首页 | 本学科首页   官方微博 | 高级检索  
     


Marine electrical resistivity imaging of submarine groundwater discharge: sensitivity analysis and application in Waquoit Bay, Massachusetts, USA
Authors:Rory D. Henderson  Frederick D. Day-Lewis  Elena Abarca  Charles F. Harvey  Hanan N. Karam  Lanbo Liu  John W. Lane Jr.
Affiliation:1. US Geological Survey, Office of Groundwater, Branch of Geophysics, 11 Sherman Place, Unit 5015, Storrs, CT, 06269, USA
2. Center for Integrative Geosciences, University of Connecticut, Beach Hall, Unit 2045, Storrs, CT, 06269, USA
3. Department of Civil and Environmental Engineering, MIT, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
Abstract:Electrical resistivity imaging has been used in coastal settings to characterize fresh submarine groundwater discharge and the position of the freshwater/salt-water interface because of the relation of bulk electrical conductivity to pore-fluid conductivity, which in turn is a function of salinity. Interpretation of tomograms for hydrologic processes is complicated by inversion artifacts, uncertainty associated with survey geometry limitations, measurement errors, and choice of regularization method. Variation of seawater over tidal cycles poses unique challenges for inversion. The capabilities and limitations of resistivity imaging are presented for characterizing the distribution of freshwater and saltwater beneath a beach. The experimental results provide new insight into fresh submarine groundwater discharge at Waquoit Bay National Estuarine Research Reserve, East Falmouth, Massachusetts (USA). Tomograms from the experimental data indicate that fresh submarine groundwater discharge may shut down at high tide, whereas temperature data indicate that the discharge continues throughout the tidal cycle. Sensitivity analysis and synthetic modeling provide insight into resolving power in the presence of a time-varying saline water layer. In general, vertical electrodes and cross-hole measurements improve the inversion results regardless of the tidal level, whereas the resolution of surface arrays is more sensitive to time-varying saline water layer.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号