Deep Sea Drilling Vessel (D/V) CHIKYU is the first riser equipped scientific drilling vessel
built for science at the planning stage. It is capable of drilling up to 7,000m deep sea floor and aim
to the mantle and seismogenic zone. CHIKYU explores the Earth as the main plat form of the Integrated
Ocean Drilling Program (IODP).
The earth has experienced a number of great environmental changes. The
evidence remains under the deep seafloor. The deep sea drilling research open the new frontier of earth
and life science for future of mankind by revealing the system of major earthquakes, global changes,
origin of life.
the earthquake mechanism requires surveys, direct observations, samples and monitoring under the earth
at the plate boundary. D/V CHIKYU, because it can drill to the seismogenic zone, is the primary
tool to obtain these crucial pieces of information. We aim for establishment of earthquake information
transmission system by installation of monitoring machines in the borehole.
First life was born in the primitive earth under the high temperature, high pressure and no oxygen.
There still is the environment similar to the primitive earth in the deep part of the present earth.
Research into these microbes in extreme environments may resolve the origin and evolution of life on
Earth. It is one of the most important life science targets of D/V CHIKYU.
one of the main objectives of D/V CHIKYU is to drill through the earth’s crust and reach
the mantle, where no one has ever explored before. The earth has been continuously changing its aspect
with continental drift and large-scale volcanic activity etc. The mantle is considered to play an important
role for the Earth system. We will open the door for direct understanding the relationship between global-scale
environmental change and mantle processes.
What is mantle?
A main layer structure that makes up the solid earth. The mantle extends up to 2,900km beneath the crust,
and accounts for 80% of the total mass of the Earth. Huge volume of magmatic convection ascending (super
plume) and descending (cold plume) in the mantle is considered to play an important role for the Earth’s
environment changes, however, human kind has never reached the mantle yet.
cores obtained by D/V CHIKYU are valuable records of global environmental change. Detailed analysis
of such records enables the understanding of global change mechanisms and prediction of future change.