Science PLate Tectonics Flashcards
What is a fact about oceanic crust?
Its is thinner and denser than continental crust.
What is the lithosphere?
Crust and the uppermost part of the mantel. ITs broken up into plate tectonics
What is the asthenosphere?
Convection happens here and this causes plate tectonics to move. The middle part of the mantle. Solid that flows like a liquid.
What is the mesosphere?
Lower solid part of the mantle.
What is the outercore?
The molten layer that surrounds the inner core.
What is the innercore?
It is the deepest layer at the center of the earth that is solid.
What was Wegner’s theory?
Continental drift.
What is continental drift?
Its where continents can drift apart from one another.
What is evidence to support Wegners theory of continental drift?
Glacial features, plant and animal fossils, and rock type
What is the theory of plate tectonics?
ITs the theory of continental drift but modified. Its where the lithosphere is divided into crustal plates that move around the top of the asthenosphere.
What is evidence that supports the theory of plate tectonics?
Sea floor spreading, magnetic, reversals, and locations of volcanoes and earthquakes.
What is Sea floor spreading?
Sea floor spreading is the process by which new ocean crust forms at mid-ocean ridges.
What are mid ocean ridges.
Ocean ridges are underwater mountain chains that form along divergent boundaries. This is where magma rises to the surface and new crust that is formed cools and hardens and eventually gets pushed away as more magma rises.
WHere can you locate older crust?
further away from the mid ocean ridge.
What is Magnetic Reversals?
proof that seafloor spreading occurs. Earth’s north and south magnetic poles change. This happens when the magnetic field changes. As magma rises the minerals orient themselves towards earth’s magnetic north. Same thing when magma cools. So the ocean contains alternating magnetic patterns on either side of the mid-ocean ridge.
