Last lecture

Historical behavior of San Andreas fault

We’ve looked at only a few of the interesting historical earthquakes!

Meade and Hager [2005]

34±3 mm/a

3,700 a

25±3 mm/a

5,900-14,500 a

16±3 mm/a

5,900-14,500 a

Lecture 21: The San Andreas fault

Neotectonic overview (continued)

• Loma Prieta 1989

• The San Gorgonio Pass jog

San Andreas fault

Uplift rates between 0.13 and 0.35 mm/a

Nominal Loma Prieta earthquakes every 300-600 years

442 earthquakes to produce the 125,000-year terrace

San Gorgonio Pass stepover

What are the actual kinematics?

The first step in answering this question is to understand the 3-D geometry of the fault system

What is happening in the San Bernardino Mountains?

Where are the active structures on the san Gorgonio Pass side of the San Bernardino mountains?

Active faults and topo of the region

1986 eq

Broad antiformal warps

Contours on base of seismicity