What is Harry Hess known for?
Harry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains, perhaps sunken islands, shape the Pacific floor.
What did Hess suggest was causing the motion of the seafloor?
In this paper, Hess, drawing on Holmes’s model of convective flow in the mantle, suggested that the oceanic ridges were the surface expressions of rising and diverging convective mantle flow, while trenches and Wadati-Benioff zones, with their associated island arcs, marked descending limbs.
What evidence supports the theory of seafloor spreading?
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
What are the two evidence of seafloor spreading?
Harry Hess’s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. This evidence was from the investigations of the molten material, seafloor drilling, radiometric age dating and fossil ages, and the magnetic stripes.
Who proposed the theory of seafloor spreading?
Harry Hess
Harry Hess: One of the Discoverers of Seafloor Spreading.
Which is the first step in the seafloor spreading process?
1. A long crack in the oceanic crust forms at a mid ocean ridge. 2. Molten material rises and erupts along the ridge.
What are different types of seafloor spreading?
There are three types of plate-plate interactions based upon relative motion: convergent, where plates collide, divergent, where plates separate, and transform motion, where plates simply slide past each other.
Why is seafloor spreading important?
Today it refers to the processes creating new oceanic lithosphere where plates move apart. Seafloor spreading replaces the lithosphere destroyed by subduction, and exerts important influences on Earth’s chemical and biological evolution.
What evidence did Harry Hess use to prove sea-floor spreading?
Evidence of Sea Floor Spreading. Harry Hess’s hypothesis about seafloor spreading had collected several pieces of evidence to support the theory. This evidence was from the investigations of the molten material, seafloor drilling, radiometric age dating and fossil ages, and the magnetic stripes.
Abundant evidence supports the major contentions of the seafloor-spreading theory. First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.
Who suggested the theory of seafloor spreading?
Robert S. Dietz, American geophysicist and oceanographer who set forth a theory of seafloor spreading in 1961. Dietz was educated at the University of Illinois (B.S., 1937; M.S., 1939; Ph.D., 1941). After serving as an officer in the U.S. Army Air Corps during World War II, he became a civilian
How do scientists prove the seafloor is spreading?
The magnetism of mid-ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century. Basalt, the once-molten rock that makes up most new oceanic crust, is a fairly magnetic substance, and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s. What they discovered was that the magnetism of the ocean floor around mid-ocean ridges was divided into matching “stripes” on either side of the ridge.