Seafloor Spreading Concepts

Questions and Answers

What is the crust?

The thin, solid, outermost layer of Earth; is either continental (landmasses) or oceanic (ocean floors).

What is a divergent boundary?

The boundary between two tectonic plates moving away from each other; if on land, it creates rift valleys; if on the sea floor, it creates new ocean crust and mountainous ridges.

What is magma?

Melted or molten rock material beneath Earth's surface; cools slowly to form rocks with larger crystals.

What is a mid-ocean ridge?

An underwater mountain system formed by plate tectonics; the largest single volcanic feature on Earth. Signup and view all the answers

What is seafloor spreading?

The formation of new areas of oceanic crust, which occurs through the upwelling of magma at mid-ocean ridges. Signup and view all the answers

What is subduction?

The process in which a denser plate is pushed downward beneath a less dense plate when plates converge. Signup and view all the answers

What are tectonic plates?

Huge pieces of crust that slowly move on the upper part of the mantle by convection. Signup and view all the answers

What are trenches?

Deep and narrow depressions in the seafloor; form where the subducted plate moves into the mantle. Signup and view all the answers

What is a convergent boundary?

Occurs when two tectonic plates move toward each other and collide. Signup and view all the answers

What is an ocean basin?

A depression of Earth's surface in which an ocean lies. Signup and view all the answers

What is a divergent (spreading) boundary?

Where new seafloor is made and a plate 'grows'. Signup and view all the answers

What is a convergent (come together) boundary?

Where plates collide. Signup and view all the answers

What is oceanic crust?

Earth's crust below the seafloor. Signup and view all the answers

What is continental crust?

Crust below the continents. Signup and view all the answers

Study Notes

Crust

Outermost layer of Earth; can be continental (landmasses) or oceanic (ocean floors).

Divergent Boundary

Boundary where tectonic plates move apart; results in rift valleys on land and new ocean crust at mid-ocean ridges.

Magma

Molten rock material beneath Earth's surface; cools to form rocks with larger crystals.

Mid-Ocean Ridge

Largest underwater mountain range formed by plate tectonics; significant volcanic activity occurs here.

Seafloor Spreading

Process of new oceanic crust formation through magma upwelling at mid-ocean ridges.

Subduction

Occurs when a denser tectonic plate is forced below a less dense plate during plate convergence.

Tectonic Plates

Massive crustal segments that shift on the upper mantle due to convection currents.

Trenches

Formations in the seafloor where subducted plates descend into the mantle, creating deep depressions.

Convergent Boundary

Interaction zone where two tectonic plates collide, often resulting in geological activity such as earthquakes.

Ocean Basin

Depressed areas of Earth's surface that host oceans.

Divergent (Spreading) Boundary

Specific zone where new seafloor is generated, contributing to the growth of tectonic plates.

Convergent (Come Together) Boundary

Defined area where tectonic plates clash, leading to geological formations such as mountains.

Oceanic Crust

The portion of Earth's crust located beneath the ocean surface.

Continental Crust

Earth’s crust layer that forms the continents, generally thicker and less dense than oceanic crust.

Description

Test your knowledge on the fundamental concepts of seafloor spreading, including key terms such as crust, divergent boundaries, and magma. This quiz will help you understand the processes that shape our planet's ocean floors.