Evaluation of spontaneous potential for monitoring groundwater movement in karst terrain

Spontaneous potential (SP) is a geophysical method that measures naturally occurring voltage in the earth. Negative anomalies arise from electrokinetic, or streaming potential, effects resulting from the flow of groundwater. In this study SP was monitored at sites in karst terrain in Virginia. The results were evaluated for effectiveness in detecting groundwater flow paths and rates. The ability of SP to distinguish between diffuse flow and conduit flow was examined. Soil temperature, soil moisture, and precipitation are major variables influencing SP data. An automated data collection system was devised and used for long term monitoring of SP changes and environmental variables and for measuring SP changes induced by artificial recharge of water into a sinkhole. Results were evaluated by comparison with geological observations, electrical resistivity, stream flow measurements, and speleological surveys. SP can effectively locate and track shallow groundwater flow paths in karst terrain. A relationship was observed between SP and changes in flow rate where the flow was through porous material, but SP could not be directly related to flow through solutional conduits. However, conduits may be indicated by SP anomalies where soil moisture is drawn into fractures that supply water to conduits. The influence of geologic structure must be considered in, interpreting SP results in karst. Refinement of the SP technique is promising for applications to environmental and geotechnical problems.

Name thesis:degree_name

M.S.

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geography

Department dc:contributor.department

Geography

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1986

Author dc:creator

• Slifer, Dennis

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/101321

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/101321