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Research about Shelikof Strait

Source-linked reports with geographic coverage including Shelikof Strait.

5 recordsLinked to original sources
USGS1999

Multi-year persistence of oil mousse on high energy beaches distant from the Exxon Valdez spill origin

For at least 5 yr after the Exxon Valdez spill, relatively unweathered oil mousse has persisted on the exposed rocky shores of Shelikof Strait 500 km from Prince William Sound, Alaska. Previously it was thought that oil would be rapidly removed from such geomorphic settings by wave action. Oil mousse persists at sites in Katmai National Park and Preserve (NP&P) where it was stranded high in the intertidal zone under a lag of large boulders. These boulders armor the beach, preventing waves from disturbing the substrate and its included oil. Weathering of this stranded mousse has been slight – mousse sampled in 1989, 1992 and 1994 show negligible changes in polynuclear aromatic hydrocarbons compared to 11-day old Exxon Valdez crude. The preservation of this oil is due to its transport as mousse boli whose interiors largely escape weathering, followed by its sheltering in the interstices of boulder-armored beaches. The transport of mousse may allow for the long distance dispersal of less weathered, and hence still toxic oil. Our findings suggest that the low ecological sensitivity ratings previously applied to exposed, rocky shorelines need to be modified. The biological threat posed by oil stranded on the Katmai NP&P coast probably is slight because of its small amount and sequestered state. However, it still possesses the ability to be chemically toxic and could be released through disturbance of the armoring boulders by unusually high wave events.

Alaska↗
USGS1985

Quaternary sedimentation in Shelikof Strait, Alaska

Shelikof Strait, a nearly parallel-sided marine channel between the Kodiak Island group and the Alaska Peninsula, has experienced a succession of distinct sedimentary environments during Quaternary time. Pleistocene glaciers carved a deep basin into bedrock in the southwest part of the strait and a shallower platform surface with incised channels in the northeast. The basin and channels were filled with glacial and glacialmarine sediment before and during the time that ice retreated and oceanic conditions returned. Restricted marine conditions prevailed in early Holocene time and sediment prograded transversely into the strait from the adjacent landmasses, with some localized dispersal to the deep, central strait. Onset of modern open-marine conditions commenced when regional currents breached the sill across Kennedy and Stevenson Entrances to combine with sediment-laden outflow from Cook Inlet and deposit a blanket of well-stratified sediment throughout the strait.

Alaska↗
USGS1981

Description of seafloor sediment and preliminary geo-environmental report, Shelikof Strait, Alaska

Shelikof Strait, situated between the Kodiak Island group and the Alaska Peninsula (Fig. 1), is included in OCS oil and gas lease area 60. Environmental geologic studies are being conducted by the U.S. Geological Survey prior to the scheduled September 1981 sale date. Seismic-reflection records, collected with 40- to 95-cm3 airgun, 800-joule minisparker, 800-joule boomer, and 3.5-and 12-kilohertz systems and covering over 6,400 km of trackline have been examined to identify geologic conditions at or below the seafloor that might affect petroleum operations. Of the total trackline distance, 865 km were collected in June 1980 aboard the Geological Survey's ship R/V S.P. LEE. The remainder were collected by Nekton Inc. in 1979, under contract to the USGS (Fig. 2). Sediment samples were collected at 42 stations on the June 1980 cruise for geological and geotechnical analysis (Fig. 2). The purpose of this report is to present physical and chemical measurements that have been made on sediment samples and to give a preliminary geo-environmental assessment of Shelikof Strait, based on presently completed analyses of the geophysical records and sediment samples.

Alaska↗