Chirp shotpoint navigation from USGS cruise 2004-005-FA from Pamlico Sound, North Carolina (bbc2004005_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.

美国北卡罗来纳州东北部海岸系统，涵盖弗吉尼亚州假角（False Cape）至北卡罗来纳州卢考特角（Cape Lookout）范围，已纳入一项合作研究计划的研究范畴，该计划完成了河口、障壁岛及内陆架第四纪（Quaternary）地质框架的测绘工作。该研究成果为理解地质框架、物理过程与海岸演化在风暴事件至千年尺度上的关联提供了基础。本研究区域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，所有这些均受到海岸变化的影响。本研究计划所获知识可用于减缓灾害风险，并助力该动态海岸系统的有效管理。
本区域制图项目生成了高分辨率地球物理（水深测量（bathymetry）、后向散射强度（backscatter intensity）与地震反射（seismic reflection））与沉积（岩心（core）、抓斗采样（grab-sample））数据的空间数据集。高分辨率地球物理数据是在障壁河口系统、障壁岛群、近岸区域及内陆架的多次勘测中采集的。岩心样品采集于大陆及障壁岛，内陆架区域则同时采集了岩心与抓斗采样样品。数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）与其他多家机构合作完成，包括东卡罗来纳大学（East Carolina University, ECU）、北卡罗来纳地质调查局以及弗吉尼亚海洋科学研究所（Virginia Institute of Marine Science, VIMS）。
内陆架的高分辨率地球物理数据采集于1999年至2004年间的6次独立勘测中，其中哈特拉斯角（Cape Hatteras）以北的4次USGS勘测对应航次编号为1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA，哈特拉斯角以南的2次USGS勘测对应航次编号为2003-003-FA与2004-003-FA，整体覆盖超过2600平方千米的内陆架区域。1999年，研究团队使用古野（Furuno）测深仪在哈特拉斯角以北采集了单波束水深测量数据。其余所有内陆架勘测均采用SEA有限公司的SwathPLUS 234kHz测深声呐，采集条带测深数据。在哈特拉斯角以北区域，研究团队使用泰莱达因·本托斯（Teledyne Benthos，即Datasonics）SIS-1000采集啁啾地震（chirp seismic）数据与侧扫声呐（sidescan-sonar）数据，同时采集电火花地震反射数据，对应航次包括1999-045-FA、2001-005-FA、2002-012-FA及2002-013-FA。在哈特拉斯角以南区域，对应航次为2003-003-FA与2004-003-FA，研究团队使用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，使用范·维恩抓斗采样器（Van Veen grab sampler）采集了沉积样品。内陆架的额外岩心数据来自已发表的既往研究成果。
北卡罗来纳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）近海的内陆架上采集了振动岩心（vibracore）样品。美国陆军工程兵团（U.S. Army Corps of Engineers）于1995年8月（采集的岩心标记为NDC岩心）及1995年7-8月（采集的岩心标记为SNL岩心），在戴尔县（Dare County）近海的内陆架上采集了振动岩心样品。上述岩心均由北卡罗来纳地质调查局归档保存，并作为本研究地面验证过程的组成部分得到应用。
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。本研究中近岸区域被定义为10米等深线与海岸线之间的范围。2002年6月至2004年5月间，研究团队采集了高分辨率水深测量数据、后向散射强度数据与啁啾地震数据。2005年5月与7月，采集了振动岩心样品。
东卡罗来纳大学于2002年至2005年间，使用探地雷达（ground-penetrating radar, GPR）系统沿外岸（Outer Banks）障壁岛采集了浅地表地球物理数据。北卡罗来纳地质调查局于2002年至2006年间，在与USGS的合作研究中，从5次钻探作业中获取了旋转声波岩心（rotasonic cores，即OBX岩心）。这些岩心分布于外岸及大陆区域。
美国地质调查局于2001年至2004年间的6次勘测中，在阿尔伯马尔-帕姆利科河口系统（Albemarle-Pamlico estuarine system）内采集了第四纪地层的地震数据，对应航次编号为2001-013-FA、2002-015-FA、2003-005-FA、2003-042-FA、2004-005-FA及2004-006-FA。除2003-042-FA航次使用Edgetech 424啁啾系统与电火花系统外，其余航次均采用Geopulse电火花系统与克努森工程有限公司（Knudsen Engineering Limited, KEL）320BR啁啾系统。本研究区域包括阿尔伯马尔湾（Albemarle Sound）及南河、庞戈河、阿利加托河与帕斯科坦克河等选定的支流河口；帕姆利科湾（Pamlico Sound）及纽斯河、帕姆利科河等主干河口；以及库里塔克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾等障壁后海湾。