What is seafloor spreading?
Q: What is seafloor spreading?
A: Seafloor spreading is a process that happens at the bottom of an ocean where tectonic plates move apart. As they move, new oceanic crust is created and the continents are carried with it.
Q: What causes seafloor spreading?
A: The motivating force for seafloor spreading ridges is tectonic plate pull rather than magma pressure, although there is typically significant magma activity at spreading ridges. Additionally, convection in the weak upper mantle or asthenosphere also contributes to this phenomenon.
Q: Where does seafloor spreading occur?
A: Seafloor spreading occurs mainly at ridges in the middle of oceans and trenches near continental crusts.
Q: How fast does seafloor spreading take place?
A: The speed of seafloor spreading varies depending on the type of ridge it takes place on; fast ridges have a rate of more than 9 cm/year, intermediate ridges have a rate between 4-9 cm/year, and slow-spreading ridges have a rate less than 4 cm/year.
Q: How does seafloor spreading explain continental drift?
A: Seafloor spreading helps explain continental drift in plate tectonics by showing that as ocean floor moves away from mid-ocean ridge, it carries continents with it as it expands. This modern idea replaced earlier theories (e.g., Alfred Wegener's) which suggested that continents 'plowed' through the ocean instead.
Q: What was Alfred Wegener's theory about continental drift?
A: Alfred Wegener's theory about continental drift was that continents 'plowed' through the ocean instead of being carried by moving ocean floor as modern theories suggest today.
