JPEG images of chirp seismic data from back-barrier research cruise 2002-015-FA collected by the U.S. Geological Survey

The northeastern North Carolina coastal system, from False Cape, Virginia, to Cape Lookout, North Carolina, has been studied by a cooperative research program that mapped the Quaternary geologic framework of the estuaries, barrier islands, and inner continental shelf. This information provides a basis to understand the linkage between geologic framework, physical processes, and coastal evolution at time scales from storm events to millennia. The study area attracts significant tourism to its parks and beaches, contains a number of coastal communities, and supports a local fishing industry, all of which are impacted by coastal change. Knowledge derived from this research program can be used to mitigate hazards and facilitate effective management of this dynamic coastal system.
This regional mapping project produced spatial datasets of high-resolution geophysical (bathymetry, backscatter intensity, and seismic reflection) and sedimentary (core and grab-sample) data. The high-resolution geophysical data were collected during numerous surveys within the back-barrier estuarine system, along the barrier island complex, in the nearshore, and along the inner continental shelf. Sediment cores were taken on the mainland and along the barrier islands, and both cores and grab samples were taken on the inner shelf. Data collection was a collaborative effort between the U.S. Geological Survey (USGS) and several other institutions including East Carolina University (ECU), the North Carolina Geological Survey, and the Virginia Institute of Marine Science (VIMS).
The high-resolution geophysical data of the inner continental shelf were collected during six separate surveys conducted between 1999 and 2004 (four USGS surveys north of Cape Hatteras: 1999-045-FA, 2001-005-FA, 2002-012-FA, 2002-013-FA, and two USGS surveys south of Cape Hatteras: 2003-003-FA and 2004-003-FA) and cover more than 2600 square kilometers of the inner shelf. Single-beam bathymetry data were collected north of Cape Hatteras in 1999 using a Furuno fathometer. Swath bathymetry data were collected on all other inner shelf surveys using a SEA, Ltd. SwathPLUS 234-kHz bathymetric sonar. Chirp seismic data as well as sidescan-sonar data were collected with a Teledyne Benthos (Datasonics) SIS-1000 north of Cape Hatteras along with boomer seismic reflection data (cruises 1999-045-FA, 2001-005-FA, 2002-012-FA and 2002-013-FA). An Edgetech 512i was used to collect chirp seismic data south of Cape Hatteras (cruises 2003-003-FA and 2004-003-FA) along with a Klein 3000 sidescan-sonar system. Sediment samples were collected with a Van Veen grab sampler during four of the USGS surveys (1999-045-FA, 2001-005-FA, 2002-013-FA, and 2004-003-FA). Additional sediment core data along the inner shelf are provided from previously published studies.
A cooperative study, between the North Carolina Geological Survey and the Minerals Management Service (MMS cores), collected vibracores along the inner continental shelf offshore of Nags Head, Kill Devils Hills and Kitty Hawk, North Carolina in 1996. The U.S. Army Corps of Engineers collected vibracores along the inner shelf offshore of Dare County in August 1995 (NDC cores) and July-August 1995 (SNL cores). These cores are curated by the North Carolina Geological Survey and were used as part of the ground validation process in this study.
Nearshore geophysical and core data were collected by the Virginia Institute of Marine Science. The nearshore is defined here as the region between the 10-m isobath and the shoreline. High-resolution bathymetry, backscatter intensity, and chirp seismic data were collected between June 2002 and May 2004. Vibracore samples were collected in May and July 2005.
Shallow subsurface geophysical data were acquired along the Outer Banks barrier islands using a ground-penetrating radar (GPR) system. Data were collected by East Carolina University from 2002 to 2005. Rotasonic cores (OBX cores) from five drilling operations were collected from 2002 to 2006 by the North Carolina Geological Survey as part of the cooperative study with the USGS. These cores are distributed throughout the Outer Banks as well as the mainland.
The USGS collected seismic data for the Quaternary section within the Albemarle-Pamlico estuarine system between 2001 and 2004 during six surveys (2001-013-FA, 2002-015-FA, 2003-005-FA, 2003-042-FA, 2004-005-FA, and 2004-006-FA). These surveys used Geopulse Boomer and Knudsen Engineering Limited (KEL) 320BR Chirp systems, except cruise 2003-042-FA, which used an Edgetech 424 Chirp and a boomer system. The study area includes Albemarle Sound and selected tributary estuaries such as the South, Pungo, Alligator, and Pasquotank Rivers; Pamlico Sound and trunk estuaries including the Neuse and Pamlico Rivers; and back-barrier sounds including Currituck, Croatan, Roanoke, Core, and Bogue.

美国弗吉尼亚州假角（False Cape）至北卡罗来纳州卢考特角（Cape Lookout）之间的北卡罗来纳州东北部海岸带系统，由一项合作研究项目开展了系统研究，完成了该区域河口湾（estuaries）、障壁岛（barrier islands）与内陆架（inner continental shelf）的第四纪（Quaternary）地质格架测绘。该研究成果可为理解不同时间尺度下（从风暴事件到千年尺度）地质格架、物理过程与海岸演化之间的关联提供基础支撑。本研究区域拥有多处公园与海滩，旅游业发达，分布有多个沿海社区，并支撑着当地渔业，上述产业均受海岸变化影响。本研究获取的相关知识可用于减缓海岸灾害风险，并助力该动态海岸带系统的精细化管理。
本区域测绘项目生成了高分辨率地球物理（水深测量（bathymetry）、背散射强度（backscatter intensity）与地震反射（seismic reflection））与沉积（岩芯与抓取采样（grab-sample））数据的空间数据集。高分辨率地球物理数据采集工作覆盖障壁后河口湾系统（back-barrier estuarine system）、障壁岛群（barrier island complex）、近岸带（nearshore）及内陆架区域，通过多次野外调查完成。沉积岩芯采集工作覆盖大陆沿岸与障壁岛区域，内陆架区域则同时采集了岩芯与抓取采样样品。本次数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）联合东卡罗来纳大学（East Carolina University, ECU）、北卡罗来纳州地质调查局以及弗吉尼亚海洋科学研究所（Virginia Institute of Marine Science, VIMS）共同完成。
内陆架的高分辨率地球物理数据采集工作于1999年至2004年间通过6次独立调查完成：其中哈特拉斯角（Cape Hatteras）以北区域开展了4次USGS调查（编号分别为1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA），哈特拉斯角以南区域开展了2次USGS调查（编号分别为2003-003-FA与2004-003-FA），整体覆盖面积超过2600平方千米的内陆架区域。1999年，哈特拉斯角以北区域采用古野测深仪（Furuno fathometer）完成了单波束水深测量（single-beam bathymetry）数据采集。其余内陆架调查均采用SEA有限公司SwathPLUS 234千赫测深声呐完成多波束水深测量（swath bathymetry）数据采集。在哈特拉斯角以北的4次调查（编号1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA）中，采用Teledyne Benthos（Datasonics）SIS-1000系统采集了啁啾地震数据（chirp seismic data）与侧扫声呐（sidescan-sonar）数据，并同步获取了电火花地震反射（boomer seismic reflection）数据。哈特拉斯角以南的2次调查（编号2003-003-FA与2004-003-FA）则采用Edgetech 512i系统采集啁啾地震数据，并搭配Klein 3000侧扫声呐系统开展数据采集。在4次USGS调查（编号1999-045-FA、2001-005-FA、2002-013-FA与2004-003-FA）中，采用范维恩抓取采样器（Van Veen grab sampler）完成了沉积样品采集。内陆架区域的补充沉积岩芯数据来自已发表的相关研究成果。
1996年，北卡罗来纳州地质调查局与矿产管理局（Minerals Management Service, MMS）联合开展合作研究，在北卡罗来纳州纳格斯黑德、基尔迪维尔希尔斯与基蒂霍克附近的内陆架海域采集了振动岩芯（vibracore）样品（MMS岩芯）。1995年8月与1995年7-8月，美国陆军工程兵团分别在戴尔县附近的内陆架海域采集了振动岩芯样品（分别标记为NDC岩芯与SNL岩芯）。上述岩芯由北卡罗来纳州地质调查局负责归档保存，并作为本次研究的地面验证数据的一部分。
近岸带地球物理数据与岩芯数据由弗吉尼亚海洋科学研究所完成采集。本研究中近岸带定义为10米等深线（isobath）与海岸线之间的区域。2002年6月至2004年5月间，完成了高分辨率水深测量、背散射强度与啁啾地震数据采集。振动岩芯样品采集工作于2005年5月与7月完成。
外滩群岛（Outer Banks）障壁岛区域的浅层地下地球物理数据采用探地雷达（ground-penetrating radar, GPR）系统完成采集。该数据由东卡罗来纳大学于2002年至2005年间采集完成。2002年至2006年间，北卡罗来纳州地质调查局作为与USGS合作研究的一部分，通过5次钻探作业采集了旋转声波岩芯（rotasonic cores, OBX岩芯）。该批岩芯分布于外滩群岛及大陆沿岸区域。
2001年至2004年间，USGS通过6次调查（编号分别为2001-013-FA、2002-015-FA、2003-005-FA、2003-042-FA、2004-005-FA与2004-006-FA）完成了阿尔伯马尔-帕姆利科河口湾系统（Albemarle-Pamlico estuarine system）内第四纪地层的地震数据采集。除编号2003-042-FA的调查航次采用Edgetech 424啁啾系统与电火花系统外，其余航次均采用Geopulse电火花系统与Knudsen工程有限公司（Knudsen Engineering Limited, KEL）320BR啁啾系统开展数据采集。本次研究区域涵盖阿尔伯马尔湾及其支流河口湾（包括南河、庞戈河、短吻鳄河与帕斯夸坦克河）、帕姆利科湾及其干流河口湾（包括纽斯河与帕姆利科河），以及障壁后海湾（包括库里蒂克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾）。