Laboratory Manual for Introductory Geology 4e

EXERCISE 11.7
Locating Liquefaction Potential (continued)
Name:
Course:
Section:
Date:
The map on the left below shows locations susceptible to liquefaction as well as historical liquefaction events in the
San Francisco area during the 1906 and 1989 earthquakes. Some of the 1989 events were in the same area as those of
1906, but several new areas were affected.
(b) Compare the locations of the 1989 liquefaction events with the water table elevations in the previous diagram.
Does the relationship between liquefaction and water table elevation you discovered in question (a) also apply to
all of these areas? If not, suggest possible explanations for the difference.
(c) Now look at the locations of the 1989 liquefaction events that occurred in places not affected by the 1906 earthquake.
(i) Are they randomly distributed throughout the region or restricted to specific locations? Explain.
(ii) Are they located in areas of varied susceptibility to liquefaction or in areas with the same level of susceptibility?
Explain.
(iii) Compare the 1989 liquefaction sites with the map of shoreline changes on the right below. Why did the 1989
earthquake affect these areas, but not the 1906 earthquake?
Dots show liquefaction sites during the 1906 and
1989 earthquakes. Shading shows the degree of
susceptibility to liquefaction.
Shoreline changes in the San Francisco area. Pink shading
shows landfill added since the 1906 earthquake.
1906
1989
0 3
km
mi
0 2
(continued)