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24-650: Glomar Challenger was built to help Harry Hess with the theory of Seafloor Spreading by taking rock samples confirming that the farther from the Mid-ocean ridge , the older the rock was. Starting from August 1968, the ship was embarked on a 15-year-long scientific expedition, the Deep Sea Drilling Program , criss-crossing the Mid-Atlantic Ridge between South America and Africa and drilling core samples at specific locations. When

48-580: A Bachelor of Science degree in geology. Hess failed his first time taking mineralogy at Yale and was told he had no future in the field. Despite this, he continued with his degree and was teaching geology at Princeton when World War II was declared. He spent two years as an exploration geologist in Northern Rhodesia . In 1934 he married Annette Burns. Harry Hess taught for one year (1932–1933) at Rutgers University in New Jersey and spent

72-453: A way. His discoveries could be explained only with the development of the theory of plate tectonics in the 1950s. Vening Meinesz measured the gravity field of the Earth with his pendulum apparatus on board several submarines. The following expeditions are described in his publications, Gravity Expeditions at Sea : Vol 1: 1923–1930 Vol II: 1923–1933 Vol III: 1934–1939 Vening Meinesz

96-617: A year as a research associate at the Geophysical Laboratory of Washington, D. C. , before joining the faculty of Princeton University in 1934. Hess remained at Princeton for the rest of his career and served as Geology Department Chairman from 1950 to 1966. He was a visiting professor at the University of Cape Town , South Africa (1949–1950), and the University of Cambridge , England (1965). Hess accompanied Dr. Felix Vening Meinesz of Utrecht University on board

120-754: The American Philosophical Society in 1960. He was president of The Geological Society of America in 1963 and received their Penrose Medal in 1966. In 1968, he was elected to the American Academy of Arts and Sciences . Hess died from a heart attack in Woods Hole, Massachusetts , on August 25, 1969, while chairing a meeting of the Space Science Board of the National Academy of Sciences . He

144-988: The Delft University of Technology as well. He was awarded the Howard N. Potts Medal in 1936, and several other major geology prizes in later years. In World War II , Vening Meinesz was involved in the Dutch resistance. After the war he could take up his tasks as a professor again. From 1945 to 1951 he was the director of the KNMI. From 1948 to 1951, Vening Meinesz was President of the International Union of Geodesy and Geophysics . He retired in 1957, and died in Amersfoort in 1966. The vast amounts of data that his expeditions yielded were analyzed and discussed together with other leading Dutch Earth scientists of

168-609: The Marianas , Philippines , and Iwo Jima , continuously using his ship's echo sounder . This unplanned wartime scientific surveying enabled Hess to collect ocean floor profiles across the North Pacific Ocean , resulting in the discovery of flat-topped submarine volcanoes, which he termed guyots , after the 19th-century geographer Arnold Henry Guyot . After the war, he remained in the Naval Reserve , rising to

192-617: The Messinian Salinity Crisis theory. Harry Hammond Hess Harry Hammond Hess (May 24, 1906 – August 25, 1969) was an American geologist and a United States Navy officer in World War II who is considered one of the "founding fathers" of the unifying theory of plate tectonics . He published theories on sea floor spreading , specifically on relationships between island arcs , seafloor gravity anomalies , and serpentinized peridotite , suggesting that

216-488: The Netherlands, for which a network of 51 monitoring stations was created. This became a success, which encouraged him to do measurements at sea. A perfected gravimeter, hanging in a "swing", was designed. The experiment was successful. Now measuring gravity at sea had become possible. Between 1923 and 1929, the tall (over 2 metres) Vening Meinesz embarked in small submarines for some uncomfortable expeditions. His goal

240-570: The North Pacific Ocean after Marie Tharp and Bruce Heezen (1953, Lamont Group ) discovered the Great Global Rift , running along the Mid-Atlantic Ridge . Seafloor spreading , as the process was later named, helped establish Alfred Wegener 's earlier (but generally dismissed at the time) concept of continental drift as scientifically respectable. This triggered a revolution in the earth sciences. Hess's report

264-541: The US Navy submarine USS S-48 to assist with the second U.S. expedition to obtain gravity measurements at sea. The expedition used a gravimeter , or gravity meter, designed by Meinesz. The submarine traveled a route from Guantanamo, Cuba , to Key West, Florida , and return to Guantanamo through the Bahamas and Turks and Caicos region from 5 February through 25 March 1932. The description of operations and results of

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288-563: The age of the samples was determined by paleontologic and isotopic dating studies, this provided conclusive evidence for the seafloor spreading hypothesis, and, consequently, for plate tectonics . During 1970, when doing research in the Mediterranean Sea while supervised by Kenneth Hsu , geologists aboard the vessel brought up drill cores containing gypsum , anhydrite , rock salt, and various other evaporite minerals that often form from drying of brine or seawater. These were

312-618: The convection in the Earth's mantle is the driving force behind this process. Harry Hammond Hess was born on May 24, 1906, in New York City to Julian S. Hess, a member of the New York Stock Exchange , and Elizabeth Engel Hess. He attended Asbury Park High School in Asbury Park, New Jersey . In 1923, he entered Yale University , where he intended to study electrical engineering but ended up graduating with

336-804: The expedition were published by the U.S. Navy Hydrographic Office in The Navy-Princeton gravity expedition to the West Indies in 1932 . Hess joined the United States Navy during World War II, becoming captain of the USS Cape Johnson , an attack transport ship equipped with a new technology: sonar . This command would later prove to be key in Hess's development of his theory of sea floor spreading . Hess carefully tracked his travel routes to Pacific Ocean landings on

360-456: The first solid evidence for the ancient desiccation of the Mediterranean Sea , the Messinian salinity crisis . After being operated for fifteen years, Glomar Challenger' s active duty was ended during November 1983 and she was later scrapped. Her successor, JOIDES Resolution , was launched during 1985. Glomar Challenger was a success in collecting rock samples and helped to confirm

384-462: The principle of isostasy . Vening Meinesz was especially intrigued by the oceanic trenches. The coexistence of active volcanism , large negative gravity anomalies and the sudden difference in terrain elevation could only be explained by assuming the Earth's crust was somehow pushed together at these places. As a geophysicist, he was prejudiced that the crust was too rigid to deform at that scale in such

408-485: The rank of rear admiral . In 1960, Hess made his single most important contribution, which is regarded as part of the major advance in geologic science of the 20th century. In a widely circulated report to the Office of Naval Research , he advanced the theory, now generally accepted, that the Earth's crust moved laterally away from long, volcanically active oceanic ridges . He only understood his ocean floor profiles across

432-518: The same size hanging in a frame but moving in opposite phases. With mirrors and lightbeams the difference in amplitude of the two pendula is captured on a film. Vening Meinesz had discovered that horizontal accelerations (as by waves on a boat) had no influence on the difference in amplitude between the two pendula. The recorded difference then is the amplitude of a theoretical, undisturbed pendulum. Now it became possible to measure gravity more accurately. Vening Meinesz started with measuring gravity all over

456-474: The time, J.H.F. Umbgrove , B.G. Escher and Ph.H. Kuenen . The results were published in 1948. An important result was the discovery of elongated belts of negative gravity anomalies along the oceanic trenches , along with a large circular anomaly that became known as the Indian Ocean Geoid Low . The mean gravity force appeared to be the same on land and at sea, which was in agreement with

480-501: Was a Dutch geophysicist and geodesist . He is known for his invention of a precise method for measuring gravity ( gravimetry ). Thanks to his invention, it became possible to measure gravity at sea, which led him to the discovery of gravity anomalies above the ocean floor. He later attributed these anomalies to continental drift . He was a Fellow of the Royal Society . Vening Meinesz's father, Sjoerd Anne Vening Meinesz,

504-606: Was buried at Arlington National Cemetery and was posthumously awarded the National Aeronautics and Space Administration's Distinguished Public Service Award. The American Geophysical Union established the Harry H. Hess medal in his memory in 1984 to "honor outstanding achievements in research of the constitution and evolution of Earth and sister planets." Source: Felix Andries Vening Meinesz Felix Andries Vening Meinesz (30 July 1887 – 10 August 1966)

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528-550: Was formally published in his History of Ocean Basins (1962), which for a time was the single most referenced work in solid-earth geophysics . Hess was also involved in many other scientific endeavours, including the Mohole project (1957–1966), an investigation onto the feasibility and techniques of deep sea drilling . Hess was elected to the United States National Academy of Sciences in 1952 and

552-633: Was mayor, first of Rotterdam , then of Amsterdam . Felix was born in The Hague and grew up in a protected environment. In 1910 he graduated in civil engineering in Delft . The same year he started working for the Dutch gravity survey. In 1915 he wrote his dissertation on the defects of the gravimeters used at that time. Vening Meinesz then designed a new gravimeter, which the KNMI (Royal Dutch Meteorological Institute) built. The apparatus has two pendula of

576-579: Was to establish the exact shape of the geoid and the Earth . When his expedition with the submarine HNLMS K XVIII was made into a movie in 1935, Vening Meinesz became a hero of the Dutch cinema public. Besides, his research was in the international scientific spotlight. In 1927 he became a member of the Royal Netherlands Academy of Arts and Sciences . In 1927 he became a part-time professor in geodesy, cartography and geophysics at Utrecht University , and in 1937 he became professor at

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