Airborne electromagnetic and magnetic survey of Delaware Bay and surrounding regions of New Jersey and Delaware, 2022 (ver 2.0, April 2025)

Airborne electromagnetic (AEM) and magnetic survey data were collected during July and August 2022 over a distance of 3,588.5 line kilometers covering Delaware Bay and surrounding regions in New Jersey and Delaware. Data were collected as part of the USGS Delaware River Basin Next Generation Water Observing Systems (NGWOS) project to improve understanding of groundwater salinity distributions near Delaware Bay. The survey was primarily funded by the USGS, with partial support through collaboration with the University of Delaware to extend data collection to parts of Rehoboth Bay and Indian River Bay. Data were acquired by SkyTEM Canada Inc. with the SkyTEM 304M time-domain helicopter-borne electromagnetic system together with a Geometrics G822A cesium vapor magnetometer. The survey was acquired at a nominal flight height of 30 - 40 m above terrain along parallel flight lines primarily oriented southwest-northeast and with nominal line spacing of 500 m over land and nearshore, and 3000 m over open-water parts of Delaware Bay. Several irregular flightlines were acquired along, and perpendicular to, nearby rivers to capture salinity patterns along these hydrologic flowpaths. Version 2.0 includes additional processed AEM data and inverted resistivity models.

2022年7—8月，研究团队完成了覆盖特拉华湾及新泽西州、特拉华州周边区域的航空电磁（Airborne Electromagnetic, AEM）与磁法测量数据采集工作，测线总长度达3588.5线千米。该数据系美国地质调查局（USGS）特拉华河流域下一代水观测系统（Next Generation Water Observing Systems, NGWOS）项目的成果，旨在深化对特拉华湾周边地下水盐度分布特征的认知。本次调查主要由美国地质调查局资助，同时通过与特拉华大学的合作，将数据采集范围拓展至雷霍博特湾与印第安河湾的部分区域。数据由SkyTEM Canada Inc.使用SkyTEM 304M时域直升机载电磁系统，搭配Geometrics G822A铯蒸气磁力仪完成采集。本次调查采用沿西南-东北走向的平行测线作业，标称飞行高度为距地形30~40米；陆上及近岸区域的标称测线间距为500米，特拉华湾开阔水域的标称测线间距则为3000米。为捕捉沿这些水文路径的盐度分布模式，团队还沿邻近河流及其垂直方向布设了若干不规则测线。本数据集2.0版本新增了经处理的航空电磁数据与反演电阻率模型。