Acid lake atop real-life 'Mount Doom' captured in striking new image from space station - Livescience.com

An astronaut aboard the International Space Station (ISS) has snapped a stunning image of a snow-circled hydrothermal lake atop the real-life "Mount Doom" in New Zealand.

The hydrothermal lake at the summit of Mount Ruapehu, known as Crater Lake, or Te Wai ā-moe, sits between the mountain's three main peaks, the tallest of which reaches 9,177 feet (2,797 meters) above sea level.

A magma chamber deep within the volcano heats the lake, and as a result, the temperature of the lake fluctuates between 59 and 113 degrees Fahrenheit (15 and 45 degrees Celsius).

The lake is also highly acidic, with a pH of less than 1, due to large amounts of volcanic gases that dissolve in the water, according to the Earth Observatory.

The hydrothermal lake is the only accessible part of the volcanic system that researchers can study, and rapid temperature fluctuations in the water can reflect changes in the activity below the volcano's snowy peak. .

In June, the alert level for Mount Ruapehu was increased from "minor volcanic unrest" to "moderate to heightened volcanic unrest," according to the geological hazard information website GeoNet (opens in new tab), following a mini-swarm of earthquakes under the volcano.

During this time, the temperature of the water in Crater Lake sharply increased to a peak temperature of 104 F (40 C). .

But the alert level was downgraded in July after the water temperature dropped to 75 F (24 C).

Based on the temperature changes in the lake, experts believe the spike in activity was the result of a brief magma intrusion in the chamber below the volcano, according to the Earth Observatory. .