| Title | Seismological and Self-Potential Surveys at InfernoCrater Lake, Waimangu Geothermal Field |
|---|---|
| Authors | Tosha T., Ishido T., Nishi Y., Matsushima N. and Scott B.J. |
| Year | 1996 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | |
| Abstract | A short term micro-seismic survey and self-potential (SP) measurements were performed in 1994 and 1996 around Inferno Crater Lake, Waimangu Geothermal Field, to increase our understanding of the hydrothermal dynamics associated with the water level change at the lake. Seismic survey with five seismometers around the lake revealed that the acoustic noises were concordant with rising water levels in Inferno Crater Lake and the overflow, being strongest during the period of oscillating water level and overflow. No significant seismic signatures were recorded during water level recessions. SP measurements were made along four survey lines in Waimangu Geothermal Field and repeat SP surveys were carried out eight times along the footpath in Waimangu Valley. Terrain-related potentials are dominant along the most survey lines though positive SP anomalies are observed near Inferno Crater Lake and Waimangu Geyser. Remarkable SP changes with time were also found among the repeat SP surveys near Waimangu Geyser, which is probably caused by the change of subsurface condition. |