| Title | Assessment of Total Heat and Mass Transfer of a Large Hot Pool Using the Balance Method (Ohaaki Pool, Broadlands-Ohaaki Geothermal Field, NZ) |
|---|---|
| Authors | Hochstein, M.P. and Henrys. S., |
| Year | 1988 |
| Conference | Japan International Geothermal Symposium |
| Keywords | |
| Abstract | Hot pools and hot lakes with minor discharge of chloride water can often be found over large hot water systems. These pools are fed by deep thermal fluids which usually have been mixed with less mineralised shallow water and which ascend along deep reaching fracture zones. In most cases these pools and lakes occupy an older hydrothermal eruption crater. The water in the pool is clear and deposition of silica occurs at the margin often forming overhanging deposits. In New Zealand the Ohaaki Pool (Broadlands-OhaakD, the Champagne Pool (Waiotapu), and the Waimangu Hot Lakes (Waimangu) are examples of such pools and lakes. Evaporative heat losses are high because of the high surface temperature but natural overflow is usually small. The concentration of chemical constituents of the hot water is almost constant over long periods indicating that the total upflow is significantly greater than the total mass flow given by evaporation and natural overflow. In this paper the likely total heat and mass transfer of the Ohaaki Pool in the Broadlands-Ohaaki geothermal field will be assessed; for locality of pool and wells cited refer to Browne (1986) and Henrys (1986). |