Glacial Lakes Amongst Southern Alps of New Zealand44.8S 169.2E
Glacial lakes can be seen here, nestled amidst the peaks of New Zealand’s Southern Alps. Scientists have found that hundreds of steep mountain glaciers, which rapidly pass their ice gains down to their termini, have all fluctuated in size due to climate change over the last 35 years. Between 1976 and 2005 the volume decreased more than 10%, from 54.60 km3 to 48.74 km3. More than 92% of this loss was from 12 of the largest glaciers.
For the big glaciers, glacial lakes have begun to form at their fronts as lowering ice levels reach the level of their outlet rivers. Once a lake has formed, it eats at the glacier far faster than surface melt. At the front of the glacier, the ice cliff calves bergs into the lake. This positive feedback ensures a massive and catastrophic depletion of the glacier volume, creating an irreversible tipping-point for the glacier. It would take an ice age climate to drive the glacier back across the lake and to reverse the process (click here for more information).