Presenter: Bing-Yun Wu
Date: 2016/10/13
Abstract
Submarine groundwater discharge (SGD) connects land environments to coastal and offshore environments, which plays the important role in the hydrologic and biogeochemical cycles. A high-resolution, stationary geophysical and geochemical survey was conducted at Dor Beach, Israel, to investigate the shallow coastal hydrogeology and its control on the exchange of submarine groundwater with the shallow sea. Time-series resistivity profiles using a new 56 electrode (112-m long) cable produced detailed profiles of the fresh water/salt water interface and the subtle response of this interface to excursions and other forcing factors. Time-serie 222-Rn measurements of the adjacent coastal water column complemented the geophysical techniques and were modeled to yield integrated advective flow rates across the sediment/water interface. The study extrapolates these SGD estimates across a 100-m wide coastal zone implies that the Rn-derived SGD rate would equal∼7.1 m 3 d −1 per m of shoreline. Furthermore, simultaneous geochemical tracer studies and high-resolution resistivity measurements provide the complementary utility of these two techniques to study coastal exchange processes.
Reference
P. W. Swarzenski, W. C. Burnett, W. J. Greenwood, B. Herut, R. Peterson, N. Dimova, Y. Shalem, Y. Yechieli, and Y. Weinstein, “Combined time-series resistivity and geochemical tracer techniques to examine submarine groundwater discharge at Dor Beach, Israel”, Geophysical research letters, VOL. 33, L24405, 2006.
M. Bayani Cardenas, Peter B. Zamora, Fernando P. Siringan, Mark R. Lapus, Raymond S. Rodolfo, Gil S. Jacinto, Maria Lourdes San Diego‐McGlone, Cesar L. Villanoy, Olivia Cabrera, and Maria Isabel Senal, “Linking regional sources and pathways for submarine groundwater discharge at a reef by electrical resistivity tomography, 222Rn, and salinity measurements”, Geophysical research letters, VOL. 37, L16401, 2010.