Abstract
The arrival times of compressional (P) and shear (S) waves from approximately 580 microearthquakes recorded by a temporary array in the Pamir‐Hindu Kush region in central Asia are used to deduce one‐ and three‐dimensional velocity structures of this region. The results for one‐dimensional structures imply that the Moho is at 70±5 depth. Also, there is a velocity reversal near 160 km depth, which is inferred to be the beginning of the low velocity zone. This reversal continues to depths of approximately 230 km. Below 230 km, velocities are somewhat higher than those of normal mantle at similar depths (9.3 km/s versus 8.4 km/s for P waves). The outstanding feature of the results for three‐dimensional velocity structures is a broad (>40 km), centrally located region with 8 to 10% lower velocities than those in the surrounding regions. This low velocity region envelopes the seismic zone at depths between 70 and 150 km. The region may actually extend beyond these depths, but the results for shallower and deeper structure lack sufficient resolution to decide. Several tests, using both hypothetical and real data, were performed to estimate the reliability of the three‐dimensional solutions. The results of these tests suggest that the inferred velocities are reasonably accurate representations of the average velocities in the blocks, although one must be cautious of the effects of averaging in interpreting the solution. The low velocity region is inferred to be a manifestation of substantial quantities of subducted continental crust. Therefore, while subduction has occurred in the Pamir‐Hindu Kush, the results of the three‐dimensional inversions suggest that continental rather than only oceanic lithosphere has been subducted to depths of at least 150 km.Appendices are available with the entire article on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D.C., 20009. Document J81‐013; $1.00. Payment must accompany order.
References
39
Referenced
208
10.1029/JB081i023p04381
{'key': 'e_1_2_1_3_1', 'volume-title': 'Quantitative Seismology: Theory and Methods', 'author': 'Aki K.', 'year': '1980'}
/ Quantitative Seismology: Theory and Methods by Aki K. (1980)10.1785/BSSA0660020501
/ Bull. Seismol. Soc. Am. / Three‐dimensional seismic structure of the lithosphere under Montana, LASA by Aki K. (1976)10.1029/JZ066i007p02199
{'issue': '2', 'key': 'e_1_2_1_6_1', 'first-page': '371', 'article-title': "L'Evolution stratigraphique et structurale de L'Hindou Kouch central, en Afghanistan d'après la transversale du Salang", 'volume': '14', 'author': 'Boulin J.', 'year': '1972', 'journal-title': 'Rev. Geogr. Phys. Geol. Dyn.'}
/ Rev. Geogr. Phys. Geol. Dyn. / L'Evolution stratigraphique et structurale de L'Hindou Kouch central, en Afghanistan d'après la transversale du Salang by Boulin J. (1972)10.1016/0040-1951(80)90106-7
10.1029/JB085iB03p01365
{'key': 'e_1_2_1_9_1', 'first-page': '875', 'article-title': 'Three‐dimensional large scale mantle structure in central California', 'volume': '60', 'author': 'Cockerham R. S.', 'year': '1979', 'journal-title': 'EOS Trans. AGU'}
/ EOS Trans. AGU / Three‐dimensional large scale mantle structure in central California by Cockerham R. S. (1979)10.1029/JB081i017p03036
{'issue': '2', 'key': 'e_1_2_1_11_1', 'first-page': '345', 'article-title': "Esquisse Géologique de L'Afghanistan", 'volume': '14', 'author': 'De Lapparent A. F.', 'year': '1972', 'journal-title': 'Rev. Geogr. Phys. Geol. Dyn.'}
/ Rev. Geogr. Phys. Geol. Dyn. / Esquisse Géologique de L'Afghanistan by De Lapparent A. F. (1972)- Italian Expeditions to the Karakorum and Hindu Kush 3 Geology of Central Badakhshan (North‐East‐Afghanistan) and Surrounding CountriesA.Desio 628 E.J. Brill Leiden Netherlands 1975.
- Ellsworth W. L. Three‐dimensional structure of the crust and mantle beneath the island of Hawaii Ph.D. thesis 327 pp. Mass. Inst. of Technol. Cambridge 1977.
{'key': 'e_1_2_1_14_1', 'first-page': '406', 'volume-title': 'Subduction Zone Metamorphism', 'author': 'Ernst W. G.', 'year': '1975'}
/ Subduction Zone Metamorphism by Ernst W. G. (1975)10.1016/0022-247X(70)90017-X
{'key': 'e_1_2_1_16_1', 'first-page': '831', 'article-title': 'The Indian Ocean and the Himalayas: A geologic interpretation', 'volume': '59', 'author': 'Gansser A.', 'year': '1966', 'journal-title': 'Eclogae Geol. Helv.'}
/ Eclogae Geol. Helv. / The Indian Ocean and the Himalayas: A geologic interpretation by Gansser A. (1966){'key': 'e_1_2_1_17_1', 'first-page': '468', 'article-title': 'A tectonic model for the central part of the Scandinavian Caledonides', 'volume': '275', 'author': 'Gee D. G.', 'year': '1975', 'journal-title': 'Am. J. Sci.'}
/ Am. J. Sci. / A tectonic model for the central part of the Scandinavian Caledonides by Gee D. G. (1975)10.1016/0031-9201(80)90062-X
- Horie A. Three‐dimensional seismic velocity structure beneath the Kanto district by inversion of P wave arrival times Ph.D. thesis 59 pp. Univ. of Tokyo Tokyo 1980.
10.1016/0040-1951(64)90015-0
{'key': 'e_1_2_1_21_1', 'volume-title': 'Linear Differential Operators', 'author': 'Lanczos C.', 'year': '1961'}
/ Linear Differential Operators by Lanczos C. (1961)10.2475/ajs.271.3.193
-
Lee W. H. K. J. C.Lahr HYPO71 (revised): A computer program for determining hypocenter magnitude and first motion pattern of local earthquakes U.S. Geol. Surv. Open File Rep75‐311 1975.
(
10.3133/ofr75311
) 10.1090/qam/10666
{'key': 'e_1_2_1_25_1', 'first-page': '198', 'volume-title': 'Le anomalie della gravita lungo la catena del Karakorum‐Hindu Kush, publication', 'author': 'Marussi A.', 'year': '1963'}
/ Le anomalie della gravita lungo la catena del Karakorum‐Hindu Kush, publication by Marussi A. (1963)10.1029/JB082i002p00256
10.1029/JB076i008p01894
{'issue': '2', 'key': 'e_1_2_1_28_1', 'first-page': '341', 'article-title': "Géologie de la chaine d'Altimour (Afghanistan Oriental)", 'volume': '12', 'author': 'Mennessier G.', 'year': '1972', 'journal-title': 'Rev. Geogr. Phys. Geol. Dyn.'}
/ Rev. Geogr. Phys. Geol. Dyn. / Géologie de la chaine d'Altimour (Afghanistan Oriental) by Mennessier G. (1972)10.1130/0091-7613(1979)7<58:SOCLSC>2.0.CO;2
10.1038/239202a0
10.1029/JB085iB09p04801
- Peive A. V. V. S.Burtman S. V.Ruzhentsev A. I.Suvorov Tectonics of the Pamir‐Himalayan sector of Asia22nd Session of the International Geological CongressNew Delhi India 1964.
10.1111/j.1365-246X.1980.tb02616.x
10.1029/JZ071i022p05297
10.1016/0012-821X(79)90023-2
- Roecker S. W. Seismicity and tectonics of the Pamir‐Hindu Kush region of central Asia Ph.D. thesis 298 pp. Mass. Inst. of Technol. Cambridge 1981.
10.1111/j.1365-246X.1980.tb02617.x
10.1111/j.1365-246X.1980.tb02612.x
{'key': 'e_1_2_1_39_1', 'first-page': '1', 'article-title': 'Spectral analysis of the coda waves from local earthquakes', 'volume': '53', 'author': 'Tsujiura M.', 'year': '1978', 'journal-title': 'Bull. Earthquake Res. Inst., Tokyo Univ.'}
/ Bull. Earthquake Res. Inst., Tokyo Univ. / Spectral analysis of the coda waves from local earthquakes by Tsujiura M. (1978)- Zandt G. Study of three‐dimensional heterogeneity beneath seismic arrays in central California and Yellowstone Wyoming Ph.D. thesis 490 pp. Mass. Inst. of Technol. Cambridge 1978.
Dates
Type | When |
---|---|
Created | 17 years, 7 months ago (Feb. 6, 2008, 9:25 a.m.) |
Deposited | 1 year, 11 months ago (Sept. 22, 2023, 7:20 a.m.) |
Indexed | 1 week, 1 day ago (Aug. 29, 2025, 6:41 a.m.) |
Issued | 43 years, 6 months ago (Feb. 10, 1982) |
Published | 43 years, 6 months ago (Feb. 10, 1982) |
Published Online | 12 years, 11 months ago (Sept. 20, 2012) |
Published Print | 43 years, 6 months ago (Feb. 10, 1982) |
@article{Roecker_1982, title={Velocity structure of the Pamir‐Hindu Kush Region: Possible evidence of subducted crust}, volume={87}, ISSN={0148-0227}, url={http://dx.doi.org/10.1029/jb087ib02p00945}, DOI={10.1029/jb087ib02p00945}, number={B2}, journal={Journal of Geophysical Research: Solid Earth}, publisher={American Geophysical Union (AGU)}, author={Roecker, S. W.}, year={1982}, month=feb, pages={945–959} }