| Title | Geyser activity at Geyser Flat, Te Puia, Rotorua: Insights from the second geyser monitoring deployment |
|---|---|
| Authors | B. Keats, B. Scott, M. Zuquim, R. Reeves, N. Macdonald |
| Year | 2025 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | geyser, temperature, surface features, geothermal monitoring |
| Abstract | The Rotorua Geothermal System (RGS) covers an area of ~15 km2, with about 1,500 geothermal surface features mapped to date. Geothermal features, including geysers, are a key driver for tourism in Rotorua, and hold significant cultural, economic, and environmental value. Thermal activity in the RGS was in severe decline from the 1960s through to the mid-1980s due to overexploitation. A state of the environment monitoring programme was instated in early 1980s to collect data on the state of the system. However, data on the state of the geysers was ad hoc and not suitable for quantifying the geyser’s state of health. A temperature sensor-based monitoring system was developed at Te Tohu and Pohutu geysers and Te Horu pool in 2022 to record temperature spikes from erupted fluids and translate this data into a record of eruptive activity that could be compared to historic periods. The trial was a success, and a second monitoring deployment was undertaken in 2024. This deployment redeployed redundant sensors from Te Tohu and Pohutu to the nearby Mahanga and Waikorohihi geysers, which had recently started erupting again, and added a submerged sensor at 3 m depth in Te Horu pool to investigate basal inflows. Analysis of data from these deployments confirmed the resumption of activity at Mahanga and Waikorohihi, after two decades of dormancy, and showed that recent geysering at Te Tohu and Pohutu geysers to be amongst the most active on record. The submerged sensor at Te Horu pool provided evidence of a connection to Pohutu-Te Tohu, and confirmed that Te Horu is an active feature in its own right. The geyser monitoring programme is now integrated to the State of Environment programme for Rotorua, ensuring regular data on the state of geysering activity here is available to inform the future management of the RGS. |