| Abstract: | High-resolution seismic reflection data, recorded offshore from Prudhoe Bay, Alaska, were processed digitally to determine the reflectivity structure of the uppermost layers of the seafloor. A prominent reflector, found at 27 m below the mud line (water depths 7-9 m), has a negative reflection coefficient greater than 0.5. The large acoustic impedance contrast, coupled with a report of gas encountered at a corresponding depth in a nearby drillhole, shows that the reflector is the upper boundary of a zone containing gas. The gas exists in sandy gravel capped by stiff, silty clay. Analysis of unprocessed conventional high-resolution records from the region indicates that the gas-bearing layer may extend over an area of at least 50 km2 at a depth of 20-35 m below the mud line. Similar-appearing reflectors (Reimnitz, 1972), previously unexplained, occur in patches over wide regions of the shelf where offshore oil development is beginning at a rapid pace. This suggests the exercise of caution with respect to possible hazards from shallow gas pockets. |
| Genre: | Article |
| ProdID: | 70012019 |
| Citation Author: | Boucher, G.; Reimnitz, E.; Kempema, E. |
| Citation Contributing Office: | Energy Resources Program |
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| Citation End Page: | 71 |
| Citation Issue: | 1 |
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| Citation Language: | English |
| Citation Larger Work Title: | Cold Regions Science and Technology |
| Citation LatN: | 71.4 |
| Citation LatS: | 51.2 |
| Citation LonE: | -130.0 |
| Citation LonW: | 172.5 |
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| Citation Online Only Flag: | |
| Citation Phsyical Description: | 9 p. |
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| Citation Publisher: | Elsevier |
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| Citation Search Results Text: | Seismic evidence for an extensive gas-bearing layer at shallow depth, offshore from Prudhoe Bay, Alaska; 1981; Article; Journal; Cold Regions Science and Technology; Boucher, G.; Reimnitz, E.; Kempema, E. |
| Citation Start Page: | 63 |
| Citation Volume: | 4 |
| Citation Year: | 1981 |
| Type: | citation/reference |
| Text: | Seismic evidence for an extensive gas-bearing layer at shallow depth, offshore from Prudhoe Bay, Alaska; 1981; Article; Journal; Cold Regions Science and Technology; Boucher, G.; Reimnitz, E.; Kempema, E. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.1016/0165-232X(81)90031-8 |
| Date Other: | Thu, 1 Jan 1981 00:00 -0600 |
| Publisher: | Elsevier |
| Superseded by: |
http://pubs.er.usgs.gov/publication/ofr80809
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