Seafloor Spreading

How does seafloor spreading affect oceanic and continental crust?

• Seafloor spreading creates new oceanic crust while pushing older crust away, which can lead to the formation of continental crust over time.

• Seafloor spreading causes the oceanic crust to sink into the mantle, leading to the destruction of continental crust.

• Seafloor spreading has no effect on the formation of continental crust, as it only affects oceanic crust.

• Seafloor spreading results in the thickening of oceanic crust without impacting continental crust.

What is the relationship between mid-ocean ridges and earthquakes?

• Mid-ocean ridges are often sites of earthquakes due to the movement of tectonic plates.

• Mid-ocean ridges are completely stable and do not experience earthquakes.

• Mid-ocean ridges are formed by volcanic activity and are not related to earthquakes.

• Mid-ocean ridges are areas where earthquakes are rare and insignificant.

What role do volcanic islands play in seafloor spreading?

• They are formed by tectonic plate collisions.

• They indicate areas of seafloor spreading due to magma rising from the mantle.

• They prevent seafloor spreading by blocking magma flow.

• They are remnants of ancient landmasses that have eroded away.

Where are the oldest rocks found in relation to mid-ocean ridges?

• The oldest rocks are found near the mid-ocean ridges.

• The oldest rocks are found at the mid-ocean ridges.

• The oldest rocks are found far from the mid-ocean ridges.

• The oldest rocks are found directly above the mid-ocean ridges.

What is a tectonic plate?

• A large slab of solid rock that makes up the Earth's lithosphere and moves over the asthenosphere.

• A type of cloud formation in the atmosphere.

• A layer of liquid rock beneath the Earth's surface.

• A geological feature that only exists on Mars.

What is the significance of the age of seafloor rocks?

• It helps scientists understand the history of Earth's geological activity and the rate of seafloor spreading.

• It determines the temperature of ocean water.

• It indicates the presence of marine life in the area.

• It reveals the chemical composition of seawater.

What is a mid-ocean ridge?

• A type of underwater volcano that erupts lava

• An underwater mountain range formed by plate tectonics, where new oceanic crust is created.

• A deep-sea trench where oceanic plates converge

• A large body of saltwater that separates continents

Where is new crust always formed?

• At the mid-ocean ridge.

• At continental plate boundaries.

• In volcanic hotspots.

• At the ocean floor trenches.

True or False: Seafloor spreading adds new material to the ocean floor?

• True

• False

• Sometimes

• Rarely

What happens at a deep-ocean trench?

• One tectonic plate is being subducted under another, leading to the recycling of oceanic crust.

• Oceanic crust is formed as magma rises to the surface.

• Deep-ocean trenches are areas where marine life thrives due to abundant sunlight.

• Tectonic plates are moving apart, creating new oceanic crust.