Chirp navigation tracklines from USGS cruise 2001-005-FA along the inner continental shelf of northern North Carolina (isc2001005_tracklines.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.

北卡罗来纳州东北部沿岸系统（范围从美国弗吉尼亚州的假角（False Cape）至北卡罗来纳州的瞭望角（Cape Lookout））已由一项合作研究项目开展研究，该项目完成了河口湾（estuaries）、障壁岛（barrier islands）及大陆架内缘（inner continental shelf）的第四纪地质框架（Quaternary geologic framework）填图工作。本研究成果可为理解地质框架、物理过程与海岸演化之间的关联提供基础，其时间尺度涵盖从风暴事件到千年量级的多个维度。该研究区域的公园与海滩吸引了大量游客，沿岸分布多个沿海社区，并支撑着本地渔业，而上述所有活动均会受到海岸变化的影响。本研究项目获取的知识可用于减缓海岸灾害风险，并助力该动态沿岸系统的高效管理。
本区域填图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））及沉积（岩芯（core）与抓斗采样（grab-sample））空间数据集。高分辨率地球物理数据采集自障壁后河口湾系统内部、障壁岛群沿线、近岸区域及大陆架内缘的多次勘测。沉积岩芯采集于陆域及障壁岛沿线，而大陆架内缘同时采集了岩芯与抓斗采样样品。数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）与东卡罗来纳大学（East Carolina University, ECU）、北卡罗来纳州地质调查局、弗吉尼亚海洋科学研究所（Virginia Institute of Marine Science, VIMS）等多家机构合作完成。
大陆架内缘的高分辨率地球物理数据采集自1999年至2004年间开展的6次独立勘测（其中4次为美国地质调查局在哈特拉斯角以北开展的勘测：1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA；另外2次为哈特拉斯角以南的USGS勘测：2003-003-FA与2004-003-FA），覆盖了超过2600平方千米的大陆架内缘区域。1999年，研究人员使用古野（Furuno）测深仪采集了哈特拉斯角以北的单波束水深测量数据。其余所有大陆架内缘勘测均使用SEA有限公司的SwathPLUS 234kHz测深声呐采集条带测深数据。在哈特拉斯角以北的勘测（1999-045-FA、2001-005-FA、2002-012-FA及2002-013-FA航次）中，研究人员使用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，同时采集了boom地震反射数据（boomer seismic reflection data）。在哈特拉斯角以南的勘测（2003-003-FA与2004-003-FA航次）中，研究人员使用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及2004-003-FA）中，研究人员使用Van Veen采泥器（Van Veen grab sampler）采集了沉积样品。大陆架内缘的补充沉积岩芯数据来自已发表的前期研究成果。
1996年，北卡罗来纳州地质调查局与矿产管理局（Minerals Management Service, MMS cores）合作开展了一项研究，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近海的大陆架内缘采集了振动岩芯（vibracore）。美国陆军工程兵团于1995年8月（NDC岩芯）及1995年7-8月（SNL岩芯）在戴尔县近海的大陆架内缘采集了振动岩芯。上述岩芯由北卡罗来纳州地质调查局保存，并作为本次研究的地面验证环节的一部分被使用。
弗吉尼亚海洋科学研究所采集了近岸区域的地球物理与岩芯数据。本次研究中，近岸区域被定义为10米等深线与海岸线之间的区域。高分辨率水深测量、背散射强度及啁啾地震数据采集于2002年6月至2004年5月期间。振动岩芯样品采集于2005年5月与7月。
研究人员使用探地雷达（ground-penetrating radar, GPR）系统在外班克斯障壁岛沿线采集了浅部地下地球物理数据。该数据由东卡罗来纳大学于2002年至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年至2006年间通过5次钻探作业采集了旋转声波岩芯（rotasonic cores, OBX岩芯）。这些岩芯分布于外班克斯区域及陆域范围内。
2001年至2004年间，USGS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）采集了阿尔伯马尔-帕姆利科河口湾系统内第四纪地层的地震数据。除2003-042-FA航次使用Edgetech 424啁啾系统与boom系统外，其余勘测均使用Geopulse Boomer与Knudsen工程有限公司（Knudsen Engineering Limited, KEL）320BR啁啾系统。本次研究区域包括阿尔伯马尔湾（Albemarle Sound）及指定支流河口湾（如南河、庞戈河、短吻鳄河与帕斯夸坦克河）、帕姆利科湾（Pamlico Sound）及主干河口湾（如纽斯河与帕姆利科河），以及障壁后海湾（如库里蒂克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾）。