Ash Falling
Although lava flows can destroy buildings, they
rarely result in a direct loss of life – they travel
slowly enough for you to walk away!
Pyroclastic flow
These form when ash mixes with water and travels
down river valleys. Because mud is much denser
than water, mudflows are very destructive –
washing away buildings, roads, bridges, and people.
Lateral blasts
Because of the sulfur dioxide and hydrogen sulfide
released, very large eruptions cause acid rainfall.
This can damage buildings, and may have had very
serious effects on plant and animal species in the
past.
Mudflow/lahars
Fine ash is blasted into the atmosphere, where it
can stay in suspension for many months – affecting
areas far away from the volcano. It mostly damages
property by burying buildings; people are not
usually harmed directly. Ash can also be a hazard to
aircraft and lead to the cancellation of flights.
Sometimes ash clouds can block the sun, causing
the weather to be cooler and affecting crops
Volcanic gases
Sometimes a volcano can explode sideways, which
can be very destructive for areas within 40 km of
the volcano. It can destroy houses and property.
Acid Rain
The disruption to homes, roads and services caused
by the effects described above can result in famine
and disease, especially in LEDCs
Post-eruption famine
and disease
The collapse of volcanoes into the sea can result in a
tsunami
Tsunamis
Very hot solid material can travel rapidly down
valleys and slopes. It is impossible for people to
escape, so pyroclastic flows can be responsible for
many deaths. A famous example was the eruption
of Mt Pelée in Martinique in the West Indies in
1902, when a white-hot glowing ash cloud killed 40
000 people.
Lava Flows
Carbon dioxide is a dense, non-toxic gas that can
flow downhill, causing suffocation. Other gases that
are poisonous can burn or cause lung diseases.