Puncture lake in Kirghizistan

Kirghizistan, in central Asia, fed by 7,000 meters of peaks, the Inylchek glacier contains an unexplained mystery for hundreds of years, it is unique in the world that every summer, lake Merzbacher there dried up in 3 days. Why?

These questions have been in place for exactly a century, when the German geologist Gottfried Merzbacher discovered the lake in 1904 (and since then it has been named after him). Wishing to break the mystery of Merzbacher Lake, an international expedition conducted by GFZ Berlin set out for the lake this summer. For the first time, scientists try to answer that question.

The giant glacier Inylchek is 65 km long, with two main branches converging 15 km from the river's end. At the intersection of the two branches, at 3,300 m altitude, it is Merzbacher Lake, 130 meters deep, partially covered by icebergs. Every year, the lake drains out in 3 days, around early August.

What could not have happened. At 16:00 on August 6, 2004, Merzbacher Lake began draining the water itself! Every year, this strange phenomenon happened again at this time. With its calm appearance, its price of water gradually poured into the depths of the Inylchek glacier. Less than 30 km and after a few hours, the immense valley was flooded. From a humble river on the mountain, Inylchek has become a ferocious ocean, occupying the entire space. For three days and nights, the lake cleared 250 million cubic meters of water, leaving only a huge carpet of sad ice in the lake. On August 9, the spill phenomenon was completed in the valley. The glacier ended its changing form. And Merzbacher lake is empty. Thanks to the miracle that the lake originating from this glacier can self-discharge water within 3 days? Where did the water flow? How has the water removed? And how does the lake fill with water again?

July 19, 2004. When it came to Bichkek, the capital of Kirghizistan, difficulties were revealed. Serguei Dushavili, one of the expedition's leaders, announced: " We may be forced to use horses for 4 days, if the helicopters are not available ." The Russians cannot be left behind, accounting for the majority of the team, even in Kirghizistan only one helicopter. But then a giant MI-8 also appeared to welcome us after two days of hard work on the bad road.

We set up two camps, 20 km apart: a camp at the foot of the glacier, where the Inylchek River originated and the second camp was located right on the river, opposite Merzbacher Lake. In daily radio communication with each other, we call the names of two camps, Paliana and Basa respectively. The glacier was divided into many areas, from west to east, and each crew was responsible for studying areas close to their camp. At that time, the lake was still full of water, because we had observed it in advance in the morning. Even very full of water, according to the pilots often flew here to drop climbers down the foot of the 7,000-meter-tall Khan Tengri mountain. In July, Merzbacher reached record levels of water flow.

Each person has their own hypothesis

The characteristics of each expedition are the luck that weighs heavily on the mysteries of nature. Our expedition did not escape that rule. We want quick answers after being at the scene for a few days. However, the expedition was programmed for 4 years. The goal of this first year is to establish a network of GPS points, to measure, thanks to satellites that locate all glaciers' movements. Dr. Wasili Michaljow, the expedition chief, predicts: " Maybe we will have more answers in the next few weeks. But now we should reduce hypotheses ." Even so, the hypotheses still stimulate people's curiosity. At that time, Serguei Dudashvili made his hypothesis:

There was not any hole that allowed Merzbacher Lake to drain the water, but many holes were blocked by giant ice blocks. In winter, these ice blocks still close to many porous bottom surfaces as a natural barrier. Thanks to that, the lake is flooded, because the "valve covers" are still closed due to the effect of low pressure and temperature. When summer comes, the water gets hotter and the big blocks of ice begin to melt, until - according to Serguei - they lose their adhesion, abruptly rise to the surface. This phenomenon corresponds to the sudden opening of the "valve covers". Such a hypothesis can only be sustained if the lake water level rises downstream as well. So we have to wait to know where the truth is.

July 28, 2004. 6 days have passed since we arrived at Paliana camp. We squared a region of about 10 km. Average altitude 3,000 meters. For safety reasons, our camp is located on the west side of the Inylchek River, which makes us forced to wade into the glacier. Water temperature is 1 degree C.

While we installed milestones on the end of the glacier, cave researcher Wasili Filipienko identified two giant caves. Less than 2 km away from the lake, these two caves may be within their hydrological network. During the "hot" period, melting and the flow of water freezing in the two caves, not to mention the lake threatening to crack at any time, did not allow scientists to probe them. After two attempts to penetrate the unsuccessful cave, we gave up. Cave research work must be left to fall.

August 1, 2004. As if unaware of the expedition of the expedition, Merzbacher Lake was still full of water. Serguei then suggested going south. Here the glacier is wider, about 4 km and especially disturbed. From our camp, it took 3 hours to walk to the secret land separating water from the lake, from the glacier in particular. We knew the lake was in this area, but no one was there. What happens in this natural barrier? How did the transition between water and ice factor take place?

The simple, and most likely explanation for the existence of the lake, is the rise of ice from the south branch of the glacier at this place. Instead of melting along the north branch in a perfect Y, like every glacier in the world, this branch rose to form an icy barrier that kept Merzbacher lake water.

We never reached the south bank of the lake. The closer they get, the bigger the glaciers, merging together and creating many cracks. We have one thing to be certain: this rising face of the male branch is the cause of the world's only punctured lake phenomenon. Without this abnormality there will be no lake. For a century, Merzbacher Lake moved from 2 to 3 km downstream. Since then the ice barrier is very close to the junction of the two rivers, and perhaps the lake will disappear in a fairly near future.

August 3, 2004. End of the temporary expedition. The lake is still full of water. I decided to stay alone until the lake was dry. It was not at Basa camp, where it was difficult to observe, but in the valley, about 30 kilometers below, where the phenomenon of water rising would be spectacular.

August 5, 2004. Tatiana shared with me many signs that the lake began to drain. New water points appear in the riverbed. Flow of Inylchek glaciers increases gradually .

August 6, 2004. At 16 o'clock. This time the river was 3, 4 times the mass. Water overflow valley. Surely the lake is falling apart. Serguei's hypothesis is removed. Water flow keeps increasing for 2 days. It is clear that the opening of the "valve covers" does not happen suddenly. Certainly the melting of the ice buttons gradually releases the water of Merzbacher lake, not the rise of the ice buttons.

Finally, to solve the mystery of the Merzbacher hole, maybe we have to wait a few more years .