randomness, magnitude, frequency, regularity of volcanic hazards

Question 1

what is the volcano explosivity index (vei)?

Answer 1

the volume of products (ash, lava etc), eruption height and qualitative observations are used to determine explosivity value

• open ended scale but largest volcanoes in history given an 8
• value of 0 given for non explosive
• scale is logarithmic, each interval represents a 10 fold increase in ejected material