Which is the first step in the sea floor spreading process?
Which is the first step in the seafloor spreading process? A crack forms in oceanic crust.
What are the three steps of seafloor spreading?
Terms in this set (7) Magma cools to rock and hardens. Rock is pushed away as new rock is formed at MOR. Oceanic crust and continental crust meet at the trench. Oceanic crust bends down under the continental crust.
What are the 4 main proofs for seafloor spreading theory?
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.
What is the first step of seafloor spreading a crack forms in oceanic crust molten rock rises up through oceanic crust molten rock solidifies at th?
The process is called sea-floor spreading. Ridges form along cracks (divergent boundaries) in the oceanic crust (Molten rock (magma) rises through these cracks and pushes to both sides. When it cools, it forms new oceanic crust. The old crust is pushed away and new crust takes over.
What is seafloor spreading quizlet?
sea-floor spreading. the process by which molten material adds new oceanic crust to the ocean floor.
What are the steps in the formation of a mid-ocean ridge?
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth's tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
What’s the theory of the seafloor spreading?
Lesson Summary. The theory of seafloor spreading explains that molten material moves in at the boundaries between tectonic plates pushing them apart as new oceanic crust is created. This process is called seafloor spreadingand it occurs at divergent boundaries.
What are the main features of the seafloor?
There are nine main features of the ocean floor which include (1) continental shelf, (2) continental slope, (3) continental rise, (4) abyssal plains, (5) abyssal hill, (6) mid-ocean ridges, (7) seamounts, (8) deep ocean trenches, and (9) volcanic islands.
Which is the correct sequence of oceanic crust from top to bottom?
That extracted magma forms the oceanic crust, whose characteristic rock sequence is, from bottom to top: 1) dark, layered gabbro overlain by massive gabbro (the intrusive equivalent of basalt that comprises solidified magma chambers); 2) sheeted basaltic dikes (the conduits that transported lava from the magma chambers …
What is the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle?
Subduction is the process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle.
What happens during the process of seafloor spreading quizlet?
The process of Seafloor Spreading, squeezes magma up through cracks between the plates and hardens to form a new rock. Then newer eruptions push older rocks away from the ridge. What happens to old oceanic crust as new molten material rises from the mantle.
What process causes subduction and seafloor spreading?
Seafloor spreading and other tectonic activity processes are the result of mantle convection. Mantle convection is the slow churning motion of Earth's mantle.
How and why does seafloor spreading happen?
Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle's convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
What is the importance of seafloor spreading?
Seafloor spreading is the mechanism by which new oceanic lithosphere is created at and moves away from divergent plate boundaries. The seafloor spreading hypothesis led to one of the most important paradigm shifts in the history of the Earth sciences, the plate tectonics scientific revolution.
Where does seafloor spreading happen?
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.
What is happening during 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.
How does the ocean floor form?
As plates converge, one plate may move under the other causing earthquakes, forming volcanoes, or creating deep ocean trenches. Where plates diverge from each other, molten magma flows upward between the plates, forming mid-ocean ridges, underwater volcanoes, hydrothermal vents, and new ocean floor crust.
What do you call the process that forms and moves new oceanic crust?
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.
Which is the process of creating oceanic crust?
Oceanic crust is formed as a result of decompression melting in the mantle at relatively shallow depths below the mid-ocean ridges, as the mantle rises in passive response to plate separation.
Which refer to the process by which the ocean adds new material to the ocean floor?
Sea floor spreading The process that continually adds new material to the ocean floor is – called Sea floor spreading.
What causes seafloor spreading quizlet?
During sea-floor spreading, magma erupts along a mid-ocean ridge to form new oceanic lithosphere. The floor then moves away from the ridge, often toward a trench at the edge of the ocean basin. List the evidence for sea-flooring spreading.
What happens when the sea floor spreads?
At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed. Hydrothermal vents are common at spreading centers. Older rocks will be found farther away from the spreading zone while younger rocks will be found nearer to the spreading zone.
What are the features of seafloor spreading?
Seafloor spreading produces major characteristics of the seafloor – 1) the age of the seafloor is progressively older away from midocean ridges, 2) the elevation of the seafloor is progressively lower away from midocean ridges, 3) the magnetic history of the seafloor bears the striped-pattern of the Earth's magnetic …
What happens when seafloor spreads?
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.
Where do Seafloor spreading occurs?
At mid-ocean ridges, tectonic plates move apart and seafloor spreading occurs. Seafloor spreading is the process by which new oceanic lithosphere forms at mid-ocean ridges. As tectonic plates move away from each other, magma rises from Earth's interior. It then cools and solidifies in the center of the ridge.
What is sea floor spreading theory?
seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them.
What is sea floor spreading simple?
Seafloor Spreading is the usual process at work at divergent plate boundaries, leading to the creation of new ocean floor. As two tectonic plates slowly separate, molten material rises up from within the mantle to fill the opening.
What is seafloor spreading theory?
seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them.
What is the process of ocean formation is called?
Explanation: Ocean-floor spreading happens when volcanic and earthquake activity occurs at the mid-ocean ridges. Lava from rift valley runs through the ridge. The lava will then wells up and hardens, causing the ocean floor to be pushed away from either side of the ridge. The hardened lava forms new ocean floor.
Which of the following is a result of sea floor spreading?
In sea-floor spreading, the sea floor spreads apart along both sides of a mid-ocean ridge as new crust is added. As a result, the ocean floors move like conveyor belts, carrying the continents along with them.