Point Shapefile of Electrical Conductance Geoprobe Locations Collected in August, 2005 in the Nauset Marsh Area of Cape Cod, Massachusetts

In order to test hypotheses about groundwater flow under and into estuaries and the Atlantic Ocean, geophysical surveys, geophysical probing, submarine groundwater sampling, and sediment coring were conducted by U.S. Geological Survey (USGS) scientists at Cape Cod National Seashore (CCNS) from 2004 through 2006. Coastal resource managers at CCNS and elsewhere are concerned about nutrients that are entering coastal waters via submarine groundwater discharge, which are contributing to eutrophication and harmful algal blooms. The research carried out as part of the study described here was designed, in part, to help refine assumptions required by earlier versions of models about the nature of submarine groundwater flow and discharge at CCNS. This study was conducted in four phases, with a variety of field techniques and equipment employed in each phase. Phase 1 consisted of continuous resistivity profiling (CRP) surveys of the entire study area conducted in 2004. Phase 2 consisted of CRP ground-truthing via resistivity probe measurements and submarine groundwater sampling from hydraulically-drive piezometers using a barge in the Salt Pond/Nauset Marsh area in 2005. Phase 3 consisted of supplemental detailed CRP surveys in the Salt Pond/Nauset Marsh area in 2006. Finally, Phase 4 consisted of sediment coring and porewater extraction in the Salt Pond/Nauset Marsh area later in 2006 to supplement the 2005 sampling.为验证河口下方及内部、大西洋之下的地下水流动相关假说，美国地质调查局（U.S. Geological Survey, USGS）的科研人员于2004至2006年间，在科德角国家海岸（Cape Cod National Seashore, CCNS）开展了地球物理勘探、地球物理探测、海底地下水采样与沉积物取芯工作。科德角国家海岸及其他区域的海岸资源管理者普遍担忧，通过海底地下水排泄进入近岸水体的营养物质会加剧富营养化与有害藻华的发生。本研究的相关设计工作，部分旨在完善早期模型版本中，关于科德角国家海岸海底地下水流动与排泄特征的必要假设。本研究共分为四个阶段，各阶段均采用了多样化的野外技术与设备：第一阶段为2004年针对整个研究区域开展的连续电阻率剖面（continuous resistivity profiling, CRP）勘探；第二阶段为2005年在盐池/诺塞特沼泽区域，借助驳船利用液压驱动测压管开展电阻率探针测量，以完成连续电阻率剖面的实地验证，并同步进行海底地下水采样；第三阶段为2006年在盐池/诺塞特沼泽区域开展的补充性精细连续电阻率剖面勘探；最后，第四阶段为2006年后期在该区域开展的沉积物取芯与孔隙水提取工作，以补充2005年的采样工作。