Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Quest for a P Travel Time Standard


ATTEMPTS have been made recently1–3 to revise the Jeffreys–Bullen (J.–B.) travel time tables4 and Herrin et al.5,6 have published a set of tables which are intended as a new standard. But these new tables fail to predict the P travel times for some explosions with known epicentres and origin times. Most notably, the P waves generated by the Longshot (Aleutian Island) explosion arrive earlier than predicted at stations to the north of the Aleutian arc and later than predicted at stations to the south. This bias in the P wave travel time results in a mislocation by about 25 km when the epicentre of Longshot is computed by standard methods. The cause of this travel time bias is usually attributed to the effects of structure beneath the Longshot firing site—and the term source bias has been proposed by Herrin and Taggart7 to describe the phenomenon.

This is a preview of subscription content, access via your institution

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. Cleary, J., and Hales, A. L., Bull. Seis. Soc. Amer., 56, 467 (1966).

    Google Scholar 

  2. Carder, D. S., Gordon, D. W., and Jordan, J. N., Bull. Seis. Soc. Amer., 56, 815 (1966).

    Google Scholar 

  3. Gogna, M. L., Geophys. J. Roy. Astron. Soc., 13, 503 (1967).

    ADS  Article  Google Scholar 

  4. Jeffreys, H., and Bullen, K. E., Seismological Tables (Brit. Assoc. Gray–Milne Trust, 1940).

    Google Scholar 

  5. Herrin, E., Bull. Seis. Soc. Amer., 58, 1193 (1968).

    Google Scholar 

  6. Herrin, E., and Taggart, J. N., Bull. Seis. Soc. Amer., 58, 1325 (1968).

    Google Scholar 

  7. Herrin, E., and Taggart, J. N., Bull. Seis. Soc. Amer., 58 (in the press).

  8. Douglas, A., and Lilwall, R. C., Nature, 220, 469 (1968).

    ADS  Article  Google Scholar 

  9. Douglas, A., Nature, 215, 47 (1967).

    ADS  Article  Google Scholar 

  10. Herrin, E., Tucker, W., Taggart, J. N., Gordon, D. W., and Lobdell, J. L., Bull. Seis. Soc. Amer., 58, 1273 (1968).

    Google Scholar 

  11. USCGS Earthquake Data Rep., P.D.E. 67/47 (1967).

  12. Koyanagi, R. Y., Krivoy, H. L., and Okamura, A. T., Bull. Seis. Soc. Amer., 56, 1317 (1966).

    Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

LILWALL, R., DOUGLAS, A. Quest for a P Travel Time Standard. Nature 222, 975–977 (1969).

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing