Volcanoes: Glossary

A

Algae

an aquatic plant

Ancient

a time in history that no longer exists

a'a

lava with a rough surface

B

Bulbous

a swollen bubble - puffed out

Bulging

to protrude as in a bump

beneficial

good

boundaries

the edges of the plates where they come together

C

Cinder

material blown out of the volcano that has cools before it falls

Conic

cone shaped

Crater

a cup shaped depression or opening in a volcano

Crust

outer layer of the earth's surface

Crystals

a clear mineral formation made of flat sides

central vent

the main opening of a volcano

cinder volcano

volcano made largely from cinders

composite volcano

volcano made of layers of cooled lava flows

continents

one of seven main land masses on the earth

convection

the transfer of heat by movement

D

Dormant

no longer active

E

Erosion

process that wears away the earth's surface

Erupt

the movement of material from inside a volcano to the outside

Expand

to make larger

Extinct

no longer living

earthquakes

vibrations of the earth's surface

F

Frothy

foamy or full of air

G

Geologic

related to the earth and its construction

Geysers

steam and hot water that spews from the earth

Gravity

the natural law that causes objects to be attracted to each other

gas bubbles

bubbles formed when gasses get trapped

H

heat resistant

protects against heat

hot spots

areas in the mantle where rocks melt

hydrothermal

related to hot water

I

Inactive

not active

inhabited

where people live

inner core

solid layer of the earth made of iron

intolerable

living things cannot survive under this condition

J

jet stream

a wind on the earth that moves west to east and is the major source of weather movement

L

Lava

melted rock that has escaped onto the outside of the crust

laboratories

a place where scientific studies or experiments take place

lava dome

a bulge of lava that never flows

M

Magma

melted rock that is inside of the earth

Mantle

layer of the earth between the crust and the outer core where magma moves from heat

magma chamber

location where the magma sits before it erupts - also known as magma reservoir

magma reservoir

location where the magma sits before it erupts - also known as magma chamber

magnetic field

region of space around the earth affected by the magnetic force within the earth

O

observatory

a place where scientists study volcanoes

outer core

area inside the earth between the inner core and the mantle

P

Pangaea

original continent in earth's history

Predict

tell in advance

pahoehoe

smooth lava with wrinkle and twists

pillow lava

lava that erupts under water and cools quickly

poisonous chemical

gases that are dangerous to life

prehistoric

before humans were around to record the event

pressure

a pushing force

pyroclastic flow

a cloud of ash, dust and other debris along with gas erupting from a volcano

R

Ring of Fire

boundary of tectonic plates along the Pacific Ocean - majority of earthquakes and volcanoes take place here

Rotates

turns

Rupture

a broken place

S

secondary vent

a vent which branches off the central vent of a volcano

shield volcano

a large volcano spread out over the ground - fairly flat rather than mountain-like

solar system

the sun, planets and other space bodies nearby

T

tectonic plates

plates that make up the earth's crust

V

Vent

an opening in the earth's surface

viscosity

the property that causes a liquid to flow

volcanologist

scientist who studies volcanoes

W

weathering

the process that breaks down rocks