Factors such as: Types of Volcanic material ejected, The types of eruptions, and geographical location of a place are some of the factors that affect the impact of volcanoes

1. • Type of Volcanic Eruptions
• Type of Volcanic Materials Ejected
• Geographical Location of a Place

2. EFFUSIVE ERUPTION EXPLOSIVE ERUPTION
 Eruptions are quiet
 Non-explosive
 Spew basic lava that
spreads out over large
areas
 Less dangerous as
people rarely get killed
 E.g.: The Kilauea
volcano in Hawaii.
 Eruptions are loud &
Violent
 Explosive because of
pressure building up in
the magma
 Eject acid lava, ash,
gases & rock fragments
 Dangerous as the
materials can rain down
on settlement
 E.g. The Krakatau in
Indonesia

3.  LAVA FLOWS
◦ Less dangerous to
humans
◦ Travel slowly &
people are able to
avoid them
◦ However, death may
occur if the lava
flows block people’s
escape routes.
 ASH –(smallest &
finest fragments of
lava or rock)
◦ Ash in the air can
block sunlight &
reduce visibility.
◦ Disrupt people’s
activities.
◦ Cause asthma &
coughs

4.  VOLCANIC BOMBS
◦ Large fragments of
volcanic rock. Semi-
solid or partially
molten
◦ Cause severe
injuries & death to
humans.
 POISONOUS GASES
◦ Trapped in magma are
released into the
atmosphere when
volcanoes erupt
explosively
◦ Carbon Dioxide: can
harm vegetation & air
that has more CO2 can
cause death in people &
animals
◦ Sulphur Dioxide:
contribute to the
formation of acid rain.
Causes skin, eye, nose &
throat irritations.

5.  PYROCLASTIC FLOWS
◦ Gases mix with
volcanic materials
◦ Fall down very quickly
down the slopes (up to
100km/h)
◦ Temp: 200 °C–700 °C
◦ They will burn, knock
over or bury anything
in their path
 LAHAR (mudslide)
◦ Occurs when water
mixes with ash &
rock fragments.
◦ Flow very fast
◦ Very destructive and
can bury anything in
their path.

6.  Volcanoes mostly located at plate boundaries
◦ Countries that are in close proximity such as
Indonesia & Philippines will experience more
impacts compare to Brunei.
 The impact is greater if the volcanoes are
located in close proximity to settlements.
◦ Densely populated settlements will be at risk.