Here's a breakdown:
* Seafloor Spreading: Hess proposed that new oceanic crust is continuously being generated at mid-ocean ridges, where magma rises from the mantle and solidifies. This new crust then moves away from the ridge in opposite directions, carrying the continents along with it.
* Mid-Ocean Ridges: These are underwater mountain ranges where new oceanic crust is formed. The process of magma rising, cooling, and solidifying creates the new crust.
* Evidence Supporting Seafloor Spreading:
* Magnetic Stripes: Symmetrical patterns of magnetic anomalies on either side of the mid-ocean ridges, reflecting reversals in Earth's magnetic field.
* Age of Ocean Floor: Oceanic crust gets older further away from the mid-ocean ridges, suggesting the spreading process.
* Sediment Thickness: Thinner sediment layers closer to the ridge, thickening further away, due to a younger ocean floor.
Hess's theory of seafloor spreading was a revolutionary concept that revolutionized our understanding of plate tectonics and how the Earth's surface has evolved over time.
