ADJUSTMENT OF TRILATERATION FOR FAULT MONITORING

ONE OF THE MAJOR AND TECTONICALLY MOST ACTIVE EARTHQUAKE FAULT ZONES IN THE UNITED STATES IS THE SAN ANDREAS FAULT SYSTEM OF CALIFORNIA. IN RECENT YEARS VARIOUS ORGANIZATIONS HAVE BECOME ENGAGED IN RESEARCH AND MEASUREMENTS ALONG THIS FAULT SYSTEM, SEEKING TO FURTHER MAN'S KNOWLEDGE OF EARTHQUAKES. ONE OF THESE RESEARCH PROGRAMS NOW IN PROGRESS IS GEODIMETER TRILATERATION. THIS PROGRAM WAS BEGUN IN 1959 BY THE CALIFORNIA DEPARTMENT OF WATER RESOURCES TO OBTAIN VITAL FAULT MOVEMENT INFORMATION NEEDED FOR PLANNING AND DESIGNING THE AQUEDUCT SYSTEM. THIS STUDY ALSO INDICATED, HOWEVER, CORRELATION BETWEEN FAULT MOVEMENT RATES AND RECORDED EARTHQUAKES. THIS SUGGESTED THAT CONTINUED MEASUREMENTS OF FAULT MOVEMENTS MIGHT PROVIDE AN EFFECTIVE EARTHQUAKE WARNING SYSTEM. GEODIMETER TRILATERATION HAS BEEN CONTINUED BY THE CALIFORNIA DEPARTMENT OF CONSERVATION AND CURRENTLY INVOLVES PRECISE MEASUREMENTS USING A LASER GEODIMETER. SOME MEASURED LINES MERELY CRISS-CROSS THE FAULT AND ARE INDEPENDENT OF ANY OTHER LINES. OTHER MEASURED LINES ARE PART OF CLOSED GEOMETRIC FIGURES WHICH ENABLE LEAST SQUARES ADJUSTMENT AND THE EVALUATION OF MEASUREMENT PRECISIONS. THIS PAPER DISCUSSES THE ADJUSTMENT OF PRECISE LASER GEODIMETER MEASUREMENTS OF A FIVE-POINT FIGURE LOCATED NEAR HOLLISTER IN THE TECTONICALLY ACTIVE AREA AT THE JUNCTION OF THE HAYWARD-CALAVERAS AND SAN ANDREAS FAULTS. /AUTHOR/

• Supplemental Notes:
  • pp 435-451, 4 FIG, 3 TAB
• Authors:
  • Wolf, P R
• Publication Date: 1971-3

Media Info

• Serial:
  • Surveying and Mapping
  • Publisher: American Congress on Surveying and Mapping

Subject/Index Terms

• TRT Terms: Earthquakes; Faults; Lasers; Measurement; Motion; Warning systems
• Old TRIS Terms: Geodimeters; Geological faults; Trilateration
• Subject Areas: Design; Highways;

Filing Info

• Accession Number: 00202927
• Record Type: Publication
• Report/Paper Numbers: pp 782-785
• Files: TRIS
• Created Date: Aug 8 1971 12:00AM