Details of the Abstract
| Title of paper | Controlled source electromagnetic monitoring of Inferno Crater Lake, Waimangu, New Zealand. |
| List of authors | Caldwell, T.G., Ogawa, Y., Ishizu, K., Kitaoka, N., Kirkby, A., Minami, T. |
| Affiliation(s) | GNS Science, Tokyo Institute of Technology, University of Hyogo, Tokyo Institute of Technology, GNS Science, Kobe University |
| Summary | Details of the experimental design and signal recovery methodology used to test the feasibility of CSEM measurements for the detection electrical conductivity changes using the cyclic behaviour Inferno Crater Lake at the Waimangu geothermal field as a natural signal source are described. A least-squares, time-domain approach was used for signal recovery at both the transmitter and receivers. This approach allowed hourly estimates of the amplitude and phase of the frequency-comb used for the transmitter signal to be recovered and allowed near-real-time remote monitoring of the transmitter. A key determinant of the success of the experiment will be whether it is possible to distinguish effects associated with the lake level change from changes in the 2-phase hydrothermal system beneath the lake. The receiver magnitude and phase variations observed strongly correlate with lake level but have different frequency dependencies. This observation is inconsistent with a purely galvanic (or static) effect caused by changes in lake level alone. |
| Session Keyword | 1.0 Instrumentation, data acquisition and processing |
| File upload |
1.0_controlled_source_electro_caldwell_02.pdf
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