PowerPoint presents 2 Earthquake case studies in America Loma Prieta (1989) San Francisco Earthquake (1906)

1. San Andreas Fault
1989 Loma Prieta
1906 San Francisco earthquake
By Owen, Lorenz, Harry and
Callum the Cuspate Foreland

2. At transform boundaries, tectonic plates are not moving directly toward or
directly away from each other. Instead, two tectonic plates grind past each
other in a horizontal direction. This kind of boundary results in a fault — a
crack or fracture in the earth's crust that is associated with this movement.
Transform Boundaries

3. Faults and Earthquakes
Transform boundaries and the resulting faults
produce many earthquakes because edges of
tectonic plates are jagged rather than smooth. As
the plates grind past each other, the jagged edges
strike each other, catch, and stick, "locking" the
plates in place for a time. Because the plates are
locked together without moving, a lot of stress
builds up at the fault line. This stress is released in
quick bursts when the plates suddenly slip into new
positions. The sudden movement is what we feel as
the shaking and trembling of an earthquake.

4. Loma Prieta
On October 17, 1989, at 5:04 p.m.
A magnitude 6.9 earthquake severely shook the
San Francisco and Monterey Bay regions.
The shock was centered in The Forest of Nisene
Marks State Park approximately 16 km northeast
of Santa Cruz on a section of the San Andreas
Fault System

5. Loma Prieta- Pictures

6. San Francisco Earthquake
7 Years (great song by Lukas Graham) after Loma Prieta occurred,
San Francisco had another earthquake.
The 1906 San Francisco earthquake struck the
coast of Northern California at 5:12 a.m. on
April 18 with an estimated moment magnitude of
7.8

8. http://www.history.com/topics/san-francisco/videos/mega-disasters-
san-francisco-earthquake
Severe shaking was felt from Eureka on the North Coast to
the Salinas Valley, an agricultural region to the south of
the San Francisco Bay Area.
Devastating fires soon broke out in the city and lasted for
several days. As a result, about 3,000 people died and over
80% of the city of San Francisco was destroyed.
The events are remembered as one of the worst and
deadliest natural disasters in the history of the United
States. The death toll remains the greatest loss of life from
a natural disaster in California's history and high in the
lists of American urban disasters.