Volcano Vocabulary
volcano
a mountain through which molten lava and gases erupt
Ring of Fire
Area around the Pacific Ocean known for frequent earthquakes and volcanoes
eruption
When melted rock, ash, and gases pour out of a volcano when one of earth’s plates in pushed under one another
Magma chamber
The pocket beneath a volcano where magma collects
active volcano
One that is erupting or shows signs that it may erupt in the near future.
dormant volcano
A volcano that has not erupted for a long time, but may erupt again one day.
extinct volcano
One that is unlikely to erupt ever again.
Shield volcano
A wide, gently sloping mountain made of layers of lava and formed by quiet eruptions
Cinder cone volcano
a wide based, steeply sloped volcano that forms from moderately explosive eruptions of pyroclastic material
Composite Volcano/Strato-volcano
Steep, tall peaks, picturesque, composed by pyroclastic flows and lava flows, andesites (Plinian eruption, e.g. Mt St. Halens, Mt. Vesuvieus) occur over subduction zones
explosive eruption
eruption where there are hot debris, ash, and gas shooting into the air
Quiet eruption
occurs when magma flows easily and gently bubbles out, the lava is thin and runny as it oozes out quietly from the vent
lava
magma that reaches Earth’s surface
aa lava
lava that hardens into rough, jagged rocks with a crumbly texture
Pahoehoe
freely flowing lava
archipelago
a group of many islands in a large body of water (Hawaii)
seismograph
an instrument that records vibrations in the ground (used to measure volcanoes and earthquakes)
pyroclastic flow
The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption.
eruption cloud
Cloud of dust, gas and debris caused by volcanic eruption
Mt St. Helens
Erupted on its side in May 1980 and continues to erupt today. Killed 63 people, caused hundreds of millions of dollars in damage, and disrupted people’s lives hundreds of miles from the volcano.
Mt. Rainier
Active, glacier-covered volcano that lies near Seattle
Mt. Hood
Oregon, 11,239 ft., Cascade mountain range
Vesuvius
79 AD, Composite Volcano, Buried town of Pompeii under pyroclastic debris, people were frozen in molds
cindercone
Which type of volcano is relatively small and with steep sides?
fissure
an opening; a groove; a split
crater
a bowl-shaped opening at the top of a volcano
caldera
a large crater caused by the violent explosion of a volcano that collapses into a depression
viscosity
Resistance to flow
What continents are the boundaries for the Ring of Fire?
North America, South America, Asia, and Australia/Oceania
Equator
an imaginary line around the Earth forming the great circle that is equidistant from the north and south poles
Prime Meridian
line of the global grid running from the north pole to the south pole through Greenwich, England; starting point for measuring degrees of east and west longitude