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871.
A GLORIA (Geological Long-Range Inclined Asdic) side-scan sonar survey, covering 23,000 km2, provides the first complete imagery of an active and contiguous, oceanic to continental back-arc system, namely, the Havre
Trough to Taupo Volcanic Zone (TVZ) New Zealand. Havre Trough tectonism and volcanism relates to a series of laterally discontinuous,
mutiple spreading rifts which terminate southward at the 3-km-deep Ngatoro Basin. A 45-km sinistral offset attributed toen echelon synthetic shearing separates the basin from the actively spreading TVZ. Sonographs reveal a youthful and complex volcanic
seascape with 20 newly discovered seamounts, whereas flanking regions are mantled with a largely featureless mud blanket. 相似文献
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Diseases of gadoid fish in cultivation: a review 总被引:1,自引:1,他引:1
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Dynamic processes observed at a gas hydrate outcropping on the continental slope of the Gulf of Mexico 总被引:1,自引:2,他引:1
Michael F. Vardaro Ian R. MacDonald Leslie C. Bender Norman L. Guinasso Jr 《Geo-Marine Letters》2006,26(1):6-15
A deep-sea time-lapse camera and several temperature probes were deployed on the Gulf of Mexico continental shelf at a biological
community associated with a gas hydrate outcropping to study topographic and hydrologic changes over time. The deployment
site, Bush Hill (GC-185), is located at 27°47.5′ N and 91°15.0′ W at depths of ∼540 m. The digital camera recorded one still
image every 6 h for July-October in 2001, every 2 h for the month of June 2002, and every 6 h for the month of July 2002.
Temperature probes were in place at the site for the entire experimental period. The data recovered provide a record of processes
that occur at gas hydrate mounds. Sediment resuspension over the mound causes significant variation in luminosity of the time-lapse
photographs. A marked diurnal pattern can be seen in the temperature and luminosity records. No major change in shape or size
of the gas hydrate outcrop at this site was observed during this study. Stable topography of the gas hydrate mound, combined
with high bacterial activity and sediment turnover, appears to focus biological activity in the mound area. Frequency and
recurrence of sediment resuspension indicate that short-term change in the depth and distribution of surface sediments is
a feature of the benthos at the site. Because the sediment interface is a critical environment for hydrocarbon oxidation and
chemosynthesis, short-term variability and heterogeneity may be important characteristics of these settings. 相似文献
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