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TOPIC: Giant drill ship

Blobrana

L

Posts: 131433

Date: Jun 18 19:43 2006

Project MoHole	Permalink

The small gray and black rocks stored in 3-foot-long clear plastic tubes at a Texas A&M University lab could be mistaken for the leftovers after a kitchen countertop installation. Scientists hope this latest effort in the generations-old attempt to get closer to the centre of the planet — achieved as part of the world‘s biggest earth science program — can help unlock some of earth‘s longest-held secrets. Neil R.Banerjee, from the University of Alberta, Canada, said the oceanic work adds to the knowledge about climate, earthquakes and of how mountains are built. "Consider 60 percent of the earth surface is made in this fashion. What‘s exciting to geologists is, although it‘s frozen now, it‘ll provide a record of this fundamental planetary process which is responsible for paving the floors of the oceans" - Jeff Fox, director of the Integrated Ocean Drilling Program. They went back in July 2005, deepened their hole, and returned again in November, wearing out 25 paint bucket-sized drill bits to get about a mile into the sea floor. That was when, for the first time, they cracked the magma chamber. Hundreds of feet of core from the hole was recovered and will be analysed, but only 9 metres is gabbros. Among the rocks is one piece marked by a distinct white stripe showing a boundary where liquids cooled at different times. Fox said the pebbles are priceless. More than a century ago, the thought of reaching deep inside the earth was the stuff of fantasy. In the late 1950s, an ambitious effort dubbed Project Mohole was an attempt to go inward at the same time the nation‘s fledgling space program was moving outward. The goal was to retrieve a sample of the earth‘s mantle, the level beneath the earth‘s crust and above the core. After eight years, with only one of three phases of the project complete, Congress cut off the money. Mohole was a dry hole. Unlike Verne‘s scientists, whose volcano gateway in 1864 was in Iceland, the gabbros recovery team headed for the tropics and the ocean with scientists representing 20 countries. "What drives that fundamentally is the record of the earth‘s history is written in greater clarity in the sediments of rocks on the sea floor than anywhere else" - Jeff Fox. Doug Wilson, a geophysicist from the University of California at Santa Barbara and a co-chief scientist on an earlier expedition, studied the magnetic properties of the ocean crust to help determine a suitable drilling site. "Finding the right place (the 15 million-year-old region of the Pacific Ocean floor) to drill was probably key to our success" - Doug Wilson. Researchers have determined areas of the ocean are the most attractive drilling sites because the tectonic plates that make up the crust are far narrower than on land. The ship costs A&M about $45 million a year, or some $130,000 a day, making the program the largest earth science program in the world both in size of international partners and annual budget. The program is backed by two lead agencies, the U.S. National Science Foundation and Japan‘s Ministry of Education, Culture, Sports, Science and Technology, plus a consortium of 17 European countries and China. Scientists already are making proposals to return for deeper drilling, perhaps as early as 2009. In the meantime, as staff scientist, Banerjee has the difficult task of helping determine who among the researchers gets a piece of the rocks. Source __________________

Blobrana

L

Posts: 131433

Date: Apr 22 17:43 2006

Ocean Crust	Permalink

An international team of scientists aboard the research drilling ship JOIDES Resolution has - for the first time - recovered black rocks known as gabbros from intact ocean crust. Supported by the Integrated Ocean Drilling Program (IODP), the scientists drilled through the volcanic rock that forms the Earth's crust to reach a fossil magma chamber lying 1.4 kilometres beneath the seafloor. "By sampling a complete section of the upper oceanic crust, we've achieved a goal scientists have pursued for over 40 years, since the days of Project MoHole. Our accomplishment will ultimately help science answer the important question, 'how is new ocean crust formed?'" - Damon Teagle, National Oceanography Centre, University of Southampton, UK, and co-chief scientist of this drilling expedition. Formation of ocean crust is a key process in the cycle of plate tectonics; it constantly 'repaves' the Earth's surface, builds mountains, and leads to earthquakes and volcanoes. Project MoHole, begun in the 1950s, aimed to drill all the way through the ocean crust, into the Earth's mantle. "Having this sample from the deep fossil magma chamber allows us to compare its composition to the overlying lavas. It will help explain whether ocean crust, which is about six- to seven- kilometres thick, is formed from one high-level magma chamber, or from a series of stacked magma lenses" - Jeffrey Alt, University of Michigan and co-chief scientist on an earlier leg of this mission He emphasises that "the size and geometry of the melt lens affects not only the composition and thermal structure of the ocean crust, but also the vigour of hydrothermal circulation of seawater through the crust." Alt states that such systems lead to spectacular black-smoker vents--modern analogues of ancient copper deposits and deep-ocean oases that support exotic life. "These results, coming from the structural heart of Pacific crust, confirm ideas from seismologic interpretation about how fast-spreading oceanic crust is built. They refine our understanding of the relationship between seismic velocity and crustal rock composition, and open new vistas for investigating the origin of lower oceanic crust, best addressed by deeper drilling."- IODP Program Director James Allan at the U.S. National Science Foundation, which co-funds IODP research with Japan. NSF and Japan each provide a scientific drilling vessel to IODP for research teams. Geophysical theories have long projected that oceanic magma chambers freeze to form coarse-grained, black rocks known as gabbros, commonly used for facing stones on buildings and kitchen countertops. Although gabbros have been sampled elsewhere in the oceans, where faulting and tectonic movement have brought them closer to the seafloor, this is the first time that gabbros have been recovered from intact ocean crust. "Drilling this deep hole in the eastern Pacific is a rare opportunity to calibrate remote geophysical measurements such as seismic travel time or magnetic field with direct observations of real rocks" - geophysicist Doug Wilson, University of California, Santa Barbara. Co-chief scientist on an earlier expedition to the same drilling site, Wilson was instrumental in helping to select the site drilled. His contributed to the research mission thorough study of the ocean crust's magnetic properties. "Finding the right place to drill was probably key to our success. The research team identified a 15-million-year-old region of the Pacific Ocean that formed when the East Pacific Rise was spreading at a 'superfast' rate (more than 200 millimetres per year), faster than any mid-ocean ridge on Earth today. We planned to exploit a partially tested geophysical observation that magma chambers should be closest to the Earth's surface, in crust formed at the fastest spreading rate. If that theory were to be correct; then we should only need to drill a relatively shallow hole--compared to anywhere else--to reach gabbros" - Doug Wilson. Wilson and colleagues proved the theory correct. Following three years of research and multiple trips to the site in question, the borehole that rendered the magma chamber is now more than 1,500 meters deep; it took nearly five months at sea to drill. Twenty-five hardened steel and tungsten carbide drill bits were used before the scientists' work was complete. The rocks directly above the frozen magma chamber were extremely hard because they had been baked by the underlying magmas, much like tempered steel. IODP scientists want to return to the site of the unearthed magma chamber to explore deeper, in hopes of finding more secrets hidden deep within the ocean's crust. Source __________________

Blobrana

L

Posts: 131433

Date: Dec 16 13:08 2005

kussakusen chikyu	Permalink

An ambitious Japanese-led project is set to drill deeper into the Earth's surface than ever before will be a breakthrough in detecting earthquakes including Tokyo's dreaded "Big One". The deep-sea drilling vessel Chikyu docked in Yokohama on Thursday after ending its first training mission at sea since being built in July at a cost of 500 million dollars. The 57,500-ton Chikyu, which means the Earth in Japanese, is scheduled to embark in September 2007 on a voyage to collect the first samples of the Earth's mantle. The project, led by Japan and the United States with the participation of China and the European Union, seeks clues on primitive organisms that were the forerunners of life and on the tectonic plates. The Chikyu Credit JAMSTEC "This is like an Apollo project under the Earth. The idea of the project came out half a century ago but failed halfway while the real Apollo project was carried out successfully. So this is a second and serious attempt to complete another key exploration for mankind. We are so excited to witness the mantle for the first time." - Kan Aoike, staff scientist. The Earth is made up of a crust, a mantle, an outer core and an inner core. The satellite-equipped vessel is equipped with a 121-meter drill tower that can dig 7,000 meters below the seabed, nearly three times as deep as its predecessors. "All these (samples) give us different ideas for how the climate changed over time, the position of the continents, what kind of land plants were living on the Earth, what's the potential for oil" - Daniel Curewitz, US scientist working on the project. "For Japan the most important thing is to drill through areas where plates are overlapping so that we can monitor an earthquake directly. I presume this will help predict an earthquake, which will be a breakthrough in seismology. Even if we cannot predict it, we can get data in advance of an initial crack from an earthquake" - Asahiko Taira, director-general of the project. Japan experiences 20 percent of the world's major earthquakes. As a first drilling spot, the operator chose the seabed some 600 kilometres southwest of Tokyo, where many experts say an earthquake measuring eight on the Richter scale will occur sometime in the near future. In 1944 and 1946, more than 2,000 people in total were killed in two big earthquakes and tsunami in the seabed area known as the Nankai Trough, a boundary where two plates slide past each other. The seabed off Sumatra in Indonesia that was the scene of the massive earthquake a year ago that triggered the Indian Ocean tsunami, is also a potential drilling spot in the future. Oceanic drilling is preferred over land drilling because the crust at the seabed is thinner and allows for deeper digs into the crust and mantle. Chikyu uses technology that exists for oil drilling, but is specially equipped to prevent damage from sudden bursts if it accidentally strikes oil or gas reserves. Some 150 crew are scheduled to make the first official voyage in 2007. The ship and its drill pipes are rigged to stay stable by adjusting to the rolling motions from the drilling and waves. Read More __________________

Blobrana

L

Posts: 131433

Date: Jun 4 09:47 2005

Giant drill ship	Permalink

Japanese scientists are attempting to explore the centre of the Earth. Using a giant drill ship launched next month, the researchers aim to be the first to punch a hole through the rocky crust that covers our planet and to reach the mantle below. Using a giant drill ship launched next month, the researchers aim to be the first to punch a hole through the rocky crust that covers our planet and to reach the mantle below. The team wants to retrieve samples from the mantle, six miles down, to learn more about what triggers undersea earthquakes. They hope to study the deep rocks and mud for records of past climate change and to see if the deepest regions of Earth could harbour life. Asahiko Taira, director general of the Centre for Deep Earth Exploration in Yokohama, near Tokyo, said: "One of the main purposes of doing this is finding deep bacteria within the ocean crust and upper mantle. We believe there has to be life there. It's the same mission as searching for life on Mars." Rocks in the upper mantle produce compounds essential for life when they react with seawater. "This is a system which we believe created early life. There may be a chance that we can catch the origin of life still taking place today" - Prof Asahiko Taira. The 57,500-tonne drill ship Chikyu (Japanese for Earth) is being prepared in the southern port of Nagasaki. Two-thirds the length of the Titanic, it is fitted with technology borrowed from the oil industry that will allow it to bore through 7,000 metres of crust below the seabed while floating in 2,500 metres of water - requiring a drill pipe 25 times the height of the Empire State building. The deepest hole drilled through the seabed so far reached 2,111 metres. After final sea trials this year, the scientists will set sail for the deep Pacific where the Earth's crust is thinnest. Drilling is expected to begin next year. It could take more than a year to drive through miles of crust and reach the mantle, so the ship is fitted with six rotating thrusters controlled by GPS satellites to keep it directly over the hole. The drill is surrounded by a sleeve that contains a shock-absorbing chemical mud, and a blow-out valve will protect it should the team strike oil or superheated rock in the crust. The project is part of an international effort called the Integrated Ocean Drilling Programme which also involves the US and Europe. Shinichi Kuramoto, one of the Yokohama team, said Chikyu's main objective is to retrieve mantle samples for analysis. "Humans have brought back lunar rocks to understand the universe, yet we have never reached the mantle which accounts for most of earth." Previously undiscovered bacteria that can survive the anticipated 100C temperatures of the upper mantle could be useful on the surface. Heatproof enzymes isolated from bugs brought back by earlier Japanese drill missions are now used in washing powders. Cores of rock and sediment from the so-called "earthquake nest" where the mantle meets the crust could also help geologists understand seismic events, and to perhaps give more warning. "We can estimate how frequently marine sliding or earthquakes occur from learning the history of earth but we still don't know when they will occur in the future. We take cores to better understand the mechanisms involved," - Dr Shinichi Kuramoto. Sensors placed in the borehole could detect changes in strain, tilt and pressure in the ground miles below the surface. "That will be a great advantage in giving us a few days or hours warning before something happens. Current warning systems in Japan only warn us 10 minutes before a large earthquake strikes. We need real-time data from the exact point." __________________

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