Green Canyon Lease Block 600 is a well-documented cold seep site characterized by near-perennial oil and gas slicks large enough to reach the sea surface and to be detected on satellite imagery. This site has been selected by the Ecosystem Impact of Oil and Gas Inputs to the Gulf consortium to study the impacts of natural hydrocarbon seepage versus anthropogenic inputs of hydrocarbons into the Gulf of Mexico ecosystem following the Deepwater Horizon oil spill disaster that occurred in 2010. Here we present the first high-resolution characterization of the site. We investigated the seafloor and shallow subsurface combining autonomous underwater vehicle-borne seismo-acoustics with photo data. Our records show vigorous hydrocarbon flux occurring over a wide area of the complex seafloor morphology. Several mounds, which are the most prominent features of the site, are aligned along a ridge structure and are actively venting hydrocarbons. Detailed bathymetry of the mound’s surface highlights the presence of numerous pockmarks, cones, and micro-mounds of variable sizes and shapes. High reflectivity seafloor backscatter characterizes the entire ridge surface; ground-truthing photo surveys confirm the presence of authigenic carbonate hardgrounds, gas hydrates, and chemosynthetic communities. The shallow stratigraphy indicates that the ridge represents the seafloor expression of normal faults, probably rooted to a deep salt body. Salt tectonics generated a complex network of normal faults, many of which displace the upper part of the Holocene sediments up to the seafloor, forming long linear scars. Acoustic anomalies, interpreted as active migration pathways, underlie mounds and venting structures, suggesting a link between the deep hydrocarbon reservoir and seafloor expulsion features.

中文翻译：

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墨西哥湾深水多年生烃类渗漏绿色峡谷600的高分辨率地震声特征

Green Canyon Lease Block 600是一个有据可查的冷渗漏地点，其特征是近多年生的石油和天然气浮油大到足以到达海面并可以在卫星图像上检测到。在2010年发生的“深水地平线”漏油灾难之后，该地点已被“墨西哥湾财团的油气输入对生态系统的影响”选中，以研究天然碳氢化合物渗透与人为因素对墨西哥湾生态系统的碳氢化合物输入的影响。我们展示了该站点的第一个高分辨率特征。我们研究了海底和浅层地下，结合了自主水下车载声波声学与照片数据。我们的记录显示，在复杂的海底形态的大范围内都出现了剧烈的烃通量。几墩 这些是该站点最突出的特征，沿着山脊结构排列并正在积极排放碳氢化合物。土墩表面的详细测深图突出显示了各种大小和形状各异的麻子，圆锥体和微型土墩的存在。高反射率的海底反向散射是整个山脊表面的特征。地面真相照片调查证实了自生的碳酸盐硬土，天然气水合物和化学合成群落的存在。浅层地层表明该脊代表正常断层的海底表达，可能扎根于深部盐体。盐构造构造了一个由正常断层组成的复杂网络，其中许多断层将全新世沉积物的上部移至海底，形成了长长的线性疤痕。声学异常，被解释为活跃的迁移途径，