JPEG images of chirp seismic data from inner shelf U.S. Geological Survey research cruise 1999-045-FA collected by the U.S. Geological Survey

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.针对从弗吉尼亚州假角（False Cape）到北卡罗来纳州卢考特角（Cape Lookout）的北卡罗来纳州东北部海岸带，一项合作研究项目已完成相关研究工作，该项目完成了河口湾（estuary）、障壁岛（barrier island）及陆架内缘（inner continental shelf）的第四纪地质框架（Quaternary geologic framework）填绘。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，其时间尺度覆盖风暴事件至千年跨度。该研究区域的公园与海滩吸引了大量游客，沿岸分布着多个海岸社区，并支撑着当地渔业，而所有这些都受到海岸变化的影响。本项目获得的研究认知可用于减缓灾害风险，并助力该动态海岸带的高效管理。 本区域填绘项目生成了高分辨率地球物理（high-resolution geophysical data）与沉积（sedimentary data）数据的空间数据集，其中地球物理数据涵盖水深测量（bathymetry）、背散射强度（backscatter intensity）与地震反射（seismic reflection），沉积数据包含岩心（core）与抓取采样（grab-sample）数据。高分辨率地球物理数据采集工作覆盖障壁后河口湾系统、障壁岛群、近岸区域及陆架内缘的多次勘测。沉积岩心采样在大陆及障壁岛沿线开展，而岩心与抓取采样均在陆架内缘实施。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）、北卡罗来纳地质调查局以及弗吉尼亚海洋科学研究所（Virginia Institute of Marine Science, VIMS）。 陆架内缘的高分辨率地球物理数据采集工作于1999年至2004年间分六次勘测完成：其中四次为哈特拉斯角（Cape Hatteras）以北的USGS勘测（编号分别为1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA），两次为哈特拉斯角以南的USGS勘测（编号分别为2003-003-FA与2004-003-FA），覆盖面积超过2600平方千米的陆架内缘区域。1999年，研究人员使用Furuno测深仪在哈特拉斯角以北采集单波束水深测量数据。其余所有陆架内缘勘测均使用SEA有限公司的SwathPLUS 234-kHz测深声呐采集条带测深数据。在哈特拉斯角以北的四次勘测（1999-045-FA、2001-005-FA、2002-012-FA与2002-013-FA）中，研究人员使用Teledyne Benthos（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（boomer seismic reflection）数据。在哈特拉斯角以南的两次勘测（2003-003-FA与2004-003-FA）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。研究人员在四次USGS勘测（1999-045-FA、2001-005-FA、2002-013-FA与2004-003-FA）中使用范维恩抓取采样器（Van Veen grab sampler）采集沉积样品。陆架内缘的额外沉积岩心数据来自已发表的过往研究。 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、基尔迪维尔希尔斯与基蒂霍克近海的陆架内缘采集振动岩心（vibracore）样品。美国陆军工程兵团于1995年8月（NDC岩心）与1995年7-8月（SNL岩心）在戴尔县近海的陆架内缘采集振动岩心样品。这些岩心由北卡罗来纳地质调查局保存，并作为本次研究的地面验证数据的一部分被使用。 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心数据。本次研究中将近岸定义为10米等深线（10-m isobath）与海岸线之间的区域。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、背散射强度与啁啾地震数据。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，在外班克斯障壁岛沿线使用探地雷达（ground-penetrating radar, GPR）系统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，在五次钻探作业中采集了旋转声波岩心（OBX岩心），作为与USGS合作研究的一部分。这些岩心分布在外班克斯及大陆区域。 美国地质调查局于2001年至2004年间，分六次勘测（编号分别为2001-013-FA、2002-015-FA、2003-005-FA、2003-042-FA、2004-005-FA与2004-006-FA），在阿尔伯马尔-帕姆利科河口湾系统内采集第四纪地层的地震数据。本次勘测使用Geopulse电火花与Knudsen Engineering有限公司（Knudsen Engineering Limited, KEL）320BR啁啾系统，仅2003-042-FA勘测使用Edgetech 424啁啾系统与电火花系统。本研究区域包括阿尔伯马尔湾及相关支流河口湾（如南河、庞戈河、短吻鳄河与帕斯科坦克河）、帕姆利科湾及主干河口湾（如纽斯河与帕姆利科河），以及障壁后海湾（如科里塔克湾、克罗阿坦湾、罗阿诺克湾、科尔湾与博格湾）。