Volcanoes and Layers of the Earth

7th Grade Science

volcano

An opening in the Earth's crust through which molten lava, ash, and gases escape from below the surface. Volcanoes can be classified as active, dormant, or extinct based on their eruption history.

ash

Fine particles of volcanic rock and glass formed during eruptions, often ejected alongside lava and gases.

crater

The bowl-shaped depression at the top of a volcano formed by explosive eruptions or the collapse of the summit.

cone

The conical shape formed by the accumulation of volcanic materials, such as ash and lava, around a vent.

secondary cone

A small volcanic cone that forms on the side of a larger volcano, often as a result of eruptions from fissures or secondary vents.

main vent

volcanic bombs

Large, solid fragments of lava ejected during a volcanic eruption that can solidify before reaching the ground.

lava

Molten rock that erupts from a volcano, leading to the formation of new land and varied volcanic features.

magma

Molten rock located beneath the Earth's surface that can become lava when it erupts from a volcano.

crust

The outermost layer of the Earth, composed of solid rock and soil, supporting life on the planet's surface.

mantle

The thick layer of the Earth located between the crust and the core, consisting of semi-solid rock that flows slowly.

core

The innermost layer of the Earth, comprising a solid inner core and a liquid outer core, primarily made of iron and nickel.

lithosphere

The rigid outer layer of the Earth, combining the crust and the uppermost mantle, that is involved in tectonic activity.

asthenosphere

The semi-fluid layer of the mantle situated beneath the lithosphere, allowing for the movement of tectonic plates.

upper mantle

The layer of the mantle located just below the lithosphere, characterized by solid rock that can flow slowly, contributing to tectonic processes.

lower mantle

The thick, viscous layer of the Earth's mantle located beneath the upper mantle and above the outer core, characterized by high temperatures and pressures.

outer core

The liquid layer of the Earth's core located beneath the mantle and above the inner core, composed mainly of iron and nickel, and responsible for generating the Earth's magnetic field.

inner core

The innermost layer of the Earth's core, composed primarily of solid iron and nickel, and characterized by extremely high temperatures and pressures.