The animations below were developed
by EdCenter Staff Scientist Jeff Sale for the educational video "Written
in Stone" produced by San Diego State professor Pat Abbott. This
project was funded by and developed for the California Seismic Safety
Commission.
These animations offer visual
explanations for some of the more complex processes involved in earthquake
dynamics. They also include some practical mitigation procedures for securing
one's home for protection during an earthquake.
| Animation
of Rayleigh Waves: Rayleigh Waves are the most damaging
waves caused by earthquakes. This animation illustrates the reverse
elliptical dynamics underlying Rayleigh Waves that cause such intense
shifting during an earthquake. |
|
| How
to Brace an Unsecured Cripple Wall: many houses have
a cripple wall supporting them which provides a crawl space underneath
the house. However, unsecured cripple walls can easily collapse during
an earthquake. This animation provides a brief overview of basic methods
for securing a cripple wall. |
|
| San
Andreas Shifts: this animation demonstrates the relationship
between earthquake magnitude and fault movement. Small earthquakes
emit mainly fast-moving high-frequency waves, whereas large earthquakes
not only emit high-frequency waves but also low-frequency slow-moving
waves. |
|
| Chimney
Failure and Bracing: this animation illustrates the collapse
of an unreinforced brick masonry chimney, and proper methods for structural
reinforcement. |
|
| Lake
Elsinore Sequence: this animation illustrates the creation
of Lake Elsinore due to fault shifting. |
|
| Signal
Hill Sequence: this animation illustrates a fault bend
pushing up the ground between the faults to form a hill, in this case
one similar to Signal Hill in the Los Angeles region. |
|
| Seismic
Propagation: this animation illustrates how seismic waves
move more rapidly with lower amplitude through hard dense rock as
opposed to soft sediment. |
|
| Northridge
2D Earthquake Fault Movement: this animation illustrates
the "blind thrust" fault of the 1994 Northridge earthquake. |
|
| Landers
Earthquake: this animation illustrates the multi-fault
nature of the 1992 Landers earthquake and demonstrates the advanced
computational simulation of the underlying seismic dynamics created
by Prof. Kim Olsen of San Diego State University. |
|
| San
Andreas 265-mile-wide rupture: this animation illustrates
the 250-mile-wide extent of the 1906 rupture of San Andreas fault
in northern california. |
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