Continental scientific drilling projects were promoted actively around the world in the latter part of the 20th century. The super deep drilling projects developed drilling technologies, and highlighted a lack of understanding of the Earth's interior. The International Continental Scientific Drilling Program was initiated to promote continental scientific drilling projects globally and international cooperation. Geology needs to be taken into consideration more and technology for preventing bore-hole break-outs needs to be developed in continental drilling projects. More work is required to take a fresh look at the Earth based on the facts obtained from the surface. Continental scientific drilling is a potentially important tool for undertaking this study of the Earth in areas such as the subsiding atoll concept and ocean floor spreading. Because accretion and arc magmatism accompanying subduction of the ocean floor are important in the formation of continental crust, continental scientific drill projects on the Japanese Islands will play an important role in geology and human society.
