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CDP seismic reflection data for lines 18 through 38
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from Atlantic coastal areas were collected as part of a program
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by the U.S. Geological Survey (USGS) to survey the geological
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framework of the United States coastal areas.
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During 1978, USGS contracted with Geophysical Services, Inc.
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(GSI), for GSI to collect 4,813 km of 48-channel seismic
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reflection profiles along the continental margin between North
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Carolina and Maine. Fifteen lines were acquired perpendicular to
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the margin (lines 18 through 32) and six lines were acquired
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parallel to the margin (lines 33 through 38). The data were
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collected on the vessels CARINO and CECIL GREEN between May
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and November 1978. Tuned airgun arrays totaling 2,000 and 1,400
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cu. in. of air were used by the respective vessels. A 3,600-m-
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long hydrophone streamer was used by both ships.
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The profiles were stacked by GSI and displayed in conventional
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time-variant scaled format to 12 sec of recording time with
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vertical scales of 2.5 in/sec and horizontal scales of 1.2 km/in.
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Additional processing was applied to Line 25 across the Baltimore
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Canyon Trough and Line 32 across Carolina Trough. Data collected
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along line 25 over the Outer Shelf, Slope, and Upper Rise were
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restacked with 1 1/2-km spaced velocity analyses, signature
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deconvolution, deep-water multiple deconvolution, velocity
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filtering (on shelf only), and time migration. The restacked
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part and remaining parts of Line 25 were converted to depth
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sections having a vertical scale of 1.2 km/in (vertical
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exaggeration: 2/1). Data collected along two parts of line 32
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were also restacked with signature and deep-water multiple
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deconvolution. Line 32 was also converted to a depth section
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except for the first 80 km near shore.
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