نتایج جستجو برای: shallow subsurface structures
تعداد نتایج: 502856 فیلتر نتایج به سال:
[1] Based on the diffusion equation and Darcy’s law, Criss and Winston (2008b) developed the one-parameter analytical subsurface flow diffusion hydrograph model to represent the theory of rapid displacement of ‘‘old’’ aquifer water and shallow pore water following rainfall events. We developed a two-parameter analytical surface flow diffusion hydrograph model for urban or other basins that gene...
Conservation tillage has significant potential as a water management tool for cotton production on sandy, drought-prone soils. Plant residue remaining at the soil surface from prior crops serves as a vapor barrier against water loss, reduces raindrop impact energy, slows surface runoff, and often increases infiltration. By increasing infiltration, the potential for greater plant-available water...
[1] The newly developed wave equation poststack depth migration method for receiver function imaging is applied to study the subsurface structures of the Japan subduction zone using the Fundamental Research on Earthquakes and Earth’s Interior Anomalies (FREESIA) broadband data. Three profiles are chosen in the subsurface imaging, two in northeast (NE) Japan to study the subducting Pacific plate...
Detailed information about the spatial distribution of subsurface properties is important in many fields. One method that can image the seismic velocity structure of the shallow subsurface is crosswell seismic tomography. By including rays traveling from the boreholes to the surface, the angular coverage of crosswell tomograms can be significantly improved. We investigated the effects of these ...
We report results from a field survey performed on a recently discovered impact field in the southwestern Egyptian desert, using a 270 MHz Ground-Penetrating Radar (GPR). This hyperarid region has significant similarities to the Martian heavily eroded mid-latitude cratered terrains in terms of crater density, size, and geomorphology. Profiles across small-buried craters revealed a coherent sequ...
In November 2013, a series of earthquakes began along a mapped ancient fault system near Azle, Texas. Here we assess whether it is plausible that human activity caused these earthquakes. Analysis of both lake and groundwater variations near Azle shows that no significant stress changes were associated with the shallow water table before or during the earthquake sequence. In contrast, pore-press...
The complex dynamics that lead to the emergence of active regions on the sun are poorly understood. One possibility is that magnetic structures (flux tubes, etc.) rise from below the surface by self induction and convection that lead to the formation of active regions and sunspots on the solar surface. For space weather forecasting, one would like to detect the subsurface structures before they...
A corrosive environment leaves in-service conductive structures prone to subsurface corrosion which poses a severe threat to the structural integrity. It is indispensable to detect and quantitatively evaluate subsurface corrosion via non-destructive evaluation techniques. Although the gradient-field pulsed eddy current technique (GPEC) has been found to be superior in the evaluation of corrosio...
The exchange of groundand surface water plays a crucial role in a variety of practically relevant processes ranging from flood protection measures to preservation of ecosystem health in natural and human-impacted water resources systems. Commonly accepted models are based on the shallow water equations for overland flow and the Richards equation for saturated–unsaturated subsurface flow with su...
We designed experiments to evaluate the fate of the addition of wastewater-borne nutrients injected into the shallow subsurface in the Florida Keys. During three different experiments, either bulk unlabeled phosphate, radio-labeled phosphate Ž 3y. Ž 1y. Ž PO , or bulk unlabeled nitrate NO was added simultaneously with conservative tracers sulfur hexafluoride and 4 3 . I-131 into a wastewater in...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید