Shake, Rattle and Liquefy
Modified from a classroom lesson
prepared by Wendy Gerstel,
Washington Division of Geology and Earth
California, the effects of an earthquake
commonly are amplified in areas
underlain by sandy unconsolidated
sediments in. Common geologic settings
for liquefaction include unlithified
sediments in coastal regions, bays,
estuaries, river floodplains and basins,
areas surrounding lakes and reservoirs,
wind-deposited dunes and loess. When
such sediments liquefy, they lose their
structure and strength. During
earthquake shaking, the individual
grains of sand within a deposit collapse
on each other. Any structure built on
sandy sediments can sink or collapse.
Picture a container of balls of
different sizes: baseballs, golf balls,
marbles. If they were transported by
water into the container and then
deposited, they would settle with spaces
between them. Some of the spaces would
be filled with water, some with air.
When you shake the container, the balls
settle against each other, and the water
and air are forced to the surface. That
is exactly what happens in a
sediment-filled valley. The valley is a
large "container" holding gazillions of
"balls" or grains of sand. Shaking the
container simulates an earthquake.
This experiment demonstrates what
happens to sandy soils when they
liquefy. You will create a model river
valley, then watch how and why houses
get damaged or collapse during an
earthquake in a seemingly stable
glass baking pan or plastic bin (so
contents of pan can be observed)
enough dry sand to fill pan 1-2 inches
a few toy houses or blocks
Evenly pour the dry sand into the pan.
Mark the level of the sand on the side
of the pan or bin (use a washable marker).
Place houses or blocks gently on the
Slowly add water until about
two-thirds of the thickness of the
sand is saturated.
Gently shake the table on which you
have placed your pan (or gently shake
the pan itself). If using a plastic
bin, you can use a rubber mallet to
tap the side of the pan 10 times).
should see the following:
The water will work its way to the
surface, flooding the area around the
The houses will start leaning over and
sinking into the sand.
The volume of the sand should decrease
by a small amount. Note where the
surface is after shaking in relation
to the mark denoting the surface
Try the experiment using clay or gravel
to separate sand layers and represent
different types of sedimentary layers.
Watch what happens to the water and the
surface of your model of a river valley.
Compare what happens to the water when
using different materials.
Courtesy of Ohio Division of
Geological Survey "HANDS ON EARTH
SCIENCE" Webpage. Modified by
the California Geological Survey.
Earth Connections No. 2, published in
Washington Geology, v. 27, no. 2/3/4,
December 1999, Washington Division of
Geology and Earth Resources.
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