Researchers at the GNS Institute of Science in New Zealand have unveiled complex maps that reveal a hidden hydrothermal system beneath Lake Rotorua, which lies within the ancient crater of an extinct volcano on the North Island.
The lake is famous for its rich Maori history and has witnessed a legendary love story, in which a chief’s daughter defied a taboo to be with her beloved warrior, adding cultural importance to the area.
According to the Live Science website, the detailed maps, which cover about 68% of the lake floor, were produced through a collaborative effort involving GNS Science and the Royal New Zealand Navy, using advanced technology such as multi-beam echo sounders and magnetic surveys. The team identified volcanic craters, an ancient river, and a large magnetic anomaly in the southern region of the lake.
Cornel de Ronde, a principal scientist at GNS Science, admired the revelation that the glasses were being worn for the first time, emphasizing the newfound clarity that these maps bring to the lake’s submerged terrain.
The negative maps also revealed magnetic anomalies, a rare event attributed to hydrothermal fluids altering volcanic rocks, turning magnetite into pyrite, known as fool’s gold.
The results indicate that hydrothermal systems, previously thought to be limited to the mainland, extend into the depths of the lake. Heat flow maps revealed rising temperatures near the bottom of the lake, indicating hot water rising from below. Eruption craters also demonstrate the presence of hydrothermal activity in the same area, such as a magnetic anomaly.
Despite this dynamic geological activity, the lake floor maintains a relatively cool temperature of about 57°F (14°C).
De Rond explained that the huge size of the lake facilitates temperature regulation, counteracting the heat emanating from below. Although imperceptible to swimmers, the delicate devices detected slight fluctuations in temperature over the course of a month.
The site concluded by saying that this fascinating exploration beneath Lake Rotorua not only adds a new dimension to our understanding of hydrothermal systems, but also emphasizes the delicate balance that allows this geological landscape to coexist with the daily life of the lake.
The scientific community is eagerly awaiting further insights into the implications of this discovery for our understanding of underwater volcanic landscapes.
