Formation
10% if volcanoes form over these.
Hot spots
Lava's main ingredients are _________ and __________.
Silicate and gas
Lava is worn away by _________ and ____________
wind and weathering
Are the most powerful eruptions
Plinian eruption
Is an instrument that uses water to register changes in the Earth.
Tiltmeter
60% of volcanoes form along what plate (name)?
Pacific Plate
Pahoehoe has two forms, name them.
Puffy pillows - black clouds
Ropy-textured
Does magma change rock all the way around or just underneath it
All the way around
They eject pasty lava named after the island Vulcano.
Vulcanian eruptions
Sometimes magma heats underground water system and the pressure is released in the form of hot steam. This is known as a __________.
Geyser
Volcanoes grow larger in two ways. Name them.
Inside - magma remains in cone
Outside - lava piles up
What type of lava can shred the soles of your shoes.
Aa
Pyroclastic means:
Fire rock
Consist almost entirely of loose, grainy cinders with almost no lava.
Cinder cones
Name 2 things volcanoes and their ash can do.
Block out the sun for days
smother crops and clog rivers
can even change the climate
What is the name of the rim in the Pacific called?
Ring of Fire
This can be ground into powder and used in toothpaste
Pumice
Volcanic bombs have a distinct shape, what is this shape?
Tear-shaped
Also known as stratovolcanoes.
Composite volcanoes
A large circular depression can form at the top of volcano known as a ___________.
caldera
At plate boundaries when one plate is forced under another.
Winds can carry these hundreds or thousands of miles.
Ash clouds
These are made of finely broken rock fragments and gas
ash clouds
What does VEI stand for?
Volcanic Explosivity Index
Name all the types of eruptions - there are 6.
Icelandic, Hawaiian, Strombolian, Vulcanian, Pelean, Plinian