Locations of All Shotpoints, USGS Cruise M1-98-GM (GOM98SHTALLG.SHP)

All shotpoint locations from multichannel seismics survey, USGS cruise M1-98-GM. During June 1998 and April 1999, the U.S. Geological Survey (USGS) conducted two research cruises in the northern Gulf of Mexico to acquire high-resolution seismic reflection data across the upper and middle continental slope as part of an investigation of the seismic character, distribution, and potential effects of naturally-occurring marine gas hydrates and related free gas within the gas hydrate stability zone. Over 1600 km of two-dimensional multichannel seismic reflection profiles were acquired during these two cruises. The specific objectives of this investigation are (a) to produce high-resolution images of the gas hydrate stability zone; (b) to study the distribution and character of potential seafloor failures and their relationship to known and inferred gas hydrate deposits; (c) to look at systematic variations in subsurface structure in gas hydrate and non-hydrate areas; and (d) to estimate, if possible, the amounts of hydrates present within the gas hydrate stability zone. The multichannel profiles provide high-quality images with approximately 5 meters of vertical resolution and up to 2 km of penetration. This report gives an overview of the acquisition and data processing of the multichannel seismic reflection profiles and provides references and links to reports with more detailed information. Geologic interpretations of these seismic profiles regarding gas hydrate occurrence and distribution within the study areas of this investigation are given in Hart and others (2002).美国地质调查局（U.S. Geological Survey, USGS）M1-98-GM航次多道地震勘探（multichannel seismic survey）的全部炮点位置。 1998年6月至1999年4月期间，美国地质调查局（USGS）在墨西哥湾北部开展两次科考航次，在大陆坡上、中部区域采集高分辨率地震反射数据，作为针对天然气水合物稳定带（gas hydrate stability zone）内天然海底天然气水合物及其伴生游离气的地震特征、分布规律与潜在影响开展系统调查的组成部分。 两次航次共采集超过1600千米的二维多道地震反射测线。 本次调查的具体目标包括：(a) 获取天然气水合物稳定带的高分辨率成像结果；(b) 研究潜在海底滑坡的分布与特征，及其与已探明和推断的天然气水合物矿床的关联；(c) 对比分析天然气水合物分布区与非水合物分布区的地下构造系统变化；(d) 尽可能估算天然气水合物稳定带内赋存的水合物资源总量。 该多道地震测线可提供高质量成像成果，垂直分辨率约为5米，最大穿透深度可达2千米。 本报告对本次多道地震反射测线的采集与数据处理工作进行了全面概述，并提供了包含更详细研究内容的相关报告的参考文献与链接。 关于本次研究区内地震测线的天然气水合物赋存状态与分布规律的地质解译结果，详见Hart等人（2002）的研究成果。