Filters: Tags: ground-water flow (X)3 results (135ms)
The effect of terrace geology on ground-water movement and on the interaction of ground water and surface water on a mountainside near Mirror Lake, New Hampshire, USA
The west watershed of Mirror Lake in the White Mountains of New Hampshire contains several terraces that are at different altitudes and have different geologic compositions. The lowest terrace (FSE) has 5 m of sand overlying 9 m of till. The two next successively higher terraces (FS2 and FS1) consist entirely of sand and have maximum thicknesses of about 7 m. A fourth, and highest, terrace (FS3) lies in the north-west watershed directly adjacent to the west watershed. This highest terrace has 2 m of sand overlying 8 m of till. All terraces overlie fractured crystalline bedrock. Numerical models of hypothetical settings simulating ground-water flow in a mountainside indicated that the presence of a terrace can cause...
Rates of flow across the sediment-water interface (seepage), measured every 5 seconds with an automated seepage meter and summarized every minute with a digital datalogger, are presented for 17 measurement locations at Newtown Creek, NY. Final values are presented in cm/day. An electromagnetic seepage meter, custom made for USGS by Quantum Engineering, was capable of measuring seepage averaged each minute with an accuracy of +/- 0.5 cm/d. Deployments at each location lasted at least two tidal cycles. Three ESM systems were available but most of the time only two systems were operated simultaneously, requiring several weeks to obtain measurements at all 17 locations. Data are presented in an Excel workbook composed...
Evaluation of faults and their effect on ground-water flow southwest of Frenchman Flat, Nye and Clark Counties, Nevada: A Digital Database
Ground-water flow through the region south and west of Frenchman Flat, in the Ash Meadows subbasin of the Death Valley ground-water flow system, is controlled mostly by faults which arrange the distribution of permeable and impermeable rocks. In addition, most permeability is along fractures caused by faulting in carbonate rocks. Large faults are more likely to reach the potentiometric surface as deep as 325 meters below the ground surface and are more likely to effect the flow path than small faults. This study concentrated on identifying large faults, especially where they cut carbonate rocks. Small faults, however, may develop as much permeability as large faults if they are penetrative and are part of an anastomosing...