crust. The coring was done utilizing manually controlled dynamic positioning in 11,700 feet of water near Guadalupe Island, off the West Coast of Baja, California. The Phase I program resulted in 5 holes, some penetrating over 1,000 feet, and retrieving 28 scientifically valuable cores. The cores included 44 feet of volcanic rock, which was the first time in history the hard rock of the earth’s crust had been penetrated.  Phase I was the beginning of ultra deepwater drilling and successfully demonstrated that the Mohole could be drilled. 

Recognizing the pioneering efforts of the following individuals and companies that contributed to this technology:

Willard Bascom, Robert Bauer, Walter H. Munk  Global Marine (now Transocean), National Science Foundation