Deep Sea Drilling Project

The Deep Sea Drilling Project (DSDP) was an ocean drilling project operated from 1968 to 1983. The program was a success, as evidenced by the data and publications that have resulted from it. The data are now hosted by Texas A&M University, although the program was coordinated by the Scripps Institution of Oceanography at the University of California, San Diego. DSDP provided crucial data to support the seafloor spreading hypothesis and helped to prove the theory of plate tectonics. DSDP was the first of three international scientific ocean drilling programs that have operated over more than 40 years.

GlomarChallengerBW
Glomar Challenger

History

The initial contract between the National Science Foundation (NSF) and the Regents of the University of California was signed on June 24, 1966. This contract initiated the first phase of the DSDP, which was based in Scripps Institution of Oceanography at the University of California, San Diego. Global Marine, Inc. conducted the drilling operations. The Levingston Shipbuilding Company laid the keel of the Glomar Challenger on October 18, 1967, in Orange, Texas.[1] It sailed down the Sabine River to the Gulf of Mexico, and after a period of testing, DSDP accepted the ship on August 11, 1968.[2]

Through contracts with Joint Oceanographic Institutions (JOI), NSF supported the scientific advisory structure for the project and funded pre-drilling geophysical site surveys. Scientific planning was conducted under the auspices of the Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES). The JOIDES advisory group consisted of 250 distinguished scientists from academic institutions, government agencies, and private industry from all over the world. Over the next 30 months, the second phase consisted of drilling and coring in the Atlantic, Pacific, and Indian Ocean as well as the Mediterranean and Red Sea. Technical and scientific reports followed during the period. The second phase of DSDP ended on August 11, 1972.[3]

The success of the Glomar Challenger was almost immediate. On one of the sites with a water depth of 1,067 m (3,500 ft), core samples revealed the existence of salt domes. Oil companies received samples after an agreement to publish their analysis. The potential of oil beneath deep ocean salt domes remains an important avenue for commercial development today.[4][2]

As for the purpose of the scientific exploration, one of the most important discoveries was made when the crew drilled 17 holes at 10 different locations along an oceanic ridge between South America and Africa. The retrieved core samples provided strong proof for continental drift and seafloor renewal at rift zones.[5] This confirmation of Alfred Wegener's theory of continental drift strengthened the proposal of a single, ancient land mass, which is called Pangaea. The samples gave further evidence to support the plate tectonics theory, which at the time attempted to explain the formation of mountain ranges, earthquakes, and oceanic trenches.[6] Another discovery was how youthful the ocean floor is in comparison to Earth's geologic history. After analysis of samples, scientists concluded that the ocean floor is probably no older than 200 million years.[7][2] This is in comparison with the 4.5 billion-year age of the Earth.

The International Phase of Ocean Drilling (IPOD) began in 1975 with the Federal Republic of Germany, Japan, the United Kingdom, the Soviet Union, and France joining the United States in field work aboard the Glomar Challenger and in post-cruise scientific research.[8] The Glomar Challenger docked for the last time with DSDP in November 1983.[9] Parts of the ship, such as its dynamic positioning system, engine telegraph, and thruster console, are stored at the Smithsonian Institution in Washington, D.C. With the advent of larger and more advanced drilling ships, the JOIDES Resolution replaced the Glomar Challenger in January 1985. The new program, called the Ocean Drilling Program (ODP), continued exploration from 1985 to 2003, at which point it was replaced by the Integrated Ocean Drilling Program (IODP).[2]

Coring operations

Although itself a remarkable engineering accomplishment, the Glomar Challenger saw many advances in deep-ocean drilling. One problem solved involved the replacement of worn drill bits.[1] A length of pipe suspended from the ship down to the bottom of the sea might have been as long as 20,483 ft (6,243 m). The maximum depth penetrated through the ocean bottom could have been as great as 4,262 ft (1299 m). To replace the bit, the drill string must be raised, a new bit attached, and the string remade down to the bottom. However, the crew had to thread this string back into the same drill hole. The technique for this formidable task was accomplished on June 14, 1970, in the Atlantic Ocean in 10,000 ft (3048 m) of water off the coast of New York. This re-entry was accomplished with the use of sonar scanning equipment and a re-entry cone that had a diameter of 16 ft (4.88 m) and height of 14 ft (4.27 m).[1]

One major technological advance was the extended use of the holes after drilling.[10] Geophysical and geochemical measurements were made during and after drilling, and occasionally long-term seismic monitoring devices were installed in the holes. This extended understanding of the dynamic processes involved in plate tectonics. Another technological advance involved the introduction of the hydraulic piston corer (HPC[11]) in 1979, which permitted the recovery of virtually undisturbed cores of sediment.[12] This greatly enhanced the ability of scientists to study ancient ocean environments.

From August 11, 1968, to November 11, 1983, the Glomar Challenger achieved the following accomplishments:

Total distance penetrated below the seafloor 325,548 meters
Total interval cored 170,043 meters
Total core recovered and stored 97,056 meters
Overall core recovery 57%
Number of cores recovered 19,119
Number of sites investigated 624
Number of expeditions completed 96
Deepest penetration beneath the ocean floor 1,741 meters
Maximum penetration into basaltic crust 1,080 meters
Deepest water 7,044 meters
Total distance traveled 375,632 nautical miles (695,670 km)

Core samples, publications, and data[10]

The ship retrieved core samples in 30 ft (9.1 m) long cores with a diameter of 2.5 in (6.4 cm). These cores are currently stored at three repositories in the US, Germany, and Japan. One half of each core is called the archive half and is preserved for future use. The working half of each core is used to provide samples for ongoing scientific research.

The scientific results were published as the "Initial Reports of the Deep Sea Drilling Project", which contains the results of studies of the recovered core material and the associated geophysical information from the expeditions from 1968 to 1983.[13] These reports describe the core materials and scientific data obtained at sea and in shore-based laboratories post-cruise. These volumes were originally prepared for NSF under contract by the University of California, Scripps Institution of Oceanography. In 2007, the printed books were scanned and prepared for electronic presentation by the Texas A&M University College of Geosciences.[13]

See also

References

  1. ^ a b c "Ocean Drilling Program: Glomar Challenger drillship". www-odp.tamu.edu.
  2. ^ a b c d "About DSDP". Deep Sea Drilling Project.
  3. ^ Cornford, Chris. "19. Organic Petrography of Lower Cretaceous Shales at DSDP Leg 47B Site 398, Vigo Seamount, Eastern North Atlantic" (PDF). DSDP Volume XLVII Part 2. Deep Sea Drilling Project. pp. 523–527. doi:10.2973/dsdp.proc.47-2.119.1979. Archived (PDF) from the original on July 20, 2018. Retrieved August 3, 2019.
  4. ^ "Initial Reports of the Deep Sea Drilling Project, Volume XV" (PDF). Scripps Institution of Oceanography. Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES) / National Ocean Sediment Coring Program, National Science Foundation. June 1972. LCCN 74-603338. Retrieved August 3, 2019.
  5. ^ http://www.deepseadrilling.org/64/volume/dsdp64pt1_02.pdf
  6. ^ "Archived copy". Archived from the original on 2010-02-27. Retrieved 2009-12-10.CS1 maint: archived copy as title (link)
  7. ^ http://www.deepseadrilling.org/42_1/volume/dsdp42pt1_49.pdf
  8. ^ Heise, Elizabeth A. (1993). "Stone Soup: Acronyms and Abbreviations Used in the Ocean Drilling Program" (PDF). Technical Note No. 13. Ocean Drilling Program, Texas A&M University. Retrieved August 3, 2019.
  9. ^ Glomar Challenger
  10. ^ a b "DSDP Phase: Glomar Challenger". IODP Texas. A&M University.
  11. ^ Chaney, Ronald C.; Almagor, Gideon (2015). Seafloor Processes and Geotechnology. CRC Press. p. 142. ISBN 9781482207415. Retrieved 2016-08-24. As part of the Deep Sea Drilling Project, a hydraulic piston corer (HPC) was developed which can be used with motion-uncompensated drill pipe [...].
  12. ^ "Archived copy". Archived from the original on 2011-07-27. Retrieved 2009-12-10.CS1 maint: archived copy as title (link)
  13. ^ a b "Deep Sea Drilling Project Reports and Publications". Deep Sea Drilling Project.

External links

Alan Cheetham

Alan H. Cheetham is a paleobiologist and retired senior scientist and curator of invertebrate paleontology at the Smithsonian Institution's National Museum of Natural History.

Born in El Paso, Texas, January 30, 1928, Cheetham grew up in Taos, New Mexico, received B.S. (New Mexico Institute of Mining and Technology, 1950) and M.S. (Louisiana State University, 1952) degrees in geology, and, under the guidance of Norman D. Newell, obtained his Ph.D. in paleontology from Columbia University in 1959. Until joining the Smithsonian in 1966, Cheetham was a member of the geology faculty at Louisiana State University; during his tenure there, he was also a visiting postdoctoral fellow at the Natural History Museum in London (1961) and a guest professor at the University of Stockholm, Sweden (1964). He retired from the Smithsonian in 2001 and resides in Santa Fe, New Mexico.

Much of his research includes testing evolutionary models in the fossil record, particularly the theory of punctuated equilibrium. His research is focused on the systematics and morphometrics of late Mesozoic and Cenozoic bryozoans found in deposits located in the Caribbean, especially the Dominican Republic, Panama, Costa Rica, and Venezuela, and the Gulf coast of the United States, particularly Florida, Alabama, and Mississippi. He has also worked extensively on Cenozoic bryozoans in England and southern Scandinavia and was a contributor to the Deep Sea Drilling Project on Cenozoic bryozoans recovered from the Atlantic and Pacific oceans. In April 1997 Cheetham was awarded the Raymond C. Moore Medal for Excellence in Paleontology by the Society for Sedimentary Geology. In November 2001 he received the Paleontological Society Medal; he was, during the same year, honored with a festschrift titled Evolutionary Patterns, edited by Jeremy Jackson, Scott Lidgard, and Frank McKinney.He is married to the former Marjorie Rogers; they have four children and two grandchildren.

Back-arc basin

Back-arc basins are geologic basins, submarine features associated with island arcs and subduction zones. They are found at some convergent plate boundaries, presently concentrated in the western Pacific Ocean. Most of them result from tensional forces caused by oceanic trench rollback (the oceanic trench is wandering in the seafloor direction) and the collapse of the edge of the continent. The arc crust is under extension or rifting as a result of the sinking of the subducting slab. Back-arc basins were initially a surprising result for plate tectonics theorists, who expected convergent boundaries to be zones of compression, rather than major extension. However, they are now recognized as consistent with this model in explaining how the interior of Earth loses heat.

Bruce P. Luyendyk

Bruce Peter Luyendyk (born 1943 in Freeport, New York) is an American geophysicist and oceanographer, currently professor emeritus of marine geophysics at the University of California, Santa Barbara. His work spans marine geology of the major ocean basins, the tectonics of southern California, marine hydrocarbon seeps, and the tectonics and paleoclimate of Antarctica. His research includes tectonic rotations of the California Transverse Ranges, participation in the discovery of deep-sea hydrothermal vents, quantitative studies of marine hydrocarbon seeps, and geologic exploration of the Ford Ranges in Marie Byrd Land, Antarctica.

Antarctica's Mount Luyendyk is named in honor of his research in the area.

Chikyū

Chikyū (ちきゅう) is a Japanese scientific drilling ship built for the Integrated Ocean Drilling Program (IODP). The vessel is designed to ultimately drill seven kilometres beneath the seabed, where the Earth's crust is much thinner, and into the Earth's mantle, 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 (which reached 12 kilometres (7.5 mi) 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.

DSDP 367

The DSDP 367 was an area that was drilled as part of the Deep Sea Drilling Project that took place below the Cape Verde Basin.

DSDP 368

The DSDP 368 was an area that was drilled as part of the Deep Sea Drilling Project that took place below the Cape Verde Rise.

Dorothy Jung Echols

Dorothy Jung Echols (9 September 1916 – 4 February 1997) was a prominent figure in geology in her time, making contributions in the petroleum industry and later teaching as a professor in the department of Earth and Planetary Sciences at Washington University in St. Louis. Echols received her Bachelor of Arts degree in geology from New York University in 1936, and later went on to received her Master's in geology from Columbia University in 1938. In 1982, Echols received the Neil A. Miner Award from the National Association of Geology Teachers which is awarded to exceptional individuals that promote interest in earth sciences.

Glomar Challenger

Glomar Challenger was a deep sea research and scientific drilling vessel for oceanography and marine geology studies. The drillship was designed by Global Marine Inc. (now Transocean Inc.) specifically for a long term contract with the American National Science Foundation and University of California Scripps Institution of Oceanography and built by Levingston Shipbuilding Company in Orange, Texas. Launched on March 23, 1968, the vessel was owned and operated by the Global Marine Inc. corporation. Glomar Challenger was given its name as a tribute to the accomplishments of the oceanographic survey vessel HMS Challenger. Glomar is a truncation of Global Marine.

Horizon Guyot

Horizon Guyot is a presumably Cretaceous guyot (tablemount) in the Mid-Pacific Mountains, Pacific Ocean. It is an elongated ridge, over 300 kilometres (190 mi) long and 4.3 kilometres (2.7 mi) high, that stretches in a northeast-southwest direction and has two flat tops; it rises to a minimum depth of 1,443 metres (4,730 ft). The Mid-Pacific Mountains lie west of Hawaii and northeast of the Line Islands.

It was probably formed by a hotspot, but the evidence is conflicting. Volcanic activity occurred during the Turonian-Cenomanian eras 100.5–89.8 million years ago and another stage has been dated to have occurred 88–82 million years ago. Between these volcanic episodes, carbonate deposition from lagoonal and reefal environments set in and formed limestone. Volcanic islands developed on Horizon Guyot as well and were colonised by plants.

Horizon Guyot became a seamount during the Coniacian-Campanian period. Since then, pelagic ooze has accumulated on the seamount, forming a thick layer that is further modified by ocean currents and by various organisms that live on the seamount; sediments also underwent landsliding. Ferromanganese crusts were deposited on exposed rocks.

International Ocean Discovery Program

The International Ocean Discovery Program (IODP) is an international marine research collaboration dedicated to advancing scientific understanding of the Earth through drilling, coring, and monitoring the subseafloor. The research enabled by IODP samples and data improves scientific understanding of changing climate and ocean conditions, the origins of ancient life, risks posed by geohazards, and the structure and processes of Earth's tectonic plates and uppermost mantle. IODP began in 2013 and builds on the research of four previous scientific ocean drilling programs: Project Mohole, Deep Sea Drilling Project, Ocean Drilling Program, and Integrated Ocean Drilling Program. Together, these programs represent the longest running and most successful international Earth science collaboration.

Ita Mai Tai

Ita Mai Tai is a Cretaceous-early Cenozoic seamount northwest of the Marshall Islands and north of Micronesia. One among a number of seamounts in the Pacific Ocean, it is part of the Magellan Seamounts which may have a hotspot origin although Ita Mai Tai itself may not have formed on a hotspot.

The seamount is formed by volcanic rocks which form two adjacent volcanic centres that erupted between the Aptian-Albian and possibly as late as the Pliocene. Reef systems developed on the seamount after its formation and led to the deposition of limestones. Especially during the Oligocene the seamount subsided and lies now at 1,402 metres (4,600 ft) depth below sea level. Ferromanganese crusts as well as pelagic oozes were deposited on the submerged rocks.

J. Lamar Worzel

J. Lamar (Joe) Worzel (February 21, 1919 – December 26, 2008) was an American geophysicist known for his important contributions to underwater acoustics, underwater photography, and gravity measurements at sea.

Meiji Seamount

Meiji Seamount, named after Emperor Meiji, the 122nd Emperor of Japan, is the oldest seamount in the Hawaiian-Emperor seamount chain, with an estimated age of 82 million years. It lies at the northernmost end of the chain, and is perched at the outer slope of the Kuril-Kamchatka Trench. Like the rest of the Emperor seamounts, it was formed by the Hawaii hotspot volcanism, grew to become an island, and has since subsided to below sea level, all while being carried first north and now northwest by the motion of the Pacific Plate. Meiji Seamount is thus an example of a particular type of seamount known as a guyot, and some publications refer to it as Meiji Guyot.

Meiji Seamount will eventually be destroyed by subduction into the Kuril-Kamchatka Trench where it is carried by the ongoing plate motion, although this will not fully occur for several million more years if the current rate of motion is maintained. Although Meiji is the oldest extant seamount in the Hawaii-Emperor chain, the question of whether there were older seamounts in the chain which have already been subducted into the trench remains open, and is the subject of ongoing scientific research.

The Deep Sea Drilling Project (DSDP) Leg 19, Hole 192A, recovered 13 m (43 ft) of pillow lava from near the summit of Meiji. The lavas were initially classified as alkali basalts on the basis of their mineralogy, but subsequent microprobe analyses of glass and pyroxene suggested that they are tholeiitic in origin. At least five flows were found.

Middle America Trench

The Middle America Trench is a major subduction zone, an oceanic trench in the eastern Pacific Ocean off the southwestern coast of Middle America, stretching from central Mexico to Costa Rica. The trench is 1,700 miles (2,750 km) long and is 21,880 feet (6,669 m) at its deepest point.

The trench is the boundary between the Rivera, Cocos, and Nazca plates on one side and the North American and Caribbean plates on the other. It is the 18th-deepest trench in the world. Many large earthquakes have occurred in the area of the Middle America Trench.

Ocean Drilling Program

The Ocean Drilling Program (ODP) was a multinational effort to explore and study the composition and structure of the Earth's oceanic basins. ODP, which began in 1985, was the successor to the Deep Sea Drilling Project initiated in 1968 by the United States. ODP was an international effort with contributions of Australia, Germany, France, Japan, the United Kingdom and the ESF Consortium for Ocean Drilling (ECOD) including 12 further countries. The program used the drillship JOIDES Resolution on 110 expeditions (legs) to collect about 2000 deep sea cores from major geological features located in the ocean basins of the world. Drilling discoveries led to further questions and hypotheses, as well as to new disciplines in earth sciences such as the field of paleoceanography. In 2004 ODP transformed into the Integrated Ocean Drilling Program (IODP).

Ojin Seamount

Ōjin Seamount, also called Ōjin Guyot, named after Emperor Ōjin, 15th Emperor of Japan, is a guyot of the Hawaiian-Emperor seamount chain in the Pacific Ocean. It erupted 55 million years ago.

Project Mohole

Project Mohole was an attempt in the early 1960s to drill through the Earth's crust to obtain samples of the Mohorovičić discontinuity, or Moho, the boundary between the Earth's crust and mantle. The project was to provide an Earth Science complement to the high-profile Space Race. While such a project was not feasible on land, drilling in the open ocean would be more feasible, because the mantle is much closer to the sea floor. The project was initially led by a group of scientists called the American Miscellaneous Society with funding from the National Science Foundation. The project suffered from political and scientific battles, mismanagement, and cost over-runs, and the U.S. House of Representatives discontinued funding for the project in 1966. By then a program of sediment drilling had branched from Project Mohole to become the Deep Sea Drilling Project of the National Science Foundation.

Ross Sea

The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about 200 miles (320 km) from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of 637,000 square kilometres (246,000 sq mi).The circulation of the Ross Sea is dominated by a wind-driven ocean gyre and the flow is strongly influenced by three submarine ridges that run from southwest to northeast. The circumpolar deep water current is a relatively warm, salty and nutrient-rich water mass that flows onto the continental shelf at certain locations. The Ross Sea is covered with ice for most of the year.

The nutrient-laden water supports an abundance of plankton and this encourages a rich marine fauna. At least ten mammal species, six bird species and 95 fish species are found here, as well as many invertebrates, and the sea remains relatively unaffected by human activities. New Zealand has claimed that the sea comes under its jurisdiction as part of the Ross Dependency. Marine biologists consider the sea to have a high level of biological diversity and it is the site of much scientific research. It is also the focus of some environmentalist groups who have campaigned to have the area proclaimed as a world marine reserve. In 2016 an international agreement established the region as a marine park.

Yomei Seamount

Yomei Seamount is a seamount of the Hawaiian-Emperor seamount chain in the northern Pacific Ocean.

Its eruption ages are unknown, but the seamounts on either side are in the 56.2 to 59.6 million range during the Paleogene Period.

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