Discovery of active hydrothermal venting in Lake Taupo, New Zealand
Introduction
Known occurrences of hydrothermal activity in deep (>30 m) freshwater lakes are few, and even fewer have been studied in detail. Even scarcer are examples of associated biological communities and include Crater Lake, Oregon (Dymond et al., 1989), Yellowstone Lake, Yellowstone National Park, Wyoming (Remsen et al., 1990), Lake Baikal, Siberia (Crane et al., 1991) and Lake Tanganyika, East Africa (Tiercelin et al., 1993). Direct observation of active venting has been seen in Yellowstone Lake by using a remotely operated vehicle, and in Lake Tanganyika by scuba divers. Here we report the results of the joint New Zealand/German Taupo ’98 dive project with the submersible Jago which includes the first observations of vigorous hydrothermal venting in a lake using a manned submersible.
The aims of the project were to: groundtruth geophysical anomalies in an area near the Horomatangi Reefs of Lake Taupo that indicated probable hydrothermal activity; sample and analyze vent fluids and any mineralized samples; provide insight into the spatial, temporal, and chemical evolution of the hydrothermal system; and determine the nature of any biological activity associated with venting.
Section snippets
Regional geologic setting
Lake Taupo is New Zealand’s largest lake covering 623 km2 and is the site of one of the world’s most active rhyolitic calderas as part of the Taupo Volcanic Zone (TVZ; Wilson, 1993; Fig. 1A). Taupo is the oldest currently active rhyolite center in the TVZ, having been active for >330 ka (Wilson et al., 1984). Lake Taupo is thus the focus of some of New Zealand’s largest rhyolitic eruptions, including the 26.5 ka Oruanui eruption that generated 430 km3 of fall deposits and 300 km3 of pyroclastic
Water chemistry
The relatively high concentrations of dissolved salts in several lakes found in the TVZ have been attributed to an input from hydrothermal fluids (McColl, 1972, McColl, 1975, White et al., 1980, Schouten, 1983, Timperley and Vigor-Brown, 1986). For example, mass budget calculations for Lake Taupo waters show a substantial excess (∼2.4 times) of dissolved salts flowing out of the lake relative to those flowing in with surface water, including input from thermal springs on the northeastern and
Discussion
The Horomatangi geothermal system is a rare example of an active geothermal system in the TVZ that is directly associated with an individual volcanic feature, i.e. the main source vent area for the 1.8 ka Taupo eruption. The size of the Taupo eruption meant that caldera collapse will have occurred (Wilson, 1993), infilling the lake with large quantities of volcaniclastic rocks (Davy and Caldwell, 1998). Thus any hydrothermal activity affecting these rocks is post-1.8 ka which makes the
Acknowledgements
This research project was done in partnership with the Tuwharetoa Maori Trust Board and we thank them for their permission to dive on the Horomatangi Reefs site. We acknowledge the skill and enthusiasm of Jago pilot Jürgen Schauer and dive coordinator Karen Hissmann. We are grateful to Chris Jolly, Les Porter, Steve Mawdsley, Gareth Davies and John Baker in providing the necessary logistical support. Comments made on an earlier draft by G.J. Massoth and reviews by R.W. Collier and M.H.
References (55)
- et al.
Geophysical evidence on the structure of the Taupo Volcanic Zone and its hydrothermal circulation
J. Volcanol. Geotherm. Res
(1995) Geochemistry of fluids associated with the 1995–1996 eruption of Mt. Ruapehu, New Zealand: signatures and processes in the magmatic-hydrothermal system
J. Volcanol. Geotherm. Res
(2000)Hydrothermal hydrocarbon gases: 1, Genesis and geothermometry
Appl. Geochem
(1998)- et al.
Gravity, magnetic and seismic surveys of the caldera complex, Lake Taupo, North Island, New Zealand
J. Volcanol. Geotherm. Res
(1998) Geothermal gas equilibria
Geochim. Cosmochim. Acta
(1980)Geothermal solute equilibria. Derivation of Na-K-Mg-Ca geoindicators
Geochim. Cosmochim. Acta
(1988)Relative importance of thermodynamic and kinetic processes in governing the chemical and isotopic composition of carbon-gases in high-heat flow sedimentary basins
Geochim. Cosmochim. Acta
(1997)- et al.
Carbon and hydrogen isotopic compositions of New Zealand geothermal gases
Geochim. Cosmochim. Acta
(1984) - et al.
Sponge ‘sentinel’ of heavy metals
Sci. Total Environ
(1985) - et al.
Weathering of pumice in the sediments as a possible source of major ions for the waters of Lake Taupo, New Zealand
Chem. Geol
(1985)
Heat flow measurements in the sediments of Lake Taupo, New Zealand
Tectonophysics
The 26.5 ka Oruanui eruption, New Zealand: an introduction and overview
J. Volcanol. Geotherm. Res
Mercury and other heavy metals in trout of central North Island, New Zealand
N. Z. J. Mar. Freshw. Res
Ohaaki reservoir chemistry: Characteristics of an arc-type hydrothermal system in the Taupo Volcanic Zone, New Zealand
J. Volcanol. Geotherm. Res
Hydrothermal vents in Lake Baikal
Nature
Geodetic measurement of deformation in the Taupo Volcanic Zone, New Zealand: the north Taupo network revisited
N. Z. J. Geol. Geophys
Bacterial mats from Crater Lake, Oregon and their relationship to possible deep-lake hydrothermal venting
Nature
Copper and zinc toxicity in Ephydatia fluviatilis (Porifera: Spongillidae)
Trans. Am. Microsc. Soc
Freshwater sponges from Australia and New Zealand
Rec. Aust. Mus
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