Seafloor Spreading and Magnetic Evidence

The video explores seafloor spreading, a key concept in plate tectonics, starting with Alfred Wegener's theory of continental drift. It discusses the development of ocean floor mapping using sonar by scientists like Marie Tharp and Bruce Heezen, revealing the jagged and active nature of the seafloor. The video presents four key pieces of evidence for seafloor spreading: the geological features of the ocean floor, the age of seafloor rocks, sediment thickness, and magnetic patterns. These evidences collectively support the theory of plate tectonics, explaining the movement of Earth's plates.

Who proposed the theory of continental drift?

• Marie Tharp

• Bruce Heezen

• Alfred Wegener

• Harry Hess

What technology did Marie Tharp and Bruce Heezen use to map the ocean floor?

• Sonar

• GPS

• Satellite Imaging

• Radar

What geological feature runs down the center of the Atlantic Ocean basin?

• A deep trench

• A massive scar

• A vast expanse of flat desert

• A large plateau

What is the first piece of evidence supporting seafloor spreading?

• Patterns of seafloor magnetism

• Active fractures in the lithosphere

• Thickness of sediment layers

• Age of seafloor rocks

How does the age of seafloor rocks change as you move away from the mid-ocean ridge?

• It decreases

• It fluctuates randomly

• It remains the same

• It increases

What happens to the thickness of sediment layers as you move away from the mid-ocean ridge?

• It decreases

• It remains the same

• It increases

• It fluctuates randomly

What phenomenon involves the switching of Earth's magnetic north and south poles?

• Magnetic reversal

• Magnetic inclination

• Magnetic alignment

• Magnetic declination

What records the Earth's magnetic field in solidified rock at mid-ocean ridges?

• Sediment layers

• Tectonic plates

• Minerals within the magma

• Ocean currents

What is the fourth piece of evidence supporting seafloor spreading?

• Age of seafloor rocks

• Thickness of sediment layers

• Patterns of seafloor magnetism

• Active fractures in the lithosphere

Which concept is proven by the four key pieces of evidence discussed in the video?

• Earthquake prediction

• Continental drift

• Seafloor spreading

• Volcanic activity