Transforming California

Landforms of the San Andreas Fault

Images & text by Thomas McGuire, Cave Creek Digital, Cave Creek, AZcavecreekdigital@msn.com

“If we intend to live on this planet… we truly need to understand how it works.”

Exploring ways to find fault…

3The author at Parkfield CA, site of USGS seismic experiment. “Be here when it happens!”

4

Fault Issues1. Fault Scarps & Alignments2. Sag Ponds3. Offset Drainages4. Distortion of Human-Made Structures5. Infrastructure Vulnerability

5

Basic

California

Geography

ImperialValley

Los Angeles

Mojave Desert

San

Joaquin

Valley

San Francisco

San

Andreas

Fault

Death Valley

6San Andreas Lakes viewed from the south near San Jose

7

The San Andreas fault is part of the boundary between the North American and Pacific tectonic plates. It is classified as a right lateral transform fault.

(To a person facing the fault,

the far side shifts to the right.)

Our Dynamic Earth, Robert Tilling, USGS, 1996

8The Sea of Cortez.. (Known to Gringos as The Gulf of California.)

9The US-Mexican Border (fence line) is as impervious to plate processes as it is to immigration.

10The All-American Canal brings Colorado River water to the Imperial Valley of California.

11Wind Farm north of Palm Springs near San Gorgonio Pass.

12The main trace of the fault runs NE of Los Angeles, but numerous splay faults affect the LA Basin.. (So does smog.)

13California Aqueduct at Palmdale, north of Los Angeles.

14Gates along the California Aqueduct at Palmdale

15San Andreas Fault road cut, CA 14 at Palmdale,

16Detail of CA 14 road cut at Palmdale

17Intersection of the San Andreas & Garlock Faults east of Tejon Pass.

18John Marquis, USC

The

San

Andreas

and

Garlock

Faults

19Remains of Manzanar Japanese American internment Camp (WWII) and the steep eastern front of the Sierra Nevada Mountains

20

Columnar jointing in basalt

at Devil’s Postpile near

Mammoth Lakes, CA

21

Top of jointed basalt columns, Devil’s Postpile, CA

22Dante’s View, Death Valley, CA. Badwater, at -282 Ft, the lowest place in the Western Hemisphere, is at the bottom right.

23

24San Andreas Fault, Carrizo Plain just north of CA 166.

25

Fence (see last slide) crosses San Andreas Fault near CA 166.

26San Andreas Fault ridge, Elkhorn Scarp along the base of the Tremblor Range, Carrizo Plain, CA

27Fault trace, Carrizo Plain, CA

28San Andreas Fault, Carrizo Plain, CA

29Stream offset along the San Andreas Fault, Carrizo Plain, CA

30Soda Lake, Carrizo Plain,. A closed drainage (sag pond) feature.

31

Wallace Creek, USGS aerial view, about 1990 USGS Photo

32

Wallace Creek fault investigation area on the Carrizo Plain. Numbers show signed posted nature trail features. Next image at #1..

33Tom at Wallace Creek fault offset .

34Stream offset along the San Andreas Fault near Wallace Creek, CA

35Stream offset north of the Carrizo Plain, on Bitterwater Road.

36Sag pond, San Andreas Fault along CA 25.

37San Andreas cable crossing & sag pond, CA Route 25.

38

Sheared tree limbs along CA, Route 25

; )

39San Andreas Fault trace, CA Route 25.

40California Route 25 along the San Andreas Fault.

41Pressure Ridge, California Route 25.

42San Andreas fault scarp & sag pond just east of California Route 25.

43Slump structure near the San Andreas Fault, California Route 25.

44Parkfield, CA. USGS seismic experiment center.

45Laser triangulation and GPS site, Parkfield, CA

46Bridge across San Andreas Fault at Parkfield

47

San Andreas Fault right lateral offset at Parkfield Bridge

48San Andreas Fault Movement, DeRose Winery, Hollister, CA Note the new building at the top left.

49

28 years of offset at the Cienga Winery, USGS Photo TMcG

50New construction & fault trace, June 2003, DeRose Cienga Winery. The offset ditch runs barely out of sight on the right.

51

San Andreas fault creep damage

De Rose Cienga Winery, south of Hollister CA

52Town of Hollister, California viewed from the Calaveras fault scarp. The San Andreas fault runs sub-parallel l,.5 miles west.

53Wall on 6th Street distorted by Calaveras Fault creep (June 2003)

54

Rotational Translation on 6th Street

55

Offset curb,

6th Street

Hollister

56

Offset curb

on,7th Street

57Roof damage, Hollister High School

58

Discrepant Event, Hollister ; )

595th Street, Hollister.

60

5th Street

Detail #1

61

5th Street

Detail #2

625th Street Detail #3

634th Street front steps..

64Displaced sidewalk, 359 Locust Avenue, Hollister

65Retaining wall, 359 Locust Avenue, Hollister.

66

Locust Avenue Garage

& power pole.

Garage built in 1929

67

Locust

Avenue

Curb &

utilities

68USGS, Menlo Park (Bay Area) Research Center

69

The San

Andreas Fault

passes a few

kilometers west

(left) of the

Golden Gate

Bridge.

San Francisco Tourism Photo

70Bye bye to the fault! (Point Reyes)

71Seismology & economics converge

72

The

End. USGS map

California

Transformed