| Abstract |
Microgravity surveys together with the GPS data are normally used as a base of information to monitor land elevation and gravity changes caused by seismicity, volcanism and exploitation of geothermal fields. Precision gravity measurements have been conducted to monitor changes in fluid mass within a geothermal reservoir related to production, reinjection or phase changes. In Kenya, repeat microgravity surveys have been performed only in Olkaria geothermal field which is a producing geothermal field. Most geothermal fields in Kenya are magmatic in nature and magma movement is not only indicated by occurrence of seismic events but must also be supported by other data sets from microgravity and DGPS analysis. Consequently, GDC has put in place monitoring system that includes microgravity and differential GPS measurement. The goal of this paper is to showcase the data collected and the technique used for analysis to set baseline information for deformation monitoring of Paka geothermal prospect, which is one of the geothermal projects earmarked for development by Geothermal Development Company Limited. Data collected will be used for as a basis for future monitoring of geothermal systems. The outcome of this survey are computed gravity difference values between designated benchmarks that will be used as baseline data for future regular repeat investigations to monitor positive or negative changes from which information on surface deformations related to Paka volcano can be inferred. |