Volcanos Flashcards
What is a volcano
A volcano is a mountain formed the eruption of magma on the earths surface through a hole or a vent
Give an example of a volcano
Mount Fuji, japan
Mt. St Helens
Yellowstone
Mt. Etna
Eyjafjallajökull
What is magma called once it reaches the surface and what happens when it cools
It is called lava and it soon turns into basalt rock once it cools down
What is a fissure
A fissure is a crack in the earths crust
What is a plateau
An area of fairly levelled high ground
What determines the strength of a volcanic blast
The amount of silica there is in the magma determines the strength of the blast
What does silica do to explosions
Magma with lots of sillica in it traps lots of gas, making it sticky and thick, which usually causes a big explosive eruption. This usually makes a cone shaped volcano (E.g Mount St Helens)
Magma with less silica traps less gas in it, casing it to be more runny, like water so it is less eruptive when it exploded. This usually makes more wider shield-shapes cone volcano (e.g Hawaiian islands)
What is the name of a super heated mix of dust, gas and rocks, and how fast can it travel
Pyroclasts is the name for it, and it can travel from 100km/h to 800km/hr. This is called Pyroclastic flow
Draw a diagram of a volcano (+labels)
Draw 3-4 times
Labels: magma chamber, layers of ash and lava, ash cloud, crater, lava & vent
Where do volcanos form
Hot spots
Where plates collide
Where plates separate
How are volcanos caused in the Pacific Ring Of Fire
They are formed by the pacific plate colliding with the surrounding plates; Eurasia, North America and Australia.
How much of volcano eruptions happen in the pacific ring of fire
Over 90% of eruptions happen In the pacific ring of fire (e.g Mount Fuji, japan & Krakatoa, Indonesia)
What is the name for a chain of underwater volcanos
A ridge (e.g the mid-Atlantic ridge)
Life cycle of a volcano
Active: the volcano is still continuously erupting
Dormant: the volcano is sleeping, it has not erupted in a long time but could erupt anytime
Extinct: the volcano has not erupted for at east 10,000 years and is not expected to erupt ever again
Name 4 environmental impacts of a volcano
- Ash and dust pollute atmosphere
- Ash makes soil fertile
- New land made
- Pyroclastic flow destroys town/village & farmlands
- Tsunamis & lahars (a hot or cold mix of rock bits or water that flow down volcano side, ending in rivers)
Name 4 social impacts of a volcanic eruption.
- Loss for life
- Injured people living in fear
- Forced migration
- Aircraft flights disrupted
- Lack of clean water; disease spreads quickly
What is someone who monitors volcanos called?
A volcanologist
Name 3 warning signs of a volcanic eruption.
- Small earthquakes
- Increase of gas emissions
- Eruptions of steam or rock
What do volcanologists monitor
- Unusual gas emissions
- Water level in wells
- Changes in the shape of a volcanic cone (using GPS tracking)
What is the VEI scale and what does it stand for
the VEI scale is the scale that measures the force of eruptions. It stands for Volcanic Eruption Index
what is the scale range for a VEI scale
0 - 8
name any three active volcanos
Mt. St Helens
Yellowstone caldera
Mount Etna
Mount Vesuvius
