About 10 percent
of the world’s
population (~360
million people)
live on or near
potentially
dangerous
volcanoes. Many
of the processes
that take place
on active
volcanoes are
potentially
hazardous to
local
populations.
Emergence of
volcanology as a
modern
multidisciplinary
science was
largely a result
of volcanic
catastrophes
that occurred at
Krakatau Volcano
in Indonesia in
1883 and at
three localities
in the Carribean-Central
American region
in 1902
including Mont
Pelee on
Martinique,
Soufriere on St.
Vincent, and
Santa Maria in
Guatemala. A
total of 72,980
fatalities
resulted from
these four
eruptive events
that occurred
over a nineteen
year period.
Potentially
hazardous
geologic
processes
include eruption
of lava flows
and domes,
pyroclastic
density currents
(including
high-temperature
pyroclastic
flows and
surges), cool
base surges and
directed
blasts.
Other
hazards include
lahars and
floods,
structural
collapse, tephra
falls and
ballistic
projectiles,
volcanic gases,
volcanic
earthquakes,
atmospheric
shock waves and
tsunamis. In
some cases,
remobilization
of tephra long
after eruption
can also give
rise to
significant
volcanic
hazards. In
addition,
explosive
volcanism can
pose significant
hazards to
commercial air
traffic over
many regions and
particularly
along
circum-Pacific
routes.