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系统，由一项合作研究项目开展系统研究，该项目完成了河口湾、障壁岛及大陆架内缘的第四纪地质格架（Quaternary geologic framework）填绘工作。该研究成果为理解不同时间尺度（从风暴事件到千年尺度）下地质格架、物理过程与海岸演化之间的耦合关系提供了基础依据。本研究区域内的公园与海滩承载大量游客，分布着多个沿海社区，同时支撑着当地渔业，上述所有业态均受到海岸变化的影响。本项目产出的研究成果可用于减缓海岸灾害风险，并为该动态海岸系统的精细化管理提供支撑。

本区域填绘项目生成了高分辨率地球物理（水深测量（bathymetry）、后向散射强度（backscatter intensity）与地震反射（seismic reflection））与沉积学（岩心（core）与抓斗取样（grab-sample））空间数据集。高分辨率地球物理数据通过多次勘测完成采集，覆盖范围涵盖障壁后河口湾系统、障壁岛群、近岸区域及大陆架内缘。沉积岩心采集工作覆盖大陆区域与障壁岛沿岸，而大陆架内缘则同步开展了岩心与抓斗取样工作。本次数据采集工作由美国地质调查局（USGS）联合东卡罗来纳大学（ECU）、北卡罗来纳地质调查局及弗吉尼亚海洋科学研究所（VIMS）等多家机构共同完成。

大陆架内缘的高分辨率地球物理数据通过1999年至2004年间开展的6次独立勘测完成采集，其中哈特拉斯角以北有4次USGS勘测：1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA；哈特拉斯角以南有2次USGS勘测：2003-003-FA与2004-003-FA，总覆盖面积超过2600平方千米的大陆架内缘区域。1999年，哈特拉斯角以北区域采用古野（Furuno）测深仪采集了单波束水深测量数据。其余所有大陆架内缘勘测均采用SEA有限公司SwathPLUS 234千赫兹测深声呐采集条带测深数据。哈特拉斯角以北区域采用泰莱达本特斯（Teledyne Benthos，原Datasonics）SIS-1000系统采集了啁啾地震数据与侧扫声呐数据，并在1999-045-FA、2001-005-FA、2002-012-FA及2002-013-FA四次勘测中采集了电火花地震反射数据。哈特拉斯角以南区域（2003-003-FA与2004-003-FA两次勘测）采用Edgetech 512i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。在四次USGS勘测（1999-045-FA、2001-005-FA、2002-013-FA及2004-003-FA）中，采用Van Veen抓斗取样器采集了沉积样本。大陆架内缘的补充沉积岩心数据来自已发表的相关研究成果。

1996年，北卡罗来纳地质调查局与矿产管理服务局（Minerals Management Service，对应MMS岩心）合作开展研究，在北卡罗来纳州纳格斯黑德、基尔迪夫尔斯与基蒂霍克近岸的大陆架内缘采集了振动岩心（vibracore）样本。美国陆军工程兵团于1995年8月（NDC岩心）及1995年7-8月（SNL岩心）在戴尔县近岸的大陆架内缘采集了振动岩心样本。上述岩心由北卡罗来纳地质调查局保管，并作为本次研究地面验证工作的一部分得到应用。

近岸地球物理数据与岩心数据由弗吉尼亚海洋科学研究所（VIMS）采集。本次研究中将近岸区域定义为10米等深线（isobath）与海岸线之间的范围。2002年6月至2004年5月期间，采集了高分辨率水深测量、后向散射强度与啁啾地震数据；2005年5月与7月则完成了振动岩心样本的采集工作。

外岸障壁岛沿岸采用探地雷达（GPR，ground-penetrating radar）系统采集了浅层地下地球物理数据。该数据由东卡罗来纳大学（ECU）于2002年至2005年间采集完成。北卡罗来纳地质调查局作为与美国地质调查局（USGS）合作研究项目的一部分，于2002年至2006年间通过5次钻探作业采集了旋转声波岩心（rotasonic cores，简称OBX岩心）样本。上述岩心分布于外岸区域与大陆区域内。

美国地质调查局（USGS）于2001年至2004年间通过6次勘测（2001-013-FA、2002-015-FA、2003-005-FA、2003-042-FA、2004-005-FA及2004-006-FA），完成了阿尔伯马尔-帕姆利科河口湾系统内第四纪地层的地震数据采集工作。本次研究区域涵盖阿尔伯马尔湾（Albemarle Sound）及其支流河口湾（如南河、庞戈河、短吻鳄河与帕斯科坦克河）、帕姆利科湾（Pamlico Sound）及其主干河口湾（如纽斯河与帕姆利科河），以及障壁后海湾（back-barrier sounds）（如库里蒂克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾）。除2003-042-FA勘测采用Edgetech 424啁啾系统与电火花系统外，其余勘测均采用Geopulse电火花系统与克努森工程有限公司（Knudsen Engineering Limited，缩写KEL）320BR啁啾系统。