Harry Hammond Hess (May 24, 1906 – August 25, 1969) was an American

geologist A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...

and a

United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...

officer in

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

who is considered one of the "founding fathers" of the unifying theory of

plate tectonics Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...

. He is best known for his theories on

sea floor spreading Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. History of study Earlier theories by Alfred Wegener an ...

, specifically work on relationships between

island arc Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle alon ...

s, seafloor gravity anomalies, and serpentinized

peridotite Peridotite ( ) is a dense, coarse-grained igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium (Mg2+), reflecting the high prop ...

, suggesting that the convection of the Earth's mantle was the driving force behind this process.

Early life and education

Harry Hammond Hess was born on May 24, 1906, in

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

to Julian S. Hess, a member of the

New York Stock Exchange The New York Stock Exchange (NYSE, nicknamed "The Big Board") is an American stock exchange in the Financial District of Lower Manhattan in New York City. It is by far the world's largest stock exchange by market capitalization of its listed c ...

, and Elizabeth Engel Hess. He attended

Asbury Park High School Asbury Park High School is a comprehensive high school, comprehensive, four-year community state school, public Secondary education in the United States, high school serving students in ninth grade, ninth through twelfth grades. It is in a land ...

Asbury Park, New Jersey Asbury Park () is a beachfront city located on the Jersey Shore in Monmouth County in the U.S. state of New Jersey. It is part of the New York metropolitan area. As of the 2020 U.S. census, the city's population was 15,188

. In 1923, he entered

Yale University Yale University is a private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and among the most prestigious in the wo ...

, where he intended to study

electrical engineering Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...

but ended up graduating with a

Bachelor of Science A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University of ...

degree in geology. He spent two years as an exploration geologist in

Northern Rhodesia Northern Rhodesia was a British protectorate in southern Africa, south central Africa, now the independent country of Zambia. It was formed in 1911 by Amalgamation (politics), amalgamating the two earlier protectorates of Barotziland-North-West ...

. In 1934 he married Annette Burns.

Teaching career

Harry Hess taught for one year (1932–1933) at

Rutgers University Rutgers University (; RU), officially Rutgers, The State University of New Jersey, is a Public university, public land-grant research university consisting of four campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's ...

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

and spent a year as a research associate at the Geophysical Laboratory of

Washington, D. C. ) , image_skyline = , image_caption = Clockwise from top left: the Washington Monument and Lincoln Memorial on the National Mall, United States Capitol, Logan Circle, Jefferson Memorial, White House, Adams Morgan, Na ...

, before joining the faculty of

Princeton University Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...

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 The University of Cape Town (UCT) ( af, Universiteit van Kaapstad, xh, Yunibesithi ya yaseKapa) is a public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university statu ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

(1949–1950), and the

University of Cambridge , mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Schola ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

(1965).

The Navy-Princeton gravity expedition to the West Indies in 1932

Hess accompanied Dr. Felix Vening Meinesz of

Utrecht University Utrecht University (UU; nl, Universiteit Utrecht, formerly ''Rijksuniversiteit Utrecht'') is a public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2018, it had an enrollme ...

on board 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 Gravimetry is the measurement of the strength of a gravitational field. Gravimetry may be used when either the magnitude of a gravitational field or the properties of matter responsible for its creation are of interest. Units of measurement Gr ...

, or gravity meter, designed by Meinesz. The submarine traveled a route from Guantanamo, Cuba, to

Key West, Florida Key West ( es, Cayo Hueso) is an island in the Straits of Florida, within the U.S. state of Florida. Together with all or parts of the separate islands of Sigsbee Park, Dredgers Key, Fleming Key, Sunset Key, and the northern part of Stock Isla ...

, and return to Guantanamo through the

Bahamas The Bahamas (), officially the Commonwealth of The Bahamas, is an island country within the Lucayan Archipelago of the West Indies in the Atlantic Ocean, North Atlantic. It takes up 97% of the Lucayan Archipelago's land area and is home to ...

and

Turks and Caicos The Turks and Caicos Islands (abbreviated TCI; and ) are a British Overseas Territory consisting of the larger Caicos Islands and smaller Turks Islands, two groups of tropical islands in the Lucayan Archipelago of the Atlantic Ocean and n ...

region from 5 February through 25 March 1932. The description of operations and results of the expedition were published by the U.S. Navy Hydrographic Office in ''The Navy-Princeton gravity expedition to the West Indies in 1932''.

Military and war career

Hess joined the

during World War II, becoming

captain Captain is a title, an appellative for the commanding officer of a military unit; the supreme leader of a navy ship, merchant ship, aeroplane, spacecraft, or other vessel; or the commander of a port, fire or police department, election precinct, e ...

of the USS ''Cape Johnson'', an attack transport ship equipped with a new technology:

sonar Sonar (sound navigation and ranging or sonic navigation and ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigation, navigate, measure distances (ranging), communicate with or detect o ...

. This command would later prove to be key in Hess's development of his theory of

. Hess carefully tracked his travel routes to

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

landings on the

Marianas The Mariana Islands (; also the Marianas; in Chamorro: ''Manislan Mariånas'') are a crescent-shaped archipelago comprising the summits of fifteen longitudinally oriented, mostly dormant volcanic mountains in the northwestern Pacific Ocean, betw ...

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, and

Iwo Jima Iwo Jima (, also ), known in Japan as , is one of the Japanese Volcano Islands and lies south of the Bonin Islands. Together with other islands, they form the Ogasawara Archipelago. The highest point of Iwo Jima is Mount Suribachi at high. ...

, continuously using his ship's

echo sounder Echo sounding or depth sounding is the use of sonar for ranging, normally to determine the depth of water (bathymetry). It involves transmitting acoustic waves into water and recording the time interval between emission and return of a pulse; ...

. This unplanned wartime scientific surveying enabled Hess to collect ocean floor profiles across the North

, resulting in the discovery of flat-topped submarine volcanoes, which he termed

guyot In marine geology, a guyot (pronounced ), also known as a tablemount, is an isolated underwater volcanic mountain ( seamount) with a flat top more than below the surface of the sea. The diameters of these flat summits can exceed .Arnold Henry Guyot Arnold Henry Guyot ( ) (September 28, 1807February 8, 1884) was a Swiss-American geologist and geographer. Early life Guyot was born on September 28, 1807, at Boudevilliers, near Neuchâtel, Switzerland. He was educated at Chaux-de-Fonds, th ...

. After the war, he remained in the Naval Reserve, rising to the rank of

rear admiral Rear admiral is a senior naval flag officer rank, equivalent to a major general and air vice marshal and above that of a commodore and captain, but below that of a vice admiral. It is regarded as a two star "admiral" rank. It is often regarde ...

Scientific discoveries

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 The Office of Naval Research (ONR) is an organization within the United States Department of the Navy responsible for the science and technology programs of the U.S. Navy and Marine Corps. Established by Congress in 1946, its mission is to plan ...

, he advanced the theory, now generally accepted, that the Earth's crust moved laterally away from long, volcanically active

oceanic ridges A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a Diverge ...

. He only understood his ocean floor profiles across the North Pacific Ocean after

Marie Tharp Marie Tharp (July 30, 1920 – August 23, 2006) was an American geologist and oceanographic cartographer. In the 1950s, she collaborated with geologist Bruce Heezen to produce the first scientific map of the Atlantic Ocean floor. Her cartograp ...

and

Bruce Heezen Bruce Charles Heezen (; April 11, 1924 – June 21, 1977) was an American geologist. He worked with oceanographic cartographer Marie Tharp at Columbia University to map the Mid-Atlantic Ridge in the 1950s. Biography Heezen was born in Vinton, Io ...

(1953, Lamont Group) discovered the

Great Global Rift A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a diver ...

, running along the

Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North Ame ...

. ''

Seafloor spreading Seafloor spreading or Seafloor spread is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. History of study Earlier theories by Alfred Wegener an ...

'', as the process was later named, helped establish

Alfred Wegener Alfred Lothar Wegener (; ; 1 November 1880 – November 1930) was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher. During his lifetime he was primarily known for his achievements in meteorology and ...

's earlier (but generally dismissed at the time) concept of

continental drift Continental drift is the hypothesis that the Earth's continents have moved over geologic time relative to each other, thus appearing to have "drifted" across the ocean bed. The idea of continental drift has been subsumed into the science of pla ...

as scientifically respectable. This triggered a revolution in the earth sciences. Hess's report was formally published in his
History of Ocean Basins
' (1962), which for a time was the single most referenced work in solid-earth

geophysics Geophysics () is a subject of natural science concerned with the physical processes and physical properties of the Earth and its surrounding space environment, and the use of quantitative methods for their analysis. The term ''geophysics'' som ...

. 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.

Accolades and affiliations

Hess was elected to the United States

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

in 1952 and the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 1960. He was president of

The Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitchco ...

in 1963 and received their

Penrose Medal The Penrose Medal was created in 1925 by R.A.F. Penrose, Jr., as the top prize awarded by the Geological Society of America. Originally created as the Geological Society of America Medal it was soon renamed the Penrose Medal by popular assent of t ...

in 1966. In 1968, he was elected to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...

Death

Hess died from a

heart attack A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may tr ...

Woods Hole, Massachusetts Woods Hole is a census-designated place in the town of Falmouth in Barnstable County, Massachusetts, United States. It lies at the extreme southwest corner of Cape Cod, near Martha's Vineyard and the Elizabeth Islands. The population was 781 at ...

, on August 25, 1969, while chairing a meeting of the Space Science Board of the

. He was buried at

Arlington National Cemetery Arlington National Cemetery is one of two national cemeteries run by the United States Army. Nearly 400,000 people are buried in its 639 acres (259 ha) in Arlington, Virginia. There are about 30 funerals conducted on weekdays and 7 held on Sa ...

and was posthumously awarded the National Aeronautics and Space Administration's Distinguished Public Service Award.

The Harry H. Hess Medal

The

American Geophysical Union The American Geophysical Union (AGU) is a 501(c)(3) nonprofit organization of Earth, atmospheric, ocean, hydrologic, space, and planetary scientists and enthusiasts that according to their website includes 130,000 people (not members). AGU's act ...

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."

Past recipients

Source: * 1985 Gerald J. Wasserburg * 1987 Julian R. Goldsmith * 1989 A.G.W. Cameron * 1991

George W. Wetherill George Wetherill (August 12, 1925 Philadelphia, Pennsylvania – July 19, 2006 Washington, DC) was a physicist and geologist and the Director Emeritus of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington, DC, USA. ...

* 1993 Alfred E. Ringwood * 1995

Edward Anders Edward Anders (born June 21, 1926) is a Latvian-born American chemist and emeritus professor of chemistry at the University of Chicago. His major areas of research have included the origin and ages of meteorites, the existence of presolar grain ...

* 1996 Thomas J. Ahrens * 1997 Stanley Robert Hart * 1998

David J. Stevenson David John Stevenson (born 2 September 1948) is a professor of planetary science at Caltech. Originally from New Zealand, he received his Ph.D. from Cornell University in physics, where he proposed a model for the interior of Jupiter. He is well k ...

* 1999 Ikuo Kushiro * 2001 Albrecht Hofmann * 2002 Gerald Schubert * 2003 David L. Kohlstedt * 2004 Adolphe Nicolas * 2005 Sean C. Solomon * 2006

Alexandra Navrotsky Alexandra Navrotsky (born 20 June 1943 in New York City) is a physical chemist in the field of nanogeoscience. She is an elected member of the United States National Academy of Sciences (NAS) and the American Philosophical Society (APS). She w ...

* 2007 Michael John O'Hara * 2008

H. Jay Melosh H. Jay Melosh (June 23, 1947 – September 11, 2020) was an American geophysicist specialising in impact cratering. He earned a degree in physics from Princeton University and a doctoral degree in physics and geology from Caltech in 1972. His P ...

* 2009 Frank M. Richter * 2010 David Walker * 2011 Henry Dick * 2012 Maria T. Zuber * 2013 Bernard Wood * 2014 Donald J. DePaolo * 2015 Claude Jaupart * 2016

Alexander Halliday Sir Alexander Norman Halliday (born 11 August 1952) is a British geochemist, an academic who is the Founding Dean of the Columbia Climate School, and Director of the Earth Institute at Columbia University. He joined the Earth Institute in Apri ...

* 2017

Roberta Rudnick Roberta L. Rudnick (born 1958) is an American earth scientist and professor of geology at the University of California, Santa Barbara. She was elected a member of the National Academy of Sciences in 2010 and was awarded the Dana Medal by the Min ...

* 2018 Timothy L. Grove * 2019 Richard J. Walker * 2020 Donald B. Dingwell

Selected publications

* **Also in: *** *** * * * * * **Also in: *** * *

References

External links

Harry Hess (1906–1969) A Science Odyssey: People and Discoveries
taken from
AGU Harry H. Hess Medal
{{DEFAULTSORT:Hess, Harry American geophysicists Asbury Park High School alumni Tectonicists Scientists from New York City United States Navy rear admirals (upper half) 1906 births 1969 deaths University of Cape Town academics Yale University alumni Burials at Arlington National Cemetery Penrose Medal winners Princeton University faculty Rutgers University faculty Presidents of the Geological Society of America Marine geophysicists Members of the American Philosophical Society