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地震通常被作为造成长距离顺坡搬运大体积沉积物并在海洋和湖泊中沉降下来的浊流—致密沉积—水柱的一种可能的引发机制(Heezen and Ewing,1952;Inouchi.et al,1996;Grantz,et al,1996;Gorsline,1996;Thomson and Weaver,1994;Hughen,et al,1996)。Heezen 和 Ewing(1952)首次提出了这样的设想,北大西洋海底电缆的折断应归因于1929年大浅滩地震产生的海底浊流。为此一些工作者用沉积物的浊度记录重建许多地方的地震历史(Inouchi,et al,1996;Adams,1990;Doig,1990)。本文给出了一次地震导致浊流的直接观测结果。在卡里亚科海盆内的光散射和沉积物流量的测定表明,委内瑞拉北部海岸,1997年7月9日发生的地震造成大约超过10~(15)kg 的沉积物下滑至海盆深部。在这样的地震活动区,沉积物的这种运移机制可能是海盆内沉积物长期累积的重要原因。此外,这种过程可能导致最初在浅海中沉积的大量碳质被封存在深海沉积物中。
Earthquakes are often used as a possible triggering mechanism for turbidity-dense sedimentation-water columns that cause large deposits to sediment and settle in oceans and lakes over long distances (Heezen and Ewing, 1952; Inouchi et al., 1996 ; Grantz, et al, 1996; Gorsline, 1996; Thomson and Weaver, 1994; Hughen, et al, 1996). For the first time, Heezen and Ewing (1952) put forward the idea that the break of the North Atlantic submarine cable should be attributed to the turbidity of the seabed produced by the 1929 Great Shoal Earthquake. For this reason, some workers use sediment turbidity records to reconstruct the seismic history in many places (Inouchi, et al., 1996; Adams, 1990; Doig, 1990). This paper gives a direct observation of the turbidity caused by an earthquake. Light scattering and sediment flux measurements in the Cariacoya basin indicate that an earthquake of 9 July 1997 in the northern coast of Venezuela caused deposits of more than about 10 to 15 kg to slide down into the deep of the basin. In such seismic zones, this mechanism of sediment transport may be an important reason for the long-term accumulation of sediments in the basin. In addition, this process may result in the large amount of carbon originally deposited in the shallow sea being trapped in deep sea sediments.