Chapter 3 Flashcards
Volcano
An opening in Earth’s crust in which molten rock, rock fragments, and hot gases erupt
Lava
Magma that has reached Earth’s surface
Pyroclastic Flow
A dense cloud of super hot gases
What is the difference between lava and magma?
Lava is outside of the volcano, magma is inside
How hot and how fast can pyroclastic flow get?
It can get up to 1500 degrees Fahrenheit and can travel up to 160 km per hour
Where do most volcanoes occur?
Ring of Fire, divergent boundaries, subduction zones, along plate boundaries, around hot spots
What are the three types of volcanoes?
Shield
Cinder Cone
Composite
What are the two volcanoes that can form a caldera?
Shield and composite
What do scientists examine when they monitor volcanoes?
Increase in earthquakes
Changes in tilt of ground
Increased temperatures
Changes in volcanic gas
Descrie magma
Mostly made of silica
High in silica=explosive eruption
Low in silica=less dangerous
Collects in magma chamber
Ash
Tiny rock fragments less than 2 mm in size
Cinders
Contain holes and tunnels left by escaping gases
Block
Large fragments
Main gases in magma
Water vapor and carbon dioxide
Acid rain
Rain that has become more acidic than normal due to pollution
Geyser
Hot spring that shoots out water
Name two materials that erupt from volcanoes
Rock fragments and gases
Lava flows
Flow of molten rock at Earth’s surface
Can knock down and burn things
Volcanic ash
Tiny pieces of rock
Can suffocate plants, animals, and people
Landslides
A rapid downhill movement of rock and soil
Can cover objects and cause tsunamis
Mudflows
Landslides that occur when loose rocks and soil are mixed with water
Can bury towns
Steam explosions
Occur when magma comes near water
Can cause huge explosions, some capable of destroying whole islands
Immediate Effects on land(negative)
Lava flows Volcanic ash Mudflows Pyroclastic flow Landslides Steam explosions
Long term effects on land(negative)
Mudflows continue for years
Water filling up craters
Long term effects on land(positive)
Form rich soil for farming
Creates beautiful land for tourism
Effects in air(negative)
Gases cause breathing problems/death
Acid rain
Change weather
Ash travels far and can stay there for years
Effects in water
Tsunami Geysers Hot springs Fumaroles Deep sea vents
Magma chamber
Where magma collects when it stops rising underground
Fumarole
A hot spring that releases steam and other gases
How does the amount of silica and viscosity affect the type of explosion?
High in silica resists flowing
Low in silica pours easily
Viscosity is how easily it flows
Why do scientists monitor volcanoes?
For signs of eruptions
Describe a shield volcano
Built of layers of lava
Broad, flat dome
Shield shaped
Low in silica
Describe a cinder cone volcano
Steep, cone shaped hill
Formed by eruptions of cinders and rock fragments
Describe a composite volcano
Cone shaped
Built of layers of lava and layers of rock fragments
High in silica
What is the difference between a geyser and a fumarole?
A geyser shoots water, a fumarole releases steam and gases
Deep Sea Vent
Hot springs that form at spreading centers in the ocean
Lahar
Mudflow that is very dangerous because it acts like cement
Pumice
Volcanic rock that resembles a sponge
