is a Japanese scientific drilling ship built for the Integrated Ocean Drilling Program (IODP). The vessel is designed to ultimately

drill A drill is a tool used for making round holes or driving fasteners. It is fitted with a drill bit for making holes, or a screwdriver bit for securing fasteners. Historically, they were powered by hand, and later mains power, but cordless b ...

beneath the seabed, where the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

is much thinner, and into the

Earth's mantle Earth's mantle is a layer of silicate mineral, silicate rock between the Earth's crust, crust and the Earth's outer core, outer core. It has a mass of and makes up 67% of the mass of Earth. It has a thickness of making up about 46% of Earth's ...

, deeper than any other hole drilled in the ocean thus far. While the planned depth of the hole is significantly less than the Russian

Kola Superdeep Borehole The Kola Superdeep Borehole SG-3 () is the deepest human-made hole on Earth (since 1979), which attained maximum true vertical depth of in 1989. It is the result of a scientific drilling effort to penetrate as deeply as possible into the ...

(which reached depth on land), the scientific results are expected to be much more interesting since the regions targeted by ''Chikyū'' include some of the most seismically active regions of the world. Other deep holes have been drilled by the drill ship JOIDES Resolution during the Deep Sea Drilling Project and the Ocean Drilling Program.

Operation

The Japanese part of the IODP program is called , Japanese for "Earth Discovery". ''Chikyū'' is operated by the Centre for Deep Earth Research (CDEX), a subdivision of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC). JAMSTEC also operates the DSV Shinkai, Earth Simulator

supercomputer A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instruc ...

and other marine scientific research projects. CDEX is responsible for the services to support activities including on-board staffing, data management for core samples and logging; implements engineering site surveys; and conducts engineering developments. CDEX contracts with the Mantle Quest Japan Company for the navigation of the ship. The ''Chikyū Hakken'' program is part of an international scientific collaborative effort with scientists from the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, ECORD, a consortium consisting of several European countries and Canada,

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

, Australia and New Zealand (ANZIC), and

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

Design

D/V ''Chikyū'' was built by the

Mitsui Engineering & Shipbuilding () is a Japanese heavy industries company. Despite its name, it no longer builds ships and now focuses mainly on production of high-value ship equipment such as Marine propulsion, engines and automated gantry cranes. Mitsui E&S is the largest ...

and launched on 18 January 2002 in

Nagasaki, Nagasaki , officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan. Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...

. The ship was outfitted by the

Mitsubishi Heavy Industries is a Japanese Multinational corporation, multinational engineering, electrical equipment and electronics corporation headquartered in Tokyo, Japan. MHI is one of the core companies of the Mitsubishi Group and its automobile division is the prede ...

and delivered to JAMSTEC on 29 July 2005. The hull of the ship is long, in width, high, and has an approximate gross tonnage of about . The ship has a draft of and a maximum cruising speed of . The amidships derrick is above sea level, and the top drive has a lifting capacity of . Its complement of 150 crew are divided between 100 operators and 50 science personnel, with at sea crew changes handled by

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

transfer. Key innovations include a GPS system and six adjustable computer controlled azimuth thrusters ( in diameter) that enable precise positioning to maintain a stable platform during deep water drilling. The maximum drilling water depth for riser drilling is and can support a drill string up to long. The helipad can serve very large helicopters transporting as many as 30 persons per landing.

History

The D/V ''Chikyū'' was built for deep-sea geological scientific research, which now includes not only research of

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

-generating zones in the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

's crust but also hydrothermal ventsThe Deep Hot Biosphere Drilling
, Deep Hot Biosphere hydrothermal vents. and subsea methane hydrate research. On 16 November 2007 ''Chikyū'' began drilling the transect as planned, reaching at the site of a future deep subsea floor observatory. The first stage of four NanTroSEIZE Stages was completed in February 2008. The whole project was envisioned to be completed by 2012. The ship was damaged by the

2011 Tōhoku earthquake and tsunami On 11 March 2011, at 14:46:24 Japan Standard Time, JST (05:46:24 UTC), a 9.0–9.1 Submarine earthquake, undersea megathrust earthquake occurred in the Pacific Ocean, east of the Oshika Peninsula of the Tōhoku region. It lasted approx ...

on 11 March 2011. The ship was moored in the port of

Hachinohe, Aomori is a Cities of Japan, city located in Aomori Prefecture, Japan. , the city had an estimated population of 213,453 in 110,121 households, and a population density of . As of October 2020, Hachinohe is Aomori Prefecture's second largest city by ...

. The tsunami wave pushed the Chikyu over the pier and the vessel sustained some damage. One of the six thrusters, No.5, was damaged and a hole was made in the bottom. Local preliminary school children who were visiting the ship at the time of the earthquake spent one night on board and were rescued by

Japan Self-Defense Forces The are the military forces of Japan. Established in 1954, the JSDF comprises the Japan Ground Self-Defense Force, the Japan Maritime Self-Defense Force, and the Japan Air Self-Defense Force. They are controlled by the Ministry of Defense ...

helicopters next day. The ship was repaired at a dock in Yokohama (Mitsubishi Heavy Industries) and returned to service in June 2011.

World record

According to the IODP, on 27 April 2012, ''Chikyū'' drilled to a depth of below sea level, setting a new world record for deep-sea drilling. This record has since been surpassed by the ill-fated ''

Deepwater Horizon ''Deepwater Horizon'' was an ultra-deepwater, Dynamic positioning, dynamically positioned, Semi-submersible platform, semi-submersible offshore drilling Oil platform, rig owned by Transocean and operated by the BP company. On 20 April 2010, ...

'' mobile offshore drilling unit, operating on the Tiber prospect in the Mississippi Canyon Field, United States Gulf of Mexico, when it achieved a world record for total length for a vertical drilling string of . The previous record was held by the U.S. vessel '' Glomar Challenger'', which in 1978 drilled to below sea level in the

Mariana Trench The Mariana Trench is an oceanic trench located in the western Pacific Ocean, about east of the Mariana Islands; it is the deep sea, deepest oceanic trench on Earth. It is crescent-shaped and measures about in length and in width. The maxi ...

. On 6 September 2012, scientific deep sea drilling vessel ''Chikyū'' set a new world record by drilling down and obtaining rock samples from deeper than 2,111 meters below the seafloor off the Shimokita Peninsula of Japan in the northwest Pacific Ocean. In addition, the 27 April 2012 drilling set a record for the depth of water for drilling of . That record still stands.

In popular culture

The D/V ''Chikyū'' is featured and plays a pivotal role in the 2006 film '' Sinking of Japan''.

References

External links

The Biggest Dig: Japan builds a ship to drill to the earth's mantle
– Scientific American (September 2005)

Official Page for Integrated Ocean Drilling Program

JAMSTEC.

JAMSTEC.

IODP Riser Vessel homepage

T-Limit Expedition
{{DEFAULTSORT:Chikyu Science and technology in Japan Structure of the Earth 2002 ships Japan Agency for Marine-Earth Science and Technology Drillships