Chirp shotpoint navigation (from USGS cruise 2003-005-FA from Pamlico Sound, North Carolina (bbc2003005_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.

以弗吉尼亚州假角（False Cape）至北卡罗来纳州卢考特角（Cape Lookout）为范围的美国北卡罗来纳州东北部海岸系统，已由一项合作研究计划开展系统性研究，该计划完成了河口湾、障壁岛（barrier islands）与大陆架内缘（inner continental shelf）的第四纪地质框架（Quaternary geologic framework）测绘工作。
该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支撑，研究时间尺度覆盖从风暴事件到千年尺度的范畴。
本研究区域的公园与海滩吸引了大量游客，区域内分布有多个沿海社区，并支撑着本地渔业，而上述所有对象均受海岸变化的影响。
本研究计划所获取的相关知识，可用于减缓海岸灾害风险，并助力该动态海岸系统的精细化管理。

本区域测绘项目生成了两类空间数据集：高分辨率地球物理数据（含水深测量（bathymetry）、背散射强度（backscatter intensity）与地震反射（seismic reflection））以及沉积学数据（含岩心（core）与抓斗采样（grab-sample）数据）。
高分辨率地球物理数据的采集工作，覆盖了障壁后河口湾系统、障壁岛群、近岸区域以及大陆架内缘的多轮勘测。
岩心采样工作在大陆区域与障壁岛沿线开展，而大陆架内缘则同时采集了岩心与抓斗采样样本。
本次数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）与多家合作机构共同完成，合作方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）。

大陆架内缘的高分辨率地球物理数据采集工作，于1999年至2004年间通过六轮独立勘测完成：其中四轮为美国地质调查局在哈特拉斯角以北开展的勘测（编号分别为1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA），另外两轮为其在哈特拉斯角以南开展的勘测（编号分别为2003-003-FA与2004-003-FA），覆盖面积超过2600平方千米的大陆架内缘区域。
1999年，研究团队使用古野（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采用SEA有限公司的SwathPLUS 234kHz测深声呐采集条带测深数据。
在1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA这四轮勘测中，研究团队使用泰莱达因本托斯（Datasonics）SIS-1000采集了哈特拉斯角以北的啁啾地震（Chirp seismic）数据与侧扫声呐（sidescan-sonar）数据，并同步采集了电火花地震反射（boomer seismic reflection）数据。
在2003-003-FA与2004-003-FA这两轮勘测中，研究团队使用Edgetech 512i设备采集哈特拉斯角以南的啁啾地震数据，并搭配Klein 3000侧扫声呐系统开展数据采集工作。
在四轮美国地质调查局勘测（1999-045-FA、2001-005-FA、2002-013-FA与2004-003-FA）中，研究团队使用范·维恩（Van Veen）抓斗采样器采集了沉积样本。
大陆架内缘的补充岩心数据来源于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）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近岸的大陆架内缘采集了振动岩心（vibracore）样本，相关岩心被命名为MMS岩心。
美国陆军工程兵团于1995年8月（采集的振动岩心被命名为NDC岩心）以及1995年7-8月（采集的振动岩心被命名为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州地质调查局负责保管，并作为本次研究中地面验证工作的一部分得以应用。

弗吉尼亚海洋科学研究所（VIMS）负责采集近岸区域的地球物理数据与岩心样本。
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水域及陆地区域。
研究团队于2002年6月至2004年5月间采集了高分辨率水深测量、背散射强度与啁啾地震数据。
振动岩心样本采集工作于2005年5月与7月完成。

研究团队采用探地雷达（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。
该数据采集工作由东卡罗来纳大学于2002年至2005年间完成。
作为与美国地质调查局合作研究的一部分，北卡罗来纳州地质调查局于2002年至2006年间通过五次钻探作业采集了旋转声波岩心（Rotasonic cores, OBX岩心），相关岩心分布于外班克斯区域与大陆区域各处。

美国地质调查局于2001年至2004年间通过六轮勘测（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内第四纪地层的地震数据采集工作。
除2003-042-FA轮勘测采用Edgetech 424啁啾系统与电火花震源系统外，其余勘测均采用Geopulse电火花震源与克努森工程有限公司（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（如南河、庞戈河、短吻鳄河与帕斯科坦克河）、帕姆利科湾及其主干河口湾（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）。