Wide-Angle Shot Data (Sonobuoy) from the Eastern North American margin acquired during the R/V Marcus G. Langseth expedition MGL1407 (2014)

This sonobuoy data set was acquired during Marcus G. Langseth expedition MGL1407 conducted in 2014 (Chief Scientist: Dr. Deborah Hutchinson; Investigator(s): Dr. Deborah Hutchinson and Dr. Nathaniel Miller). These data files are of SEGY format and include Wide-Angle Seismic shot data that were processed after data collection to include MCS shotpoint information (shot number, time, lat/lon) which was added to the segy headers. The USGS conducted a 21-day geophysical survey along the Atlantic continental margin using R/V Marcus G. Langseth, expedition MGL1407 (USGS Field Activity Number 2014-011). The purpose was to collect multichannel seismic reflection data along the deep water portions of the margin (a) to determine sediment thickness and enable the U.S. to delineate the Atlantic extended continental shelf (ECS), and (b) to understand large submarine landslides and therefore assess their potential tsunami hazard for infrastructure and communities living on the Eastern Seaboard. The survey was conducted across the Atlantic continental margin, from near the junction of the slope and upper rise, in water depths greater than 1500 m, out to the abyssal floor in water depths greater than 5000 m. This field program had two primary objectives. 1) To collect the data necessary to establish the outer limits of the U.S. Continental Shelf, or Extended Continental Shelf (ECS), as defined by Article 76 of the Convention of the Law of the Sea. 2) To study the sudden mass transport of sediments down the continental margin as submarine landslides that pose potential tsunamigenic hazards to the Atlantic and Caribbean coastal communities. (http://cmgds.marine.usgs.gov/fan_info.php?fan=2014-011-FA)

本声纳浮标数据集系于2014年由马库斯·G·兰格塞特探险队（MGL1407）采集，该探险队由首席科学家德博拉·哈钦森博士领导，成员包括德博拉·哈钦森博士和纳撒尼尔·米勒博士。这些数据文件采用SEGY格式，并包含经数据处理后添加了MCS测点信息（测点编号、时间、经纬度）的宽角地震测井数据，该信息被添加至SEGY头部。美国地质调查局（USGS）利用“马库斯·G·兰格塞特”号（R/V Marcus G. Langseth）在MGL1407探险期间（USGS现场活动编号2014-011）沿大西洋大陆边缘进行了为期21天的地球物理调查。调查旨在收集沿大陆边缘深水部分的多通道地震反射数据，以确定沉积物厚度，并使美国能够划分大西洋外大陆架（ECS），同时（a）了解大型海底滑坡，并因此评估其对大西洋和加勒比海沿岸社区可能引发的 tsunami 危害；（b）调查沉积物沿大陆边缘的突发大规模迁移，即海底滑坡，这些滑坡可能对大西洋和加勒比海沿岸社区构成海啸灾害风险。调查范围覆盖大西洋大陆边缘，从斜坡与上部隆起交汇处附近，水深超过1500米，延伸至水深超过5000米的深海盆地。该野外项目有两个主要目标：1）收集建立美国大陆架外缘，或称扩展大陆架（ECS），所需的数据，该定义依据《联合国海洋法公约》第76条；2）研究沉积物沿大陆边缘的突发大规模迁移，即海底滑坡，这些滑坡可能对大西洋和加勒比海沿岸社区构成海啸灾害风险。详细信息请参考：（http://cmgds.marine.usgs.gov/fan_info.php?fan=2014-011-FA）