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Mudslides and landslides Rockslide
Landslides
Landslides occur when masses of earth or rock move down
a slope. When combined with water and debris, a faster
moving mudslide is formed. Areas where wildfires or human
activities have destroyed vegetation on slopes are more
vulnerable to landslides.
Vargas mudslide, Venezuela, 1999
In December 1999, deadly landslides occurred in
the Vargas state of Venezuela. This coastal area is
located at the base of steep mountains rising up
to two thousand metres. Heavy rainstorms during
14–16 December led to 911 millimetres of rainfall.
This caused landslides, massive flash floods, and
debris flows in the coastal mountains. The rapidly
moving flows carried with them water, mud, and
whatever came their way—cars, small houses, and
uprooted trees. Massive boulders, as large as ten
metres in diameter, were deposited in layers up to
several metres thick.
Impact …
The tragic event changed the geography of
Vargas! Streams and rivers changed channels,
and hill slopes had new shapes. Between
10,000 to 30,000 people were killed. People
did not get enough warning and were either
trapped in their houses or swept away to
sea with the flows. Hundreds of houses,
bridges, and other structures were damaged
or destroyed. The total damage in Vargas was
worth nearly two billion dollars.
Landslides are
dangerous phenomena in
mountainous regions.
TICKER An earthquake in Lituya Bay, Alaska, in 1958 triggered a landslide, which caused dirt and glacier
Landslides
Landslides occur when masses of earth or rock move down
a slope. When combined with water and debris, a faster
moving mudslide is formed. Areas where wildfires or human
activities have destroyed vegetation on slopes are more
vulnerable to landslides.
Vargas mudslide, Venezuela, 1999
In December 1999, deadly landslides occurred in
the Vargas state of Venezuela. This coastal area is
located at the base of steep mountains rising up
to two thousand metres. Heavy rainstorms during
14–16 December led to 911 millimetres of rainfall.
This caused landslides, massive flash floods, and
debris flows in the coastal mountains. The rapidly
moving flows carried with them water, mud, and
whatever came their way—cars, small houses, and
uprooted trees. Massive boulders, as large as ten
metres in diameter, were deposited in layers up to
several metres thick.
Impact …
The tragic event changed the geography of
Vargas! Streams and rivers changed channels,
and hill slopes had new shapes. Between
10,000 to 30,000 people were killed. People
did not get enough warning and were either
trapped in their houses or swept away to
sea with the flows. Hundreds of houses,
bridges, and other structures were damaged
or destroyed. The total damage in Vargas was
worth nearly two billion dollars.
Landslides are
dangerous phenomena in
mountainous regions.
TICKER An earthquake in Lituya Bay, Alaska, in 1958 triggered a landslide, which caused dirt and glacier
