Geothermal scientist Ted Lloyd (right) measures the temperature of a boiling spring at Ōrākei Kōrako in October 1960, while assistant Leon Boielle takes notes.

Over a period of 30 years Ted Lloyd undertook detailed surveys of hot springs and geysers in the Taupō Volcanic Zone, producing detailed maps of the Ōrākei Kōrako, Waiotapu and Whakarewarewa geothermal areas. His records provided clear evidence of the decline of surface thermal activity due to geothermal exploitation. In the 1970s and 1980s he and Ron Keam worked to save the remaining hot springs and geysers from further damage.