Water quality data collection in shallow water areas can be a challenging task. Obstacles encountered in such environments include difficulty in covering large territories and the presence of inaccessible areas due to a variety of reasons such as a soft bottom or contamination. There is also a high probability of disturbing the test area while placing the sensors. This paper describes a NASA-fu...

Atrazine has been identified in at least 20 of the 1,636 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2003). However, the number of sites evaluated for atrazine is not known. The frequency for these sites within the United States can be seen in Figure 6-1. Of these sites, all 20 are located within the United States and none are lo...

This thesis consists of three papers examining problems related to the crustal structure, isostasy and subsidence history of aseismic ridges and mid-plate island chains. Analysis of gravity and bathymetry data across the Ninetyeast and eastern Walvis Ridges indicates these features are locally compensated by an overthickening of the oceanic crust. Maximum crustal thicknesses are 15-30 km. The w...

1 Abstract We present results of self-consistent experiments of basin formation by extension and basin inversion through subsequent contraction. Our viscous-plastic finite element models include feedback interactions between crustal deformation, the development of local shear zones, and sedimentation and erosion. The extensional basins show a high degree of sensitivity to crustal strain softeni...

The number of broa.dband three-component seismic stations in southern California. has more tb an tripled recently. In th is study we use the teleseismic receiver function technique to determine the crustal thicknesses and Vp / Vs ratios for th ese stations and map out t he lateral variation of Moho dept h under southern California. It is shown t hat a. receiver function can provide a very good ...