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Detailed Reference Information |
Stephen, R.A. (1988). Lateral heterogeneity in the upper oceanic crust at deep sea drilling project site 504. Journal of Geophysical Research 93: doi: 10.1029/88JB01426. issn: 0148-0227. |
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The lateral variability of the upper oceanic crust can be studied by mapping the amplitude (or power) content of arrivals from a dense array of identical sources to a single receiver. In this paper we present the results from a borehole seismic experiment at Deep Sea Drilling Project site 04 in the eastern equatorial Pacific. Seismic amplitude anomalies of 20 dB and more are present with a horizontal correlation length of 1--3 km. Finite difference synthetic seismogram techniques are used to predict seismic wave propagation through realistic bathymetry, basement relief, and lateral variations within basement. A three-dimensional model of the velocity structure around the borehole can be constructed. The resultant model has horizontal gradients greater than 2.0 s-1 in the upper crust. These gradients are comparable to the vertical gradients normally associated with oceanic crust. Assuming that velocity anomalies in the upper crust reflect changes in porosity, the resultant structure provides constraints on the hydrothermal circulation at the site. In addition, the finite difference modeling indicates that polarity reversals can be generated by lateral velocity variations near the source and receiver. ¿ American Geophysical Union 1988 |
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Abstract |
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Keywords
Marine Geology and Geophysics, Marine seismics, Exploration Geophysics, Oceanic structures, Exploration Geophysics, Seismic methods, Seismology, Body wave propagation |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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