Crustal Structure of the Northwest Deccan Volcanic Province, India,and the Adjoining Continental Shelf from Observed Surface-Wave Dispersion

2011 ◽  
Vol 101 (4) ◽  
pp. 1488-1495 ◽  
Author(s):  
S. Prajapati ◽  
G. Suresh ◽  
S. N. Bhattacharya
Keyword(s):  
Surface Wave ◽  
Continental Shelf ◽  
Crustal Structure ◽  
Wave Dispersion ◽  
Deccan Volcanic Province ◽  
Surface Wave Dispersion ◽  
Volcanic Province

Short-period surface-wave dispersion and shallow crustal structure of central and eastern Tennessee

1992 ◽  
Vol 82 (2) ◽  
pp. 962-979
Author(s):  
Paul C. Yao ◽  
James Dorman
Keyword(s):  
Surface Wave ◽  
Half Space ◽  
Crustal Structure ◽  
Group Velocity Dispersion ◽  
Wave Dispersion ◽  
Surface Wave Dispersion ◽  
Zero Crossing ◽  
Clastic Rocks ◽  
Dispersion Data ◽  
Short Period

Abstract Group velocity dispersion of explosion-generated seismic surface waves with periods ranging from 0.2 to 1.5 sec is used to investigate shallow crustal structure of eastern and central Tennessee. Several modes of both Rayleigh and Love waves can be identified and separated on the seismograms of seven SARSN regional network stations by zero-phase digital filtering. Dispersion data for sinusoidal wave motion were based on digitized zero-crossing times. By forward modeling, we find that a wave guide of at least two layers over a half-space can adequately represent our particular multi-mode, narrow-band observations. In a layered section about 3 km thick, lower velocities characterize outcropping clastic rocks of the Cumberland plateau, and higher velocities correspond to shallow carbonate rocks of the Nashville Dome. Half-space shear velocities of about 3.9 km/sec appear to represent lower Paleozoic carbonate lithology deeper than 2 to 4 km on most of the observed paths. Our best data, interpreted jointly with earlier data of Oliver and Ewing (1958) and of Chen et al. (1989), have a composite period range of 0.2 to 40 sec, but they represent different Appalachian paths. Group velocities over this broad spectrum are satisfied by a complex model with two low-velocity layers. The uniqueness of this model cannot be demonstrated, but it represents important hypotheses concerning regional geologic features that can be tested more rigorously by improved surface-wave dispersion data.

SURFACE‐WAVE DISPERSION APPLIED TO THE DETECTION OF SEDIMENTARY BASINS

Geophysics ◽  
1975 ◽  
Vol 40 (1) ◽  
pp. 40-55 ◽  
Author(s):  
Robert H. Tatham
Keyword(s):  
Surface Wave ◽  
Crustal Structure ◽  
Gulf Coast ◽  
Sedimentary Basins ◽  
Wave Dispersion ◽  
Petroleum Exploration ◽  
Underground Nuclear Explosion ◽  
Surface Wave Dispersion ◽  
Mississippi Embayment ◽  
Model Calculations

Seismic surface‐wave velocities are greatly affected by crustal structure. Because there is a strong contrast in the physical properties of clastic sediments and underlying basement materials, surface‐wave dispersion provides a fast, convenient, and inexpensive means of detecting sedimentary basins and estimating their thickness. Model calculations and published reports of explosion studies indicate that sedimentary thicknesses as shallow as 500 m (∼1650 ft) should be detectable by analysis of routinely recorded earthquake seismograms. This study demonstrates the use of seismic surface‐wave dispersion to detect sedimentary basins and to estimate their thickness. The technique is used first for the Mississippi embayment region of the U.S. Gulf Coast, where the crustal structure is known and the results can be verified, and then applied to offshore Greenland, where the crustal structure is unmapped but a sedimentary basin is suspected. The data used are available seismograms of natural earthquakes and, for the Gulf Coast area, an underground nuclear explosion. Because this technique requires only existing, readily available data and may be applied to many regions of the world, it offers an attractive reconnaissance tool in petroleum exploration. In the present study, surface‐wave dispersion and the effects of shallow crustal structure are reviewed in light of this application, and the advantages and limitations of the technique are explored.

scholarly journals CRUSTAL STRUCTURE AND SURFACE-WAVE DISPERSION

1955 ◽  
Vol 66 (7) ◽  
pp. 913 ◽  
Author(s):  
JACK E. OLIVER ◽  
MAURICE EWING ◽  
FRANK PRESS
Keyword(s):  
Surface Wave ◽  
Crustal Structure ◽  
Wave Dispersion ◽  
Surface Wave Dispersion

Crustal structure of the Iceland region from dispersion of surface waves

1962 ◽  
Vol 52 (2) ◽  
pp. 359-388
Author(s):  
Eysteinn Tryggvason
Keyword(s):  
Surface Layer ◽  
Surface Wave ◽  
Surface Waves ◽  
Wave Velocity ◽  
Crustal Structure ◽  
Wave Dispersion ◽  
P Wave ◽  
S Wave ◽  
Surface Wave Dispersion ◽  
Mid Atlantic Ridge

ABSTRACT A number of Icelandic records of earthquakes originating in the Mid-Atlantic Seismic Belt between 52° and 70° N. lat. have been investigated. The surface waves on these records are chiefly in the period interval 3–10 sec, and are first mode Love-waves and Rayleigh-waves. The surface wave dispersion can be explained by a three-layered crustal structure as follows. A surface layer of S-wave velocity about 2.7 km/sec covering the whole region studied, a second layer of S-wave velocity about 3.6 km/sec covering Iceland and extending several hundred kilometers off the coasts and a third layer of S-wave velocity about 4.3 km/sec and P-wave velocity about 7.4 km/sec underlying the whole region. The thickness of the surface layer appears to be about 4 km on the Mid-Atlantic Ridge south of Iceland and in western Iceland, 3 km in central Iceland and 7 km northwest of Iceland. The second layer is apparently of similar thickness than the surface layer, while the third layer is thick; and the surface wave dispersion does not indicate any layer of higher wave velocity. This 7.4-layer is supposed to belong to the mantle, although its wave velocity is significantly lower than usually found in the upper mantle

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