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The Parkfield-Cholame California, Earthquakes of June-August 1966

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The Parkfield-Cholame California, Earthquakes of June-August 1966 The Parkfield-Cholame California, Earthquakes of June-August 1966 GEOLOGICAL SURVEY PROFESSIONAL PAPER 579 The Parkfield-Cholame California, Earthquakes of June-August 1966 Surface Geologic Effects Water-Resources Aspects, and Preliminary Seismic Data By ROBERT D. BROWN, JR., J. G. VEDDER, ROBERT E. WALLACE, EDWARD F. ROTH, R. F. YERKES, R. O. CASTLE, A. O. WAANANEN, R. W. PAGE, and JERRY P. EATON GEOLOGICAL SURVEY PROFESSIONAL PAPER 579 Results of detailed studies of a moderate magnitude earthquake and its aftershocks A contribution of the National Center for Earthquake Research of the Geological Survey UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1967 UNITED STATES DEPARTMENT OF THE INTERIOR STEW ART L. UDALL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price 50 cents (paper cover) CONTENTS Page Page Abstract-_----__---____-____-_-_-_-_____-__-_-____. 1 Engineering geology aspects, by R. F. Yerkes and R. O. Introduction, by Robert D. Brown, Jr________-____-__- 1 Castle------_--__--.__.___--_-.___-___.____.___ 40 Surface tectonic fractures along the San Andreas fault, Effects--------.__--------------_-------___---- 41 by Robert D> Brown, Jr., and J. G. Vedder._________ 2 Primary effects on terrain..__________________ 41 Relation of the earthquakes to ground breakage.___ 2 Secondary effects on terrain._________________ 41 San Andreas fault zone._________________________ 3 Primary effects on manmade structures.--_____ 46 Geology _ ___-________--_-_-__----__-_____------ 4 Secondary effects on manmade structures._____ 48 Historical earthquakes accompanied by surface Effects on loose objects._____________________ 49 fracture. ____________________________________ 9 Miscellaneous effects._______________________ 50 Methods of study__-__-__-----_-____-__---______ 10 Inferred intensity-______________________________ 51 Fracture zones-___--___-_-_--_____-__---_-____-_ 11 Conclusions and implications.____________________ 52 General relations.___________________________ 11 Water-resources aspects, by A. 0. Waananen and R. W. Main fracture zone.________-_._____---______ 13 Page--------.-__-----_------_-------______---- 53 Southwest fracture zone.____________________ 13 Water-surface fluctuations in June 1966__________ 53 Types of fractures._________________________ 13 Fluctuations in ground-water levels.______________ 54 En echelon fractures.___________________ 13 Effect on quality of water..______________________ 56 Linear fractures._______________________ 15 Conclusions-____._---____-____________._____--- 56 Other types of ground cracks.____________ 15 Instrumental seismic studies, by Jerry P. Eaton.---____ 57 Other criteria for locating tectonic fracturing. __ 17 Results from the Gold Hill seismograph.___________ 57 Significance of surface tectonic fractures_______-._. 22 Preearthquake seismic activity --------------- 57 Rates and patterns of progressive deformation, by Robert Relations between foreshocks, main shock, and E. Wallace and Edward F. Roth...._______-_----.__ 23 aftershocks.______________________________ 57 Deformation related to 1966 earthquakes. _________ 23 Frequency of aftershocks.___________________ 58 Dimensional changes of quadrilaterals.________ 23 Record of intense ground motion. ____________ 60 Displacements measured on roads.____________ 32 Geometry of the aftershock source region southeast Progressive development of en echelon cracks of Gold Hill_.-__-----__-_--_----------------_ 62 and mole tracks._________________________ 33 Seismic-refraction calibration of the crust in the Historic deformation prior to 1966_-_____--_--____ 33 aftershock region..___________________________ 65 Precursory events.-_____________________________ 37 References cited-____-------_-________-_____________ 65 ILLUSTRATIONS Page FIGURE 1. Index map showing a part of the San Andreas fault zone and the location of the Parkfield-Cholame area. 4 2. Map showing location of tectonic fracture zones and points used for strain measurement.... ... ________ 6 3. Generalized geologic map of Parkfield-Cholame area. ___________-_____________--------_----_------ 8 4-7. Photographs showing: 4. Landslide fissure produced by the Parkfield earthquake of June 7, 1934----------------------- 10 5. Tectonic fractures, main fracture zone____________________________________________________ 12 6. En echelon fractures, southwest fracture zone._____________________________________________ 14 7. En echelon fractures in surfaced county road from Highway 46 to Parkfield. __________________ 14 8. Diagram of en echelon and linear fractures southeast of Highway 46_____________----__-------_--_-- 15 9. Maps of en echelon fractures in asphalt across Parkfield road and across Meng road___-------------- 16 10. Map of en echelon fractures in fine sandy, silt---------------------------------------------------- 17 11. Photographs showing evidence of strike slip, main fracture zone_________________--__--_---__------- 18 12. Sketch map of en echelon fractures and accompanying mounds or pressure ridges_____________________ 19 13- Photograph showing nearly vertical en echelon fracture, left bank of Cholame Creek. 20 14. Photographs showing^features associated with tectonic fracture zones____________--__-________------------ 21 in IV CONTENTS Page FIGURE 15. Geometry for determing strike-slip component from dimensional changes of quadrilateral._-_-__--__--_-._____ 23 16. Plan of quadrilaterals QA and QB and graph of dimensional changes with time______________________________ 24 17. Detailed map of tectonic fracture zone at quadrilaterals QA and QB_ ______________________________________ 26 18. Plan of quadrilateral QD and graph of dimensional changes with time______________________________________ 30 19. Profile along Cholame-Parkfield road_.____-___-___________-_---------__-----------__________________.__ 31 20. Graph showing relative change in elevation, Cholame-Parkfield road_--_-__-_------_---____________________ 32 21. Diagram of suggested linkage between two en echelon segments. __________________________________________ 33 22-24. Plans of quadrilaterals and graphs of dimensional changes with time: 22. Quadrilateral QF_______._____.____________--__----------__-__-----------_-______-____.______ 34 23. Quadrilateral QJ______________________________-----_-_----_-__----_---_---____-_._____________ 35 24. Quadrilateral QI_____-___________________-__----_-.---------__----------_-____-----___________ 36 25. Graph of offset of center white line on Highway 46- _----_-----------------------------------------_-____ 37 26. Photographs of the white centerline on Highway 46_______----___-_______________________________________ 37 27. Map of fractures in Highway 46__._____________-_______--_--____---__-_____-_-_---_-__________________ 38 28-32. Photographs: 28. Growth of fracture__-________________________--------_-_-__--_--------__-_.__________________ 38 29. Fracture showing relief _______-_________-______-----_-__--_----------__---___-_________._.____ 39 30. Relief across fracture zone_____-______________---_--_---_-_--------_--_---___-___..____________ 39 31. Along Claassen fence _-__________________________-_-__----_-___-___-___---___-_____-__________ 39 32. Along fence at locality F23 ------------------------------------------------------------------- 40 33- Diagrammatic plan showing misalinement of I-beam___-___-_--_----_--_-__-____----____--________-_-____ 40 34. Photograph of fractures taken June 16, 1966_________-_______---------_------_--_---_-_---___--_-___--_- 41 35. Map showing distribution and types of effects that accompanied the earthquakes.___-_-_-_____-__.._________-. 42 36. Sketch map and photograph showing block glide inside of meander.________-_-__------__--___-___-._-__._. 44 37. Photographs showing debris slides.____________________________________________________________________ 45 38. Map of area between fracture zones about 2 miles south of Parkfield_--__--_---_-_----.-_________-____-____ 46 39-41. Photographs showing: 39. View southward of new fissures within a reactivated slump ----__--___-_____-_-________-._-___-____ 46 40. View northwest of swimming pool at Miller's house_____-___--___-__-__-_-____--_________-_-______ 46 41. Deposit of dust and silt ejected by air near main fracture zone..____________________________________ 47 42. Schematic plan showing deformation of Monterey County road bridge (No. 438) ____________________________ 47 43-47. Photographs showing: 43. Selected examples of damaged chimneys_ _______________________________________________________ 48 44. Broken and expanded unreinforced adobe brick wall attached to frame house ._______________________ 49 45. Deformation of Monterey County road bridge (No. 444)____-___------__-----__.___-___________-___ 50 46. Damaged concrete bridge abutment, east end of Highway 46 bridge..________________________________ 50 47. Collapsed or projected heavy objects ______-__________-__---____-___--_-----___-__--____--______ 51 48. Map and photograph showing irrigation pipeline that crosses main fracture zonc.-_._--_._____-________-.____ 52 49. Map of selected gaging stations, observation wells, and compaction-recorder sites-----___..___-____-__________ 55 50-52. Graphs showing: 50. Fluctuations recorded at gaging stations and an observation well __________-----____-__--____-_-_-_. 56 51. Frequency of aftershocks at Gold Hill_ ________-_____---_-_-___-_--_-------_---___--______-_-___
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