Two type of volcano
Shield and strato
what are properties of high silica magma
very viscous, causes explosive eruption due to dissolved gases that cannot escape easily, stratovolcano
What are properties of low silica magma
Less viscous, erupt effusive, found on n shield volcano
What are stratovolcanoes?
steep sloped volcano that erupts explosively, e.g. Mount Mayon and Metapi Indonesia
What are shield volcanoes
Gentle slopes volcano that erupts effusively, e.g. Mauna Loa and Kilauea
How to measure volcanic eruptions
VEI- volcanic explosivity index
Based on volume of ejected material, height of eruption cloud and length of eruption(higher values, higher VEI). Scale of 0-8 (log scale)
How are volcanoes formed?
DIVERGENT: plates move apart, mantle melt, magma rise, become lava solidify form volcano
CONVERGENT: subduction, subducted plate melt, magma rise, become lava solidify form volcano
Distribution of volcano?
Mostly found at convergent plate, few at divergent, none at transform
Type of volcanic hazard?(6)
Tephra(rocks fall from sky), volcanic gases, lava flows, pyroclastic flow, lahar, volcanic land slides
Impacts?
social: people die/injure
Economic: rebuild houses/roads/railways
Environmental: affects habitats, river pollution cause death of wildlife