The video discusses Alfred Wegener's theory of continental drift, initially rejected due to lack of explanation for the movement of continents. Advances in technology in the mid-20th century allowed scientists to explore the ocean floor, leading to the discovery of mid-ocean ridges and volcanic activity. The theory of seafloor spreading emerged, suggesting that continents ride on moving oceanic plates. Evidence supporting this theory includes young ocean floor rocks, magnetic orientation of basaltic rocks, and parallel magnetic stripes on either side of mid-ocean ridges.

Why was Alfred Wegener's theory of continental drift initially not accepted?

• He proposed the theory too late.

• He lacked support from other scientists.

• He had no evidence of ocean ridges.

• He could not explain the mechanism of drift.

What discovery in the mid-20th century helped scientists understand the ocean floor better?

• Deep-sea trenches

• Underwater volcanoes

• Mid-ocean ridges

• Coral reefs

According to the theory of seafloor spreading, what happens at mid-ocean ridges?

• Tectonic plates merge

• Ocean currents change

• Seafloor separates

• Continents collide

How did the theory of seafloor spreading explain the movement of continents?

• Continents ride on ocean floor segments

• Continents are pushed by ocean currents

• Continents drift independently

• Continents are stationary

What evidence supports the theory of seafloor spreading?

• Uniform age of ocean rocks

• Lack of volcanic activity

• Magnetic stripes on ocean floor

• Older rocks near mid-ocean ridges