Travel Reference
In-Depth Information
Scientists monitor
the
movement of the San Andreas
Fault by bouncing laser beams off
a network of reflectors. The system
can pick up movements of less
than 0.025 inch (0.6 mm) over a
distance of 4 miles (6 km), enabling
seismologists to predict when
earthquakes are likely to occur.
The hills and coastal ranges
of the Bay
Area are pressure ridges formed by
hundreds of fault movements
compressing and uplifting the land.
Hayward
Fault
In Oakland
, 42 people were killed in 1989 when an
elevated highway section collapsed and 44 slabs of
concrete, each weighing 661 tons, fell onto the cars.
A vibroseis truck
produces
artificial S (secondary)
waves that probe
the underlying rock
structure to measure
movement.
Calaveras
Fault
1872
Earthquake demolishes town of Lone
Pine and Sierra Nevadas rise 13 ft (4 m)
1890
Pronounced earth tremor
1769
Members
of Portolá's expedition
are first Europeans
to experience an
earthquake in California
1989
Loma Prieta earthquake strikes city
and Bay Area, killing 67 and making 1,800
homeless. Worst quake since 1906
1957
Strong tremor in Bay Area
1857
Strong earth tremor
followed by smaller
tremors in Bay Area
1750
1800
1850
1900
1950
1865
City suffers its first major earth-
quake on October 9, followed by
second quake on October 23
1977
8 earth tremors occur
1906
Strongest earthquake ever; 3-day fire
destroys much of city leaving 3,000 dead and
250,000 homeless. 52 small tremors shake
region over following two days
Don Gaspar
de Portolá
1868
Strong tremor in
Hayward Fault
1906 earthquake
damage
