Table of Contents
What are the three main evidence of seafloor spreading theory?
Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.
How proposed the theory of seafloor spreading?
The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960.
What are the 4 evidences for seafloor spreading?
Evidence of Sea Floor Spreading
- Molten material. Hess’s discovery on the warmer temperature near the mid-Atlantic ridge when he began the ocean mapping, led to his evidence about the molten material underneath the ocean.
- Seafloor drill.
- Radiometric age dating and fossil ages.
- Magnetic stripes.
What are the strongest evidence for the seafloor spreading?
When the Earth’s magnetic field reverses, a new stripe, with the new polarity, begins. Such magnetic patterns led to recognition of the occurrence of sea-floor spreading, and they remain some of the strongest evidence for the theory of plate tectonics.
What is the best explanation of seafloor spreading?
The seafloor spreading definition is the geologic process that occurs at the boundary between 2 plates where molten material within the earth pushes its way up, causing the plates to move away from each other. At these divergent boundaries molten material cools and hardens, creating new oceanic crust or seafloor.
What geological features did Harry Hess discover?
Mid Ocean Ridges
Hess discovered that the oceans were shallower in the middle and identified the presence of Mid Ocean Ridges, raised above the surrounding generally flat sea floor (abyssal plain) by as much as 1.5 km.
What geologic feature did Harry Hess discover?
What is the main cause of seafloor spreading?
Sea-floor spreading is what happens at the mid-oceanic ridge where a divergent boundary is causing two plates to move away from one another resulting in spreading of the sea floor. As the plates move apart, new material wells up and cools onto the edge of the plates.
Which of the following is evidence of seafloor spreading?
What is the evidence for sea-floor spreading? Several types of evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
Which geologic features result from seafloor spreading?
The main geographical feature formed by the process of seafloor spreading are mid-ocean ridges. Usually, these submarine mountain ranges have a valley running on their spine which is known as a rift and is about a mile in depth.
What is one piece of evidence 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 evidence supports Hess’s theory of seafloor spreading?
Sea floor continues to spread apart as new crust is added. Processes repeats like a conveyor belt, carrying continents along with them. Evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
What did Harry Hess discover about the ocean floor?
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 discoveries prompted the hypothesis of seafloor spreading?
In 1963, Vine and Matthews tied the discovery of magnetic stripes in the oceanic crust near ridges to Hess’s concept of seafloor spreading. Harry Hess “An essay in Geopoetry” 1960 Contains the Sea Floor Spreading Hypothesis. It had good evidence and reached a wide audience.
What type of rock makes up the seafloor?
Answer and Explanation: Basalt is the type of igneous rock that makes up the ocean floor. In the middle of the Atlantic Ocean is a divergent plate boundary.
What is the strongest evidence for seafloor spreading?
What evidence supports Harry Hess theory?
He used fossil evidence, such as that of tropical plants found on the Arctic island of Spitzbergen. He found large-scale geographic features that matched, like the Appalachian Mountains in the United States and the Scottish Highlands, as well as rock strata in South Africa that matched those in Brazil.
What is the geological process of the ocean?
Scientists now know that the moving seafloor is recycled into Earth’s interior at trenches, a process called subduction. Chains of large volcanoes, called arc volcanoes, form on the outer edges of trenches. The Andes Mountains of South America and the islands of Japan are examples of arc volcanoes.
What igneous rock makes up most of the ocean floor?
Basalt is the type of igneous rock that makes up the ocean floor.
What supports Hess’s theory of seafloor spreading?
Processes repeats like a conveyor belt, carrying continents along with them. Process of Sea-floor Spreading. EVIDENCE FOR SEA-FLOOR SPREADING. Evidence supported Hess’s theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves.
How do scientists prove the seafloor is spreading?
The seafloor’s permanent magnetic signatures showed that new ocean crust was created at the ridge crests and then spread outward in both directions. This seafloor spreading hypothesis had been proposed a few years earlier by Harry Hess, a petrologist at Princeton University, and Robert Dietz, an oceanographer in the US Coast and Geodetic Survey (the federal department that made maps of the oceans and US coastlines).
Did Alfred Wegener proposed the theory of seafloor spreading?
Alfred Wegener produced evidence in 1912 that the continents are in motion, but because he could not explain what forces could move them, geologists rejected his ideas. Almost 50 years later Harry Hess confirmed Wegener’s ideas by using the evidence of seafloor spreading to explain what moved continents. Alfred Wegener, courtesy of the Alfred
What is the major evidence that seafloor spreading?
Molten Material (magma/lava) – scientists have found strange rocks shaped like pillows in the central valley of the ocean ridge.…
What was the hypothesis of the sea-floor spreading?
The seafloor spreading hypothesis was proposed by the American geophysicist Harry H. Hess in 1960 . On the basis of Tharp’s efforts and other new discoveries about the deep-ocean floor, Hess postulated that molten material from Earth’s mantle continuously wells up along the crests of the mid-ocean ridges that wind for nearly 80,000 km (50,000 miles) through all the world’s oceans.