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What is the major evidence that seafloor 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.
What was the evidence of seafloor spreading? The theory of seafloor spreading states that new ocean crust is continually being formed, and that this crust is slowly carried away from its point of origin over a period of time. The study of the repeated reversal of the Earth’s magnetic poles over time has provided convincing evidence of seafloor spreading.
What is the major evidence that seafloor spreading creates new lithosphere? The record of magnetic reversals is carried away from each side of the spreading center of a mid-ocean ridge, showing that the molten rock is creating new lithosphere.
What are three kinds of evidence to show the ocean floor spreading from the ridge? What three types of evidence provided support for the 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.
A polarity reversal means that the magnetic North flips to where we know the South Pole is. This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges. These patterns of stripes provide the history of seafloor spreading.
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. At a spreading center, basaltic magma rises up the fractures and cools on the ocean floor to form new seabed.
How do rocks along the central valley of the mid-ocean ridge provide evidence of sea-floor spreading? They provide evidence of seafloor spreading because the oldest rocks are the farthest away and the newer ones are the closest so they are the new floor pushing away the old rocks.
The correct answer is: Earth’s core contains mostly iron and nickel. Question: Which is evidence that supports the dynamo theory? A. Granite and basalt conduct electricity.
At mid-ocean ridges, tectonic plates move apart and seafloor spreading occurs. It then cools and solidifies in the center of the ridge. The rising magma pushes up between the plates and drives them further apart. As new crust is forming at the spreading center, it pushes the older crust apart.
Which observation about the Mid-Atlantic Ridge region provides the best evidence that the seafloor has been spreading for millions of years? The bedrock of the ridge and nearby seafloor is igneous rock.
New crust can be observed being formed on the sea floor ridges. Matching magnetic lines of reversal along both sides of the ocean ridge also lends support to the theory of sea floor spreading. The subduction zones which form the deep sea trenches also support the theory of sea floor spreading.
Evidence for a fluid outer core includes seismology which shows that seismic shear-waves are not transmitted through the outer core. Because of its high temperature, modeling work has shown that the outer core is a low-viscosity fluid that convects turbulently.
At the dawn of the 21st century, numerical modeling of the Earth’s magnetic field has not been successfully demonstrated. Initial models are focused on field generation by convection in the planet’s fluid outer core.
Magnetic striping is evidence of seafloor spreading.
Which option best explains how volcanoes are formed on Earth? Divergent plates cause mountains to separate, leaving room for magma to enter and erupt. Water just under the crust heats the magma, moves from the mantle to the bottom of the crust, until pressure increases and it erupts.
Mid-Atlantic Ridge. The North American and Eurasian Plates are moving away from each other along the line of the Mid Atlantic Ridge. The Ridge extends into the South Atlantic Ocean between the South American and African Plates.
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart.
seafloor spreading: Supporting Evidence for Seafloor Spreading. 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.
When lava gets erupted at the mid-ocean ridge axis it cools and turns into hard rock. … This creates a symmetrical pattern of magnetic stripes of opposite polarity on either side of mid-ocean ridges. These patterns of stripes provide the history of seafloor spreading.
Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. Fossils tell us when and where plants and animals once existed. Some life “rode” on diverging plates, became isolated, and evolved into new species.
Some of the most convincing evidence for an iron core composition comes from what we know about gravity and energy waves. We know Earth’s size and gravitational pull therefore we can infer Earth’s density.
There are no samples of Earth’s core accessible for direct measurement, as there are for Earth’s mantle. Information about Earth’s core mostly comes from analysis of seismic waves and Earth’s magnetic field. The inner core is believed to be composed of an iron–nickel alloy with some other elements.
No, not all planets have magnetic fields. The four gas giants have extremely strong magnetic fields, Earth has a moderately strong magnetic field, Mercury has an extremely weak field, but Venus and Mars have almost no measurable fields.
Mercury was thought to be cold and dead inside, thus having no magnetic field. However, Mariner measured a weak magnetic field, meaning Mercury must have some internal activity. Probes found that Mars and Venus do not have a significant magnetic field.
Oceanographic exploration in the 1950s led to a much better understanding of the ocean floor. Among the new findings was the discovery of zebra stripe-like magnetic patterns for the rocks of the ocean floor. These patterns were unlike any seen for continental rocks.