Environmental Engineering Reference
In-Depth Information
HAWAII
ALASKA
KALIAI
1
1
0
NIIHAU
MOLOKAI
MAUI
OAHU
2
2
LANAI
3
KAHOOLAWE
3
HAWAII
1
1
1
1
3
1
GA
MIIS
LA
Intensity
X up
IX-X
VIII - IX
VII - VIII
FLA
M E
O F
Maximum acceleration
g (%)
Zone
M
3 (near a great fault)
3 (not near a great fault)
2
1
0
50
33
16
8
4
8.5
7.0
5.75
4.75
4.25
Source : From Housner, G.W.(1965).
FIGURE 11.3
Seismic risk zones and location of damaging earthquakes in the United States through 1966. See table above for
significance of zones. Compare with Figure 11.13. (Map prepared by the U.S. Geological Society.)
Apartment buildings in the San Francisco, Marina District, collapsed and burned, a portion
of the Oakland Bay Bridge separated and the upper deck fell onto the lower roadway, and a
two-level elevated structure of highway I-880 collapsed. Of particular interest was the lack
of surface rupture. Instrumentation showed that the Pacific Plate slipped 2 m northwest past
the North American Plate ( Figure 11.1) and rode upward about 1 m.
Northridge, Los Angeles, California : January 17, 1994, M
6.7, occurred along an unknown,
buried (blind) thrust fault. Apartment buildings, concrete parking garages, and ten high-
way bridges collapsed, and 60 deaths were recorded.
Pymatuning Reservoir, Pennsylvania: September 25, 1998, M
5.2, was the last significant
earthquake to have occurred in the northeastern U.S. (Geotimes [2001], excerpted from
USGS Fact Sheet FS-006-01.” Earthquakes in and near the northeastern U.S., 1638-1998.”)
Damage was minor and no deaths or injuries were reported.
 
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