Volcanic Hazards and Why people live near them Flashcards
What are the primary effects of a volcano?
They are caused instantly by the eruption. These are directly linked to the volcano e.g. lava, acid, rain, gases and earthquakes.
What are the secondary effects of a volcano?
In the hours, days, weeks after the eruption. These are often caused by the volcano e.g. disease, food and water shortages.
Why do people live near volcanoes?
Volcanic rock and ash provide fertile land which results in a higher crop yield for farmers.
What is pyroclastic flow?
It is hot ash debris which destroys everything in it’s path which moves very fast at 1000 degrees Celsius.
How are tsunamis caused?
Occasionally an earthquake caused by a volcanic eruption can set off a tsunami.
Why is ash dangerous?
Large amounts of ash fall can lead to roof collapse as well as burying crops, making roads impassable and making it hard to breathe.
What are Lahars?
These can be extremely powerful.
Flood water mixed with ash creates mudflow that can wash away whole settlements.
What are Lava Bombs?
Large rocks and even boulders can get thrown from the volcano quite some distance.
What gases are released into the atmosphere from the ground below?
Sulphur dioxide Hydrogen sulphide carbon dioxide carbon monoxide which can kill lol
There can be _____ of _____ earthquakes ___ and ____ an eruption.
hundreds
small
before
after
Why are earthquakes caused?
Caused by the upwelling of magma from the lower chamber up the main vent and the volcano bulging in size.
