14BIM05_IFB_tracklines: Shapefile of the Interferometric Swath Bathymetry Tracklines Surveyed in 2014 near Breton Island, Louisiana

As part of the Barrier Island Monitoring Project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off Breton and Gosier Islands, Louisiana, in July and August of 2014. To assist the United States Fish and Wildlife Service (USFWS) with restoration planning efforts, the USGS was tasked with answering fundamental questions about the physical environment of the southern Chandeleur Islands, including the geology, morphology, and oceanography. Baseline data needed to answer these questions was either insufficient or missing in the area. The USGS conducted a comprehensive geologic investigation in the summer of 2014 by collecting geophysical and sedimentological data.
Breton Island, located at the southern end of the Chandeleur Island chain, Louisiana, was recognized as a natural and globally important nesting sanctuary for several bird species and was established as the Breton National Wildlife Refuge (NWR) in 1904. The aerial extent of Breton Island has diminished 90% since 1920. Land loss is attributed to ongoing relative sea-level rise, diminished sediment supply, and storm impacts. The bird population on Breton Island has also declined over the years, most notably after Hurricane George in 1998 and Hurricane Katrina in 2015, which completely submerged the island. Despite the decreasing habitable acreage, migratory seabirds continue to return and utilize Breton Island. To prevent the island from being completely submerged in the future and to protect, stabilize, and provide more nesting and foraging areas for the birding population, the USFWS is proposing a restoration effort to rebuild Breton Island to its pre-Katrina footprint.
This Data Series serves as an archive of processed interferometric-swath, single-beam bathymetry, and side-scan sonar data collected in the nearshore of Breton and Gosier Islands, NWR, Louisiana. The data were collected during two USGS cruises (USGS Field Activity Numbers 2014-314-FA and 2014-317-FA) in July and August 2014. Geographic Information System data products include a 100 meter-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee (FGDC) metadata.

作为屏障岛监测项目（Barrier Island Monitoring Project）的一部分，美国地质调查局（U.S. Geological Survey, USGS）圣彼得堡海岸与海洋科学中心的科学家于2014年7月至8月，在路易斯安那州布雷顿岛与戈西尔岛近岸开展了近岸地球物理调查。
为协助美国鱼类及野生动物管理局（United States Fish and Wildlife Service, USFWS）开展修复规划工作，美国地质调查局承接了针对尚德勒尔群岛南部物理环境相关基础问题的解答任务，涵盖地质、地貌与海洋学方向。该区域此前用于解答此类问题的基线数据要么不足，要么缺失。2014年夏季，美国地质调查局通过采集地球物理与沉积学数据，完成了全面的地质调查工作。
布雷顿岛坐落于路易斯安那州尚德勒尔群岛链的南端，是多种鸟类天然且具有全球重要性的筑巢庇护地，并于1904年被设立为布雷顿国家野生动物保护区（Breton National Wildlife Refuge, NWR）。自1920年以来，布雷顿岛的陆地面积已缩减90%，陆地流失归因于持续的相对海平面上升、沉积物补给减少以及风暴影响。多年来，布雷顿岛上的鸟类种群数量持续下降，尤以1998年乔治飓风与2015年卡特里娜飓风之后为甚，后者曾完全淹没该岛。尽管可栖息面积不断缩减，迁徙海鸟仍会返回并利用布雷顿岛。为防止该岛未来完全被淹没，同时为鸟类种群保护、稳定栖息地并提供更多筑巢与觅食区域，美国鱼类及野生动物管理局正提议开展修复工程，将布雷顿岛恢复至卡特里娜飓风前的范围。
本数据集系列为美国路易斯安那州国家野生动物保护区布雷顿岛与戈西尔岛近岸采集的经过处理的干涉条带测深（interferometric-swath bathymetry）、单波束测深（single-beam bathymetry）与侧扫声呐（side-scan sonar）数据的存档。这些数据由美国地质调查局于2014年7月和8月的两次科考航次（美国地质调查局野外活动编号：2014-314-FA与2014-317-FA）采集完成。地理信息系统（Geographic Information System, GIS）数据产品包括100米网格分辨率的插值测深格网表面、测线地图以及点数据文件。额外文件涵盖误差分析地图、野外活动采集系统日志以及正式的联邦地理数据委员会（Federal Geographic Data Committee, FGDC）元数据。