pure and applied geophysics

, Volume 101, Issue 1, pp 74–89 | Cite as

Choice of a teleseismicP-wave travel-time model and the associated source corrections

  • S. K. Arora
  • C. A. Krishnan


Among various trial models ofP-wave travel times, there exists at least one model which best predicts the times of first arrivals from a certain region at a set of recording stations even if no attempt is made to correct the travel-time standards against known station errors and source bias. In teleseismic distance range (25°≦Δ≦100°) and surface-focus case, the possibility of statistically establishing which of the twoP models, viz. Jeffreys-Bullen and Herrin, is more appropriate for each of the four source regions, viz. Southern Nevada, Aleutian Islands, Eastern Kazakh and Novaya Zemlya, is discussed in this paper. Data corresponding to a set of underground explosions from these regions form the basis of such an analysis. The Herrin model is found to be better applied to Aleutian Islands region while the Jeffreys-Bullen model seems more appropriate for each of the remaining three regions.

As a result of the study of the travel-time models, numerical estimates of space and time corrections pertaining to the above mentioned regions, based on the most appropriate model and directly applicable to the computed source parameters, are obtained. On applying these corrections, the size of source location error ellipse and the source-time error reduce to very small representative values, viz. 4 km×6 km (area 75 km2) and ±0.2 sec respectively.


Location Error Source Parameter Recording Station Time Correction Distance Range 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    S.K.Arora andA.M.Manekar,Precise determination of epicenters and origin times of surface focus seismic events, Bull. Seism. Soc. Amer.59 (1969), 777.Google Scholar
  2. [2]
    S.K.Arora andC.A.Krishnan,Nuclear explosion data from Gauribidanur array, Government of India, Atomic Energy Commission Rep No. BARC/I-64 (1970).Google Scholar
  3. [3]
    C.Blamey andP.G.Gibbs,The epicenters and origin times of some large explosions, Geophys. J. R. Astr. Soc.16 (1968), 1.Google Scholar
  4. [4]
    B.A.Bolt andO.Nuttli,P-wave residuals as a function of azimuth, I.Observations, J. Geophys. Res.71 (1966), 5977.Google Scholar
  5. [5]
    D.S.Carder,Travel times from Central Pacific nuclear explosions, and inferred mantle structure, Bull. Seism. Soc. Amer.54 (1964), 2271.Google Scholar
  6. [6]
    D.S.Carder, D.W.Gordon andJ.N.Jordan,Analysis of surface-foci travel times Bull. Seism. Soc. Amer.56 (1966), 815.Google Scholar
  7. [7]
    J.R.Cleary,Azimuthal variation of the Longshot source term, Earth Planet. Sci. Lett.3, (1967), 29.Google Scholar
  8. [8]
    J.R.Cleary,P times to Australian stations from nuclear explosions, Bull. Seism. Soc. Amer.57, (1967), 773.Google Scholar
  9. [9]
    J.R.Cleary andA.L.Hales,An analysis of the travel times of P waves to North American Stations, in the distance range 32° to 100°, Bull. Seism. Soc. Amer.56 (1966), 467.Google Scholar
  10. [10]
    J.R.Cleary andK.J.Muirhead,Comparison of the 1968 P tables with times from nuclear explosions (I) Longshot and Greeley, Earth Planet. Sci. Lett.7 (1969), 119.Google Scholar
  11. [11]
    A.Douglas,Joint epicentre determination, Nature, Lond.215 (1967), 47.Google Scholar
  12. [12]
    E.A.Flinn,Confidence regions and error determinations for seismic event location, Rev. Geophys.3 (1965), 157.Google Scholar
  13. [13]
    E.Herrin,Introduction to ‘1968 Seismological Tables for P phases’ Bull. Seism. Soc. Amer.58 (1968), 1193.Google Scholar
  14. [14]
    E.Herrin andJ.Taggart,Regional variations in P n velocity and their effect on location of epicenters, Bull. Seism. Soc. Amer.52 (1962), 1037.Google Scholar
  15. [15]
    E.Herrin andJ.Taggart,Regional variations in P travel times, Bull. Seism. Soc. Amer.58 (1968), 1325.Google Scholar
  16. [16]
    E.Herrin andJ.Taggart,Source bias in epicenter determinations, Bull. Seism. Soc. Amer.58 (1968), 1791.Google Scholar
  17. [17]
    E.Herrin, W.Tucker, J.Taggart, D.W.Gordon andJ.L.Lobdell,Estimation of surface focus P travel times. Bull. Seism. Soc. Amer.58 (1968), 1273.Google Scholar
  18. [18]
    H.Jeffreys andK.E.Bullen,Seismological Tables, Brit. Assoc., Adv. Sci., Gray Milne Trust, London (1940), 48 pp.Google Scholar
  19. [19]
    H.Jeffreys,Revision of travel times Geophys. J. R. Astr. Soc.11, (1966), 5.Google Scholar
  20. [20]
    E.R.Lapwood andM.L.Gogna,Regional travel-times, Geophys. J. R. Astr. Soc.20 (1970), 383.Google Scholar
  21. [21]
    R.C.Lilwall andA.Douglas,The quest for a P travel time standard, Nature, Lond.222 (1969), 975.Google Scholar
  22. [22]
    R.C.Lilwall andA.Douglas,Estimation of P-wave travel times using the joint epicenter method, Geophys. J. R. Astr. Soc19 (1970), 165.Google Scholar
  23. [23]
    K.J.Muirhead andJ.R.Cleary,Comparison of the 1968 P tables with times from nuclear explosions (II) The Marshall Islands and Sahara series, Earth Planet. Sci. Lett.7 (1969), 132.Google Scholar
  24. [24]
    M.Otsuka,Azimuth and slowness anomalies of seismic waves measured on the central California seismographic array, Part I Observations, Bull. Seism. Soc. Amer.56 (1966), 223.Google Scholar
  25. [25]
    W.Tucker, E.Herrin andH.W.Freedman,Some statistical aspects of the estimation of seismic travel times, Bull. Seism. Soc. Amer.58 (1968), 1243.Google Scholar

Copyright information

© Birkhäuser Verlag 1972

Authors and Affiliations

  • S. K. Arora
    • 1
  • C. A. Krishnan
    • 1
  1. 1.Seismology Section, Nuclear Physics DivisionBhabha Atomic Research CenterBombay-85India

Personalised recommendations