Natural Disasters: Earthquakes & Volcanoes

An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. The moment magnitude of an earthquake is conventionally reported, or the related and mostly obsolete Richter magnitude, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.

At the Earth's surface, earthquakes manifest themselves by a shaking and sometimes displacement of the ground. When a large earthquake epicenter is located offshore, the seabed sometimes suffers sufficient displacement to cause a tsunami. The shaking in earthquakes can also trigger landslides and occasionally volcanic activity.

In its most generic sense, the word earthquake is used to describe any seismic event—whether a natural phenomenon or an event caused by humans—that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, huge amounts of gas migration, mainly methane deep within the earth, but also by volcanic activity, landslides, mine blasts, and nuclear experiments.

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.

Volcanoes are generally found where tectonic plates are pulled apart or come together. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by "divergent tectonic plates" pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by "convergent tectonic plates" coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust, such as in the African Rift Valley, the Wells Gray-Clearwater Volcanic Field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

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22 Items found Print
All About Volcanoes & Earthquakes
All About Books #4
by Frederick H. Pough
from Random House
for 3rd-6th grade
in All About Books (Location: VIN-ALL)
Discovering Volcanoes
by Nancy Field & Sally Machlis
from Dog-Eared Publications
for 4th-6th grade
in Clearance: Science & Health (Location: ZCLE-SCI)
$1.50 (1 in stock)
Earthquake at Dawn
by Kristiana Gregory
from Gulliver Books
Historical Fiction for 5th-8th grade
in Historical Fiction (Location: FIC-HIF)
$3.50 (1 in stock)
Earthquakes
by Trudi Strain Trueit
from Franklin Watts
for 3rd-6th grade
$4.50 (1 in stock)
Eyes on Adventure: Exploring Natural Disasters
Eyes on Adventure
by Stella Sands
from KidsBooks, Inc.
for 4th-6th grade
$2.00 (3 in stock)
Footprints in the Ash
by John Morris, Steve Austin
from Master Books
for 10th-Adult
in Clearance: Christian Books (Location: XCLE)
$5.00 (1 in stock)
Great East Japan Earthquake and Tsunami
from kahoku Shimpo Publishing Co
for 1st-Adult
in Japan (Location: HISMC-JAP)
$10.00 (1 in stock)
Janice VanCleave's Volcanoes
Janice VanCleave's Science
by Janice VanCleave
from John Wiley & Sons, Inc.
$6.50 (2 in stock)
True Book: Volcanoes
A True Book
by Elaine Landau
from Scholastic Inc.
for 3rd-5th grade
$3.00 (1 in stock)
Volcano
by Patricia Lauber
from Trumpet Club
for 4th-8th grade
$3.00 (2 in stock)
Volcano
by Patricia Lauber
from Simon and Schuster
for 3rd-6th grade
1987 Newbery Honor Book
$9.99 $6.00 (4 in stock)
Volcano
by Patricia Lauber
from Bradbury Press
for 4th-7th grade
$12.00 (1 in stock)
Volcano!!
by Scott C.S. Stone
from Island Heritage Publishing
for 3rd-6th grade
$2.00 (1 in stock)
Volcanoes
Let's-Read-and-Find-Out Science Stage 2
by Franklyn M. Branley, illustrated by Marc Simont
from HarperCollins
for Kindergarten-3rd grade
$3.00 (1 in stock)
Volcanoes
by Phillippe Bourseiller
from Harry N. Abrams, Inc.
for 4th-Adult
in Oversized Science Books (Location: SCI-OVER)
$6.00 (1 in stock)
Volcanoes
by Seymour Simon
from Smithsonian Books
for Kindergarten-2nd grade
$4.00 (1 in stock)
Volcanoes and Other Forces of nature: A LEGO Adventure in the Real World
for Kindergarten-2nd grade
$4.50 (1 in stock)
Volcanoes!
A Step into Reading Book Level 4
by Eric Arnold
from Random House
for 2nd-3rd grade
in Step into Reading (Location: EAR-STEP)
$5.99
Volcanoes: Run For Your Life!
Scholastic Discover More Readers Level 3
by Laaren Brown
from Scholastic Inc.
for 1st-3rd grade
in Early Readers (Location: EAR-MISC)
What Was Pompeii?
by Jim O'Connor
from Grosset & Dunlap
for 2nd-6th grade
in Ancient Rome (Location: HISW-ANRO)
$4.00 (1 in stock)
Why the Earth Quakes
by Julian May, illustrated by Julian Everett Fisher
from Holiday House
for 1st-3rd grade
in Vintage Science & Math (Location: VIN-SCI)
$12.00 (1 in stock)
You and the Earth Beneath Us
by Julian May, illustrated by Beth Wilson
from Children's Press
for 3rd-6th grade
in Vintage Science & Math (Location: VIN-SCI)
$14.00 (1 in stock)