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.

针对北卡罗来纳州东北部海岸带（覆盖范围自弗吉尼亚州假角（False Cape）至北卡罗来纳州卢考特角（Cape Lookout）），一项合作研究项目已完成相关调查，对区域内河口湾、障壁岛及大陆架内缘的第四纪地质框架开展了填绘工作。该研究成果可为理解不同时间尺度（从风暴事件至千年尺度）下地质框架、物理过程与海岸演化之间的关联提供基础支撑。本研究区域内的公园与海滩拥有极高的旅游吸引力，区域内分布多个沿海社区，并支撑着当地渔业发展，而上述所有活动均受海岸变化的影响。本研究项目获取的相关知识可用于缓解海岸灾害风险，并助力该动态海岸带的高效管理。
本区域填绘项目生成了两类空间数据集：高分辨率地球物理数据（水深测量（bathymetry）、后向散射强度（backscatter intensity）与地震反射（seismic reflection））与沉积学数据（岩心与抓取采样（core and 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、近岸海域及大陆架内缘，通过多次野外调查完成。沉积岩心采集工作覆盖大陆沿岸及障壁岛区域，大陆架内缘则同时采集了岩心与抓取样。本次数据采集工作由美国地质调查局（U.S. Geological Survey, USGS）联合东卡罗来纳大学（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）等多家机构共同完成。
大陆架内缘的高分辨率地球物理数据通过1999年至2004年间开展的6次独立调查采集完成，其中包括哈特拉斯角以北的4次USGS调查（1999-045-FA、2001-005-FA、2002-012-FA、2002-013-FA）以及哈特拉斯角以南的2次USGS调查（2003-003-FA、2004-003-FA），覆盖范围超过2600平方千米的大陆架内缘区域。1999年，研究团队在哈特拉斯角以北海域采用Furuno测深仪采集了单波束水深测量数据。其余所有大陆架内缘调查均采用SEA有限公司SwathPLUS 234-kHz测深声呐采集条带水深测量数据。在哈特拉斯角以北海域，研究团队采用Teledyne Benthos（Datasonics）SIS-1000系统采集了Chirp地震数据与侧扫声呐数据，并在1999-045-FA、2001-005-FA、2002-012-FA及2002-013-FA航次中采集了电火花震源（boomer）地震反射数据。在哈特拉斯角以南海域（2003-003-FA与2004-003-FA航次），研究团队采用Edgetech 512i采集Chirp地震数据，并搭配Klein 3000侧扫声呐系统开展数据采集。在4次USGS航次（1999-045-FA、2001-005-FA、2002-013-FA及2004-003-FA）中，研究团队采用Van Veen型抓取采样器采集了沉积样本；大陆架内缘的额外岩心数据则来自已发表的相关研究成果。
1996年，北卡罗来纳州地质调查局与矿产管理服务局（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心（vibracore）样本。美国陆军工程兵团分别于1995年8月（NDC航次岩心）与1995年7-8月（SNL航次岩心），在戴尔县近海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保存，并被用于本研究的地面验证工作。
弗吉尼亚海洋科学研究所完成了近岸海域的地球物理与岩心数据采集工作。本研究中近岸海域的定义为水深10米等深线至海岸线之间的区域。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、后向散射强度与Chirp地震数据，并于2005年5月与7月采集了振动岩心样本。
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USGS的合作研究项目之一，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心（rotasonic cores, OBX cores）样本，这些岩心分布于外班克斯岛及大陆沿岸区域。
USGS于2001年至2004年间通过6次航次（2001-013-FA、2002-015-FA、2003-005-FA、2003-042-FA、2004-005-FA及2004-006-FA），在阿尔伯马尔-帕姆利科河口湾系统内采集了第四纪地层的地震数据。除2003-042-FA航次采用Edgetech 424 Chirp系统与电火花震源系统外，其余航次均采用Geopulse电火花震源与Knudsen Engineering Limited（KEL）320BR Chirp系统开展数据采集。本研究区域涵盖阿尔伯马尔湾及其支流河口湾（如South河、Pungo河、Alligator河与Pasquotank河）、帕姆利科湾及其主干河口湾（如Neuse河与Pamlico河），以及障壁后海湾（如Currituck湾、Croatan湾、Roanoke湾、Core湾与Bogue湾）。