| Abstract |
Precise repetitive gravity observation were initiated in early 1978 at Cerro Prieto geothermal field, for the purpose of monitoring reservoir changes during production, most notably subsidence and mass removal. The 70 station network was repeated through early 1983, and was accompanied by repeated leveling. The data, reduced to observed gravity differences, indicated persistent subsidence which may be related to production, lack of reinjection, and only partial recharge, but tectonic uplift is also seen. Development of potential equations permitted separation of true elevations form measured values and gravity data. These indicated not only elevation variations but significant mass removal with incomplete recharge. |