Geography Reference
In-Depth Information
most famous of these is the San Andreas fault on the Pacific coast, where the Pacific plate is heading north
and rubbing against the Atlantic plate, taking part of the California coast with it. Contrary to popular be-
lief—and perhaps some wishful thinking on the part of anti-Californians—California is not destined to
slide into the Pacific Ocean. Instead, it will be dragged, kicking and screaming, to the north. Computer
projections plotting the location of the plates in fifty million years, at present rates of movement, put Los
Angeles in the vicinity of Anchorage. Just think of it. La-La, Alaska. In the slightly shorter term, the res-
ults may be equally interesting, as Jonathan Weiner put it in his topic
Planet Earth.
“In 15 million years,
Los Angeles, if it still exists, will be a suburb of San Francisco. The Giants and the Dodgers will again be
crosstown rivals.”
In the immediate short-term future, the outlook is not amusing. The earthquake that struck San Fran-
cisco and Oakland in October 1989 was graded at 7.1 on the Richter scale, a major earthquake capable of
inflicting serious damage. Most seismologists believe that California is due for a larger earthquake, per-
haps in the 8 or 9 range, which is as high as the Richter scale goes. Devised in the 1940s by seismolo-
gists Charles Richter and Beno Gutenberg, the Richter scale measures the amount of energy released by an
earthquake and the potential for damage.
The Richter Scale
Effects
Average Number Per Year
under 2
Imperceptible
600,000
2.0 to 2.9
Generally not felt
300,000
3.0 to 3.9
Felt by people nearby
49,000
4.0 to 4.9
Minor shock; slight damage
6,000
5.0 to 5.9
Moderate shock; energy equi-
valent to an atomic bomb
1,000
6.0 to 6.9
Large shock; can be destruct-
ive in populous areas
120
7.0 to 7.9
Major earthquake; inflicts ser-
ious damage; recorded world-
wide
14
8.0 to 8.9
Great earthquake producing
total destruction to nearby
communities; energy released
is a million times the first
atomic bomb
One every 5 to 10 years
9.0 or more
Largest earthquakes
One or two per century
Major Historical Earthquake Disasters
365—Eastern Mediterranean
Affecting an area of about a million square miles—encompassing
Italy, Greece, Palestine, and North Africa—this earthquake leveled coastal towns, and the huge
wave it spawned destroyed the Egyptian city of Alexandria, drowning 5,000 people there.
1556, January 24—Shaanxi (Shensi) Province, China
In the most deadly earthquake in history,
an estimated 830,000 people were killed.
