Abstract
The purpose of this study is to gain a better knowledge of superconducting gravimeter (SG) data at the Metsahovi Gravity Station in Southern Finland. The SG data are very precise (accuracy even 1 ngal) and very sensitive to various environmental and hydrogeological effects. Because of this we must isolate and analyze the characteristics of these effects before we are able to consider their effect on data. As a result of extensive studies we have isolated four hydrogeological sources influencing on the gravity field at the Metsahovi site. The first one, a time-varying amount of surface and soil water at and close to the Station causes an immediate effect to gravity after rains. The second source, a water flow in the fractures of crystalline bedrock above the groundwater table and below the Station can be observed soon after rains. The third one, the porosity variation of the ground in the depth range within which the groundwater level varies is a long-term effect. The variation rate of this effect is equal to the variation rate of groundwater level. The last source, a time-varying flow rate of groundwater in an inhomogeneous ground causes a detectable long term anomaly on gravity. The strength of these sources can vary in a large scale from zero to even several hundreds of ngals depending on a site.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
