to move forward or progress.
layers of gases surrounding a planet or other celestial body.
large mass of snow and other material suddenly and quickly tumbling down a mountain.
to change from a liquid to a gaseous state.
impression formed when a liquid substance is poured into a form or mold, and then hardens into that shape.
large settlement with a high population density.
to fall apart completely.
to be made of.
arrangement of the parts of a work or structure in relation to each other and to the whole.
to distort or bend out of shape.
transfer of heat by the movement of the heated parts of a liquid or gas.
type of mineral that is clear and, when viewed under a microscope, has a repeating pattern of atoms and molecules.
remains of something broken or destroyed; waste, or garbage.
having parts or molecules that are packed closely together.
number of things of one kind in a given area.
to come from a specific source or origin.
to ruin or make useless.
having to do with two of something.
release of material from an opening in the Earth's crust.
cylinder-shaped structure of volcanic ash and gas emitted by an explosive volcanic eruption. Also called a volcanic plume.
to grow or get larger.
violent outburst; rejection, usually of gases or fuel
unusual or extraordinary.
area used for agriculture.
side of something.
material that is able to flow and change shape.
ecosystem filled with trees and underbrush.
to make or take shape.
portion or section.
piece or part.
state of matter with no fixed shape that will fill any container uniformly. Gas molecules are in constant, random motion.
person who studies the physical formations of the Earth.
study of the Earth's physical properties and processes.
physical force by which objects attract, or pull toward, each other.
flow of mud and other wet material from a volcano.
body of water surrounded by land.
the geographic features of a region.
the fall of rocks, soil, and other materials from a mountain, hill, or slope.
feature formed as lava hardens over a volcanic vent.
state of matter with no fixed shape and molecules that remain loosely bound with each other.
speed, direction, or velocity at which something moves.
large body of salt water that covers most of the Earth.
small piece of material.
(singular: phenomenon) any observable occurrence or feature.
paste-like material made of crushed stone (usually lime, gypsum, and sand), water, and fiber.
type of igneous rock with many pores.
particles that have been ejected from volcanic vents and have traveled through the atmosphere before falling to earth or into water.
current of volcanic ash, lava, and gas that flows from a volcano.
fluid mass of gas and rock ejected during some explosive volcanic eruptions.
person who lives in a specific place.
material at the bottom of a river.
depression in the earth caused by a river eroding the surrounding soil.
natural substance composed of solid mineral matter.
to destroy by burning.
type of rough, crusty volcanic rock.
to suddenly break into pieces.
precipitation made of ice crystals.
to undergo a sudden, involuntary contraction of a muscle or group of muscles.
body of flowing fluid.
to be unable to breathe.
to keep from falling, sinking, or collecting.
degree of hotness or coldness measured by a thermometer with a numerical scale.
force exerted by a propeller, gas, or other mechanism that propels a vehicle.
crack in the Earth's crust that spews hot gases and mineral-rich water.
up-down direction, or at a right angle to Earth and the horizon.
fragments of lava less than 2 millimeters across.
hard, brittle substance produced by lava cooling very quickly.
an opening in the Earth's crust, through which lava, ash, and gases erupt, and also the cone built by eruptions.
specific danger posed by an active volcano: gas, lahar, landslide, lava flow, pyroclastic flow, or tephra.
scientist who studies volcanoes.
the study of volcanoes. Also called vulcanology.