Interferometric Swath Bathymetry Survey Tracklines Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM03)

As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in June of 2012. The overall objective of the study is to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). The collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of 3 consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years).
This report serves as an archive of processed interferometric swath and single-beam bathymetry data that were collected during two cruises (USGS Field Activity Numbers 12BIM03 and 12BIM04) along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana, in July of 2012. Geographic information system data products include a 50 m-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 metadata.

作为障壁岛演化研究项目（Barrier Island Evolution Research Project）的组成部分，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研人员于2012年6月在路易斯安那州尚德莱尔群岛（Chandeleur Islands）北部近岸海域开展了近岸地球物理勘测。本研究的总体目标是深入解析障壁岛地貌演化过程，尤其是在年际至跨年度时间尺度（1至5年）下塑造岛屿的风暴相关沉积与侵蚀作用。地球物理数据的采集将帮助我们厘清岛屿地质历史与现今地貌、沉积物分布之间的内在关联。本次测绘作业是该区域三项规划勘测的首项。针对这一快速变迁的障壁岛系统，连续三年逐年采集的高分辨率地球物理数据将形成一套独特的时间序列数据集，可显著推进该区域及其他海岸系统的分析与地貌学解译工作，进一步加深我们对短时间尺度（1至5年）内海岸响应与演化过程的理解。
本报告归档了2012年7月于路易斯安那州布雷顿国家野生动物保护区（Breton National Wildlife Refuge）尚德莱尔群岛北部海域，通过两次科考航次（美国地质调查局野外活动编号12BIM03与12BIM04）采集的经处理的干涉条带测深与单波束水深测量数据。地理信息系统（Geographic Information System, GIS）数据产品包含50米单元格尺寸的插值水深栅格表面、测线地图以及点数据文件。附加文件涵盖误差分析图、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。