Chirp navigation tracklines from USGS cruise 2002-013-FA along the inner continental shelf of northern North Carolina (isc2002013_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.

本研究针对美国北卡罗来纳州东北部海岸带系统（范围涵盖弗吉尼亚州假角（False Cape）至北卡罗来纳州卢考特角（Cape Lookout））开展，由合作研究项目完成了河口（estuaries）、障壁岛（barrier islands）及内陆陆架（inner continental shelf）的第四纪地质格架（Quaternary geologic framework）填图工作。该研究成果可为理解地质格架、物理过程与海岸演化之间的关联提供基础，研究时间尺度覆盖风暴事件至千年量级。该研究区域内的公园与海滩吸引了大量游客，分布有多个沿海社区，并支撑着当地渔业，上述所有活动均受到海岸变化的影响。本项目获取的研究成果可用于减缓海岸灾害风险，并助力该动态海岸带系统的有效管理。

本区域填图项目生成了多套空间数据集，包含高分辨率地球物理（水深测量（bathymetry）、背散射强度（backscatter intensity）及地震反射（seismic reflection））与沉积（岩心（core）与抓取采样（grab-sample））数据。高分辨率地球物理数据采集于障壁岛后方河口系统、障壁岛群沿岸、近岸区域及内陆陆架的多次勘测工作中。沉积岩心采集于大陆及障壁岛沿岸，而岩心与抓取采样样品均采集于内陆陆架。数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）与包括东卡罗来纳大学（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）在内的多家机构合作完成。

内陆陆架的高分辨率地球物理数据采集于1999年至2004年间开展的6次独立勘测中：其中4次为哈特拉斯角（Cape Hatteras）以北的美国地质调查局勘测（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美国地质调查局勘测（2003-003-FA与2004-003-FA），覆盖面积超过2600平方千米的内陆陆架区域。1999年，研究人员采用Furuno测深仪采集了哈特拉斯角以北的单波束水深测量数据。其余所有内陆陆架勘测均采用SEA有限公司SwathPLUS 234-kHz测深声呐采集条带水深测量数据。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，并在1999-045-FA、2001-005-FA、2002-012-FA及2002-013-FA航次中采集了电火花地震反射数据。在哈特拉斯角以南的2003-003-FA与2004-003-FA航次中，研究人员采用Edgetech 512i系统采集啁啾地震数据，并搭配Klein 3000侧扫声呐系统。研究人员在4次美国地质调查局勘测（1999-045-FA、2001-005-FA、2002-013-FA及2004-003-FA）中采用Van Veen抓取采样器采集了沉积样品。内陆陆架的额外岩心数据来自已发表的过往研究。

北卡罗来纳州地质调查局与矿产管理服务局（Minerals Management Service, MMS）合作开展的一项研究，于1996年在北卡罗来纳州纳格斯黑德（Nags Head）、基尔迪维尔希尔斯（Kill Devils Hills）与基蒂霍克（Kitty Hawk）近海的内陆陆架采集了振动岩心（vibracore）样品。1995年8月（NDC岩心）与1995年7-8月（SNL岩心），美国陆军工程兵团（U.S. Army Corps of Engineers）在戴尔县近海的内陆陆架采集了振动岩心样品。上述岩心由北卡罗来纳州地质调查局保存，并作为本研究地面验证工作的一部分得到应用。

弗吉尼亚海洋科学研究所采集了近岸地球物理与岩心数据。本研究中将近岸定义为10米等深线与岸线之间的区域。2002年6月至2004年5月间，研究人员采集了高分辨率水深测量、背散射强度及啁啾地震数据。2005年5月与7月，研究人员采集了振动岩心样品。

东卡罗来纳大学于2002年至2005年间，沿外滩群岛（Outer Banks）障壁岛采集了浅地下地球物理数据，所用设备为探地雷达（ground-penetrating radar, GPR）系统。北卡罗来纳州地质调查局于2002年至2006年间，在5次钻探作业中采集了旋转声波岩心（rotasonic cores，OBX岩心），作为与美国地质调查局合作研究的一部分。上述岩心分布于外滩群岛及大陆区域。

美国地质调查局于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-帕姆利科河口系统（Albemarle-Pamlico estuarine system）内第四纪地层的地震数据采集工作。除2003-042-FA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电火花与Knudsen Engineering Limited（KEL）320BR啁啾系统。本研究区域涵盖阿尔伯马尔湾及南河、庞戈河、阿利加特河与帕斯科坦克河等典型支流河口；帕姆利科湾及纽斯河、帕姆利科河等干流河口；以及科里塔克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾等障壁岛后方海湾。