Water Resources Research Act Program

Details for Project ID 2004GA56B

Seismic imaging of fracture systems in crystalline rock

Institute: Georgia
Year Established: 2004 Start Date: 2004-03-01 End Date: 2005-02-28
Total Federal Funds: $16,000 Total Non-Federal Funds: $32,000

Principal Investigators: Leland Long

Project Summary: In areas like the Georgia Piedmont, that are underlain by fractured and unweathered crystalline rock, water resources are limited to surface reservoirs and shallow wells. Because surface reservoirs are approaching full development, and because new large surface reservoirs are difficult to site, the water needs of the expanding suburban and urban areas in central Georgia will have to come from alternate sources. These sources include conservation and ground water. In crystalline areas the near-surface ground water supplies, usually exploited by shallow wells, have a capacity that is limited by thin soils, but there exist fracture systems in the crystalline rocks that can supply significant amounts of water because they draw from a wide area and from many near-surface shallow aquifers. These fractures and their supply system offer a mechanism for efficient pumping of water for municipal water supplies. Fracture systems with production potential are difficult to locate and evaluate, and, hence, are underutilized. A growing need exists for methods to detect and characterize open productive fracture zones in the metamorphic and igneous rocks of the Georgia Piedmont. Some communities, for example Lawrenceville, have successfully tapped such fracture zones as a supplement to surface reservoirs. An increasing number of Counties and local governments are evaluating ground water in fractures as a primary or supplemental source to their existing surface water systems because in periods of drought, surface reservoirs and shallow wells will be depleted before deep fractures. A more important aspect of productive fracture zones is to understand the geometry of the productive fractures and their relation to near-surface water sources. A quick and non-intrusive method to locate and evaluate fracture zones that are productive could save on drilling exploration techniques and expand available water resources.