Chirp shotpoint navigation from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isc2001005_shots.shp)

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.

本研究聚焦美国北卡罗来纳州东北部海岸系统，范围涵盖弗吉尼亚州假角（False Cape）至北卡罗来纳州瞭望角（Cape Lookout）之间的海域，由一项合作研究计划开展，该计划对河口、障壁岛与内大陆架的第四纪地质格架（Quaternary geologic framework）完成了系统制图。该研究成果为理解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内在关联提供了核心支撑。本研究区的公园与海滩拥有大量游客，沿岸分布诸多滨海社区，同时支撑起本地渔业，上述产业均受海岸变化的直接影响。本研究项目所得成果可用于减缓海岸灾害风险，并助力该动态海岸系统的高效管理。

本区域制图项目生成了高分辨率地球物理（水深测量（bathymetry）、反向散射强度（backscatter intensity）、地震反射（seismic reflection））与沉积（岩芯（core）与抓取采样（grab-sample））空间数据集。高分辨率地球物理数据采集于障壁后河口系统、障壁岛群、近岸区域以及内大陆架的多次勘测中。沉积岩芯采集于陆域与障壁岛沿岸，而岩芯与抓取采样均在内大陆架区域获取。本次数据采集由美国地质调查局（U.S. Geological Survey, USGS）与多家合作机构共同完成，包括东卡罗来纳大学（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）。

内大陆架的高分辨率地球物理数据采集于1999至2004年间的6次独立勘测中（哈特拉斯角以北的4次USGS勘测：1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA，以及哈特拉斯角以南的2次USGS勘测：2003-003-FA与2004-003-FA），覆盖内大陆架超过2600平方千米的区域。1999年，哈特拉斯角以北区域采用古野（Furuno）测深仪采集单波束水深数据。其余所有内大陆架勘测均采用SEA有限公司的SwathPLUS 234kHz测深声呐采集多波束水深数据。哈特拉斯角以北区域的啁啾地震（chirp seismic）数据与侧扫声呐（sidescan-sonar）数据采用Teledyne Benthos（Datasonics）SIS-1000采集，同时在1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA航次中采集了boom地震反射数据。哈特拉斯角以南的2003-003-FA与2004-003-FA航次中，采用Edgetech 512i采集啁啾地震数据，并搭配Klein 3000侧扫声呐系统。在4次USGS勘测（1999-045-FA、2001-005-FA、2002-013-FA与2004-003-FA）中，采用Van Veen抓取采样器采集沉积物样本。内大陆架的额外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岩芯）合作开展研究，在北卡罗来纳州纳格斯黑德、基尔迪夫尔斯山与基蒂霍克近海的内大陆架区域采集振动岩芯（vibracore）。美国陆军工程兵团于1995年8月（NDC岩芯）与1995年7-8月（SNL岩芯）在戴尔县近海的内大陆架区域采集振动岩芯。上述岩芯由北卡罗来纳州地质调查局统一保存，并作为本次研究地面验证工作的一部分。

近岸带地球物理与岩芯数据由弗吉尼亚海洋科学研究所采集。本次研究中，近岸带定义为10米等深线与海岸线之间的区域。高分辨率水深、反向散射强度与啁啾地震数据采集于2002年6月至2004年5月间。振动岩芯样本采集于2005年5月与7月。

外岸（Outer Banks）障壁岛沿岸采用探地雷达（ground-penetrating radar, GPR）系统采集浅层地下地球物理数据，该数据由东卡罗来纳大学于2002至2005年间采集。作为与USGS合作研究的一部分，北卡罗来纳州地质调查局于2002至2006年间通过5次钻探作业采集旋转声波岩芯（OBX岩芯），这些岩芯分布于外岸与陆域各地。

USGS于2001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与2004-006-FA）采集阿尔伯马尔-帕姆利科河口系统内第四纪剖面的地震数据。除2003-042-FA航次采用Edgetech 424啁啾系统与boom系统外，其余航次均采用Geopulse Boom与Knudsen Engineering有限公司（KEL）320BR啁啾系统。本次研究区域包括阿尔伯马尔湾（Albemarle Sound）及其支流河口（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（如纽斯河与帕姆利科河），以及障壁后海湾（如库里塔克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾）。