Abstract
Although there have been extensive seismic refraction measurements over areas of continental crust, the causes of variation in crustal thickness, and of variation in mean crustal seismic velocity, are poorly understood. If there is regional (3° × 3°) isostatic equilibrium of the crust, such as suggested by many studies of regional gravity, then crustal thickness variation should be caused largely by variation in surface altitude and crustal density. Seismic refraction results from Australia are used here to confirm that these crustal isostatic effects are a major (40%) cause of variation of crustal thickness even in a continent of little surface relief. However, there is an equally important regional variation in crustal thickness unrelated to crustal isostasy—this is thought to be due to density variation in the lower lithosphere1.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Cochran, J. R. & Talwani, M. Geophys. J. R. astr. Soc. 50, 495–522 (1977).
Woollard, G. P. Phys. Earth planet. Inter. 3, 484–498 (1970).
Talwani, M., Sutton, G. H. & Worzel, J. O. J. geophys. Res. 64, 1545–1555 (1959).
Drummond, B. J., Smith, R. E. & Horwitz, R. C. Geol. Soc. Aust. Spec. Publ. 7, 33–41 (1981).
Wellman, P. BMR J. Aust. J. Geol. Geophys. 1, 297–302 (1976); 3, 153–162 (1978); 4, 373–382 (1979).
Manghnani, M. H., Ramananantoandro, R. & Clark, S. P. J. geophys. Res. 79, 4527–5446 (1974).
Drummond, B. J. & Shelley, H. M. BMR J. Aust. Geol. Geophys. 6, 137–143 (1981).
Cleary, J. Bull. seis. Soc. Am. 57, 773–781 (1967).
Everingham, I. B. Bur. Min. Resourc. Aust. Rec. 1969/22 (1969).
Cleary, J. R., Simpson, D. W. & Muirhead, K. J. Nature 236, 111–112 (1972).
Cull, J. P. BMR J. Aust. Geol. Geophys. 7, 11–21 (1982).
Jordan, T. H. Nature 274, 554–548 (1978).
Dooley, J. C. BMR J. Aust. Geol. Geophys. 2, 1–5 (1977).
Cleary, J. R. Tectonophysics 20, 241–248 (1973).
Finlayson, D. M. J. geol. Soc. Aust. 15, 35–50 (1968).
Mathur, S. P. Tectonophysics 24, 151–182 (1974).
Collins, C. D. N. BMR J. Aust. Geol. Geophys. 3, 203–209 (1978).
Shackleford, P. R. J. & Sutton, D. J. J. geol. Soc. Aust. 28, 491–500 (1981).
Finlayson, D. M., Collins, C. D. N. & Denham, D. Phys. Earth planet. Inter. 21, 321–342 (1980).
Finlayson, D. M., Prodehl, C. & Collins, C. D. N. BMR J. Aust. Geol. Geophys. 4, 243–252 (1979).
Finlayson, D. M. & McCracken, H. M. J. geol. Soc. Aust. 28, 177–190 (1981).
Drummond, B. J. BMR J. Aust. Geol. Geophys. 4, 171–180 (1979).
Drummond, B. J. BMR J. Geol. Geophys. 6, 123–135 (1981).
Finlayson, D. M. J. geophys. Res. (in the press).
Collins, C. D. N. BMR J. Aust. Geol. Geophys. (in the press).
Jacobson, R. S., Shor, G. G., Kieckhefer, R. M. & Purdy, G. M. Am. Ass. petrol. Geol. Mem. 29, 209–222 (1979).
Rynn, J. M. W. & Reid, I. D. J. geol. Soc. Aust. (in the press).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wellman, P. Australian seismic refraction results, isostasy and altitude anomalies. Nature 298, 838–841 (1982). https://doi.org/10.1038/298838a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/298838a0
Comments
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.
