geological basics and facts on volcanoes Flashcards
1
Q
630,000 years ago how many km3 of rock were expelled by yellowstone?
A
1000
2
Q
what is a shield volcano?
A
a lava cone built up by successive flows of lava from a central vent
3
Q
what is a volcanic dome?
A
a bulbous, steep sided mass rock
*produced by andesitic and rhyolitic lavas
4
Q
what are stratovolcanoes?
A
a concave composite volcano built up by many layers of hardened lava and volcanic ash
5
Q
what percentage of the world’s active volcanoes are on subduction boundaries?
A
80%
6
Q
how many people live close enough to active volcanoes to be directly affected by them?
A
> 600 million people
7
Q
how many high risk volcanoes are in the world today?
A
100
