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Worn by wind
Strong winds can
lift sand off the
ground and blast it
hard against rocks.
The rock is worn
into strange shapes.
Hills of sand
In deserts, winds blow sand
into hills called dunes. In
some deserts the dunes
stretch for hundreds
of miles, forming a
“sand sea”.Floods
Heavy rain makes
rivers overflow,
causing floods.
Floods have
enormous power
and can wreck
buildings and
re-shape the land.New islands
Some volcanoes
are hidden under
the sea. When they
erupt, they can give
birth to whole new
islands, like Surtsey
in Iceland (left).
Surtsey burst out
of the sea in 1963.Shaping the land
Before flood After floodMount Kilauea in Hawaii.