The Loma Prieta earthquake occurred on October
17, 1989, in the greater San Francisco Bay Area in California at
5:04 p.m. local time and measured 6.9 on the Moment magnitude scale
(surface-wave magnitude 7.1). It occurred during the 1989 World
Series, which happened to match up the Bay Area's two Major League
Baseball teams, the Oakland Athletics against the San Francisco
Giants. The earthquake lasted for 15 seconds. Its epicenter was at
geographical coordinates 37.04° N 121.88° W south-southwest of Loma
Prieta Peak in the unincorporated area of Aptos. This location, in
the Santa Cruz Mountains' Forest of Nisene Marks State Park, is
about ten miles (16 km) northeast of the city of Santa Cruz,
California. The focus point was at a depth of 16.79 km, or 10
miles.
The Loma Prieta was a major earthquake, and
caused severe damage as far as 50 miles away from its epicenter;
most notably in San Francisco, Oakland, the San Francisco
Peninsula, and in areas closer to the epicenter in the communities
of Santa Cruz, the Monterey Bay, Watsonville, and Los Gatos. Most
of the major property damage in the more distant areas resulted
from liquefaction of soil used over the years to fill in the
waterfront and then built upon.
The magnitude and distance of the earthquake from
the severe damage to the north were surprising to geotechnologists.
Subsequent analysis indicates that the damage was likely due to
reflected seismic waves - the reflection from well-known deep
(about 15 miles) discontinuities in the Earth's gross
structure.
There were 57 deaths directly caused by the
earthquake, and six more deaths were ruled to be indirectly caused
by the temblor[1]. In addition, there were 3,757 injuries as a
result of the earthquake. The highest concentration of fatalities,
42, occurred in the collapse of the Cypress Street Viaduct on the
Nimitz Freeway (Interstate 880), where a double-decker portion of
the freeway collapsed, crushing the cars on the lower deck. One
50-foot (15 m) section of the San Francisco-Oakland Bay Bridge also
collapsed, causing two cars to fall to the deck below, leading to
the single fatality on the bridge. The bridge was closed for
repairs for a month and one day, reopening on November 18. While
the bridge was closed, ridership on Bay Area Rapid Transit and
ferry services soared, along with traffic levels on nearby bridges
such as the Richmond-San Rafael and the Golden Gate.
The quake also caused an estimated $6 billion in
property damage, the costliest natural disaster in U.S. history at
the time. It was the largest earthquake to occur on the San Andreas
Fault since the great 1906 San Francisco earthquake. Private
donations poured in to aid relief efforts and on October 26,
President George H.W. Bush signed a $3.45 billion earthquake relief
package for California.
The Loma Prieta earthquake irrevocably changed
the San Francisco Bay Area's transportation landscape. Not only did
the quake force seismic retrofitting of all San Francisco Bay Area
bridges, it caused enough damage that some parts of the region's
freeway system had to be demolished. In some cases, the freeways in
question had never been completed, terminating in mid-air; in that
regard, the quake provided the impetus to deal with regional
transportation problems that had gone largely unsolved for
decades.
An automobile lies crushed under the third
story of this apartment building in the Marina District. The ground
levels are no longer visible because of structural failure and
sinking due to liquefaction.
Quiz
A. What was the date of the quake? mmddyyyy
B. What time did the quake hit? (ignore colon hmm)
C. What was the north coordinates of the epicenter?
D. The west coordinates?
E. How deep was the focus point?
F. How many deaths were caused by the quake?
G. How many injuries?
H. What interstate collapsed? (three numbers: Interstate ...)
I. How many meters of the bay bridge collapsed?
J. What day did the bridge reopen? (mmdd)
K. How many years ago was the quake? (as of Oct. 17, 2009)
L. What was the estimated property damage loss? x billion (single
digit answer)
Cache hidden at: N LO°MA.PRI W ETA°QU.AKE
L= H÷K-K-L-I
O= B÷K-I-2.2
M= AG÷C. Multiply by zero.
A= K-E-E
P= B÷K-I-3.2
R= E+K-I-E
I= E÷L. Round up to whole number.
E= ACG÷C÷G÷A
T= (E+K) ÷I
A= K-I-3
Q= F÷I-.8
U= G-H-J-1757
A= L+H-878
K= (F-E+I) ÷L-L. Round down to whole number.
E= H÷F+J÷B+K-I-5. Round down to whole number.
You can check your answers for this puzzle on
Geochecker.com.
You can validate your puzzle solution with certitude.
Information found at this address:
http://naturesmightypictures.blogspot.com/2006/11/loma-prieta-earthquake-1989.html