Bulletin géodésique

, Volume 88, Issue 1, pp 151–157 | Cite as

The use of a laser extensometer to observe strain in a large ground sample

  • V. Vali
  • R. C. Bostrom
Article

Abstract

The design and construction are described of an experimental strainmeter. This observes changes in the number of waves of light standing in a one-kilometer gap between points on the earth’s surface. Strain is observed over a frequency range of zero to several hundred hertz, to an accuracy of an arbitrarily-small fraction of a wave-length of light. Frequency-dependent phase and amplitude distortion are absent. As the read-out is of the nature of a servo device, dynamic range limitations are not encountered.

The prototype instrument is located in a region affected by the world rift system.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    R. C. BOSTROM: The World Rift System in the Pacific Northwest;Trend in Engineering 19, 27 (1967).Google Scholar
  2. [2]
    R. C. BOSTROM: The East Pacific Rise in the Northeast Pacific Ocean; inGeologic Problems of the Pacific Rim, (Tsukiji Shokan Co. Ltd., Tokyo), in press.Google Scholar
  3. [3]
    R.C. BOSTROM: Oceanward Spread of the Continental Crust in Southeast Alaska and Western British Columbia; read at 14th Annual Meeting, American Geophysical Union, Moscow, Idaho; abstr. inTrans. Amer. Geophys. Un., in press.Google Scholar
  4. [4]
    T. HAGIWARA and T. RIKITAKE: Japanese Program on Earthquake Prediction;Science, 157, 761 (1967).CrossRefGoogle Scholar
  5. [5]
    R. C. BOSTROM and V. VALI: A Seismometer Detecting Shear Strain;Trans. Amer. Geophys. Un., 48, 199 (1967).Google Scholar
  6. [6]
    V. VALI, R. S. KROGSTAD and W. VALI: Measurement of Earth Tides and Continental Drift Using Laser Interferometer,Proc. IEEE 52, 7 (1964).CrossRefGoogle Scholar
  7. [7]
    V. VALI, R. S. KROGSTAD and R. W. MOSS: Laser Interferometer for Earth Tide Strain Measurements;Rev. Scientific Instruments 36, 1352 (1965).CrossRefGoogle Scholar
  8. [8]
    H. van VEEN, J. SAVINO and L. ALSOP: An Optical Maser Strainmeter;J. Geophys. Res. 71, 5478 (1966).CrossRefGoogle Scholar

Copyright information

© Bureau Central de L’Association Internationale de Géodésie 1968

Authors and Affiliations

  • V. Vali
    • 1
    • 2
  • R. C. Bostrom
    • 1
    • 2
  1. 1.Boeing Scientific Research LaboratoriesSeattle
  2. 2.University of WashingtonSeattle

Personalised recommendations