Seafloor Spreading & Subduction Concepts

Questions and Answers

What is the crust?

Layer composed of liquid metals

The molten rock beneath the surface

Thin, solid, outermost layer of Earth (correct)

A type of tectonic plate

What is magma?

Melted or molten rock material beneath Earth's surface

What is a mid-ocean ridge?

An underwater mountain system formed by plate tectonics

What does seafloor spreading refer to?

The formation of new areas of oceanic crust Signup and view all the answers

What is subduction?

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

What are tectonic plates?

Huge pieces of crust that move on the upper part of the mantle 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

What is Pangaea?

Name of the supercontinent where all of Earth's continents were once joined Signup and view all the answers

Who is Harry Hess?

He proposed the theory of sea-floor spreading Signup and view all the answers

Who is Alfred Wegener?

He proposed the theory of continental drift Signup and view all the answers

What is a trench?

Extremely deep areas in the ocean created by a subducting plate Signup and view all the answers

The oceanic plate subducts when the oceanic and continental lithospheres collide.

True Signup and view all the answers

Study Notes

Key Concepts in Plate Tectonics

Crust: Earth's outermost layer, comprising continental (landmasses) and oceanic (ocean floors) varieties.
Magma: Molten rock beneath the Earth's surface that cools to form rocks with larger crystals.
Mid-Ocean Ridge: An underwater mountain range created by the movement of tectonic plates.
Seafloor Spreading: The process that generates new oceanic crust through magma upwelling at mid-ocean ridges.
Subduction: The mechanism where a denser tectonic plate sinks beneath a less dense plate during convergence.
Tectonic Plates: Massive sections of Earth's crust that shift on the mantle's upper layer due to convection currents.
Oceanic Crust: The section of crust that lies beneath the ocean, denser than continental crust.
Continental Crust: The part of Earth's crust that forms the continents.
Pangaea: The historical supercontinent where all current continents were once interconnected.

Notable Figures

Harry Hess: Geologist who introduced the theory of seafloor spreading, enhancing the understanding of ocean floor formation.
Alfred Wegener: Scientist who formulated the continental drift theory, proposing continents once formed a single landmass.

Geological Features

Trench: Deep ocean regions created by the subducting plates, marking significant geological activity.
Oceanic Plate Subduction: Occurs when oceanic and continental lithospheres collide; the oceanic plate is denser, causing it to dive beneath the continental crust.

Description

This quiz covers essential terminology related to seafloor spreading and subduction, including definitions of crust, magma, and mid-ocean ridges. Enhance your understanding of Earth's geological processes by testing your knowledge with these key concepts.