Abstract High-resolution seismic surveys were carried out in the inner shelf of the East China Sea to investigate the distribution of shallow gas in Holocene sediments. Shallow gas is distributed extensively in the Holocene strata of the shelf which is dominated by the Yangtze River. Organic-rich, fine-grain sediments deposited throughout the Holocene are essential for gas generation and accumulation. The thickness of the Holocene sediment is the main controlling factor determining the distribution of shallow gas. Gas seepages were found mostly at a water depth up to 20 m, where sediment erosion mainly occurs. Coincidence between shallow gas seepage and high methane concentration in the water column suggests that gas emission from these sediments is a potentially significant source of greenhouse gas. The interaction between shallow gas migration and coastal erosion would therefore potentially lead to increased greenhouse gas emission and accelerated sediment erosion. Such results can be applied to other costal locations around the world.

中文翻译：

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东海内陆架全新世泥楔中的浅层气

摘要 在东海内陆架开展了高分辨率地震勘探，研究了浅层气体在全新世沉积物中的分布。浅层气广泛分布于以长江为主的陆架全新世地层。整个全新世沉积的富含有机物的细粒沉积物对于天然气的生成和聚集至关重要。全新世沉积物的厚度是决定浅层气分布的主要控制因素。瓦斯渗漏主要发生在20 m以下的水深，以泥沙侵蚀为主。浅层气体渗漏与水体中高甲烷浓度之间的巧合表明，这些沉积物的气体排放是温室气体的潜在重要来源。因此，浅层气体迁移和海岸侵蚀之间的相互作用可能会导致温室气体排放增加和沉积物侵蚀加速。这样的结果可以应用于世界其他沿海地区。