Martin A Briggs¹, Chen Wang², Frederick David Day-Lewis¹, Kenneth Hurst Williams³, Wenming Dong⁴ and John W Lane Jr¹, (1)USGS Hydrogeophysics Branch, Storrs, CT, United States, (2)Rutgers University, Department of Earth & Environmental Sciences, Newark, NJ, United States, (3)Lawrence Berkeley National Laboratory, Earth and Environmental Sciences, Berkeley, CA, United States, (4)Lawrence Berkeley National Laboratory, Berkeley, CA, United States