In the eastern comer of Kyrgyzstan, where the northern and southern ridges of the Tien Shan converge, lies a wonderland covered with glacier. Here, among the 20 peaks that rise above 6000 meters, and sandwiched between the South and the North Inylchek Glaciers, is the mysterious Mertzbaher lake. Every year, and sometimes twice a year, the lake suddenly empties, only to refill again with the melted glaciers that surround.
What is even more unusual is that only part of the lake drains. For the six kilometers long and one kilometer wide Mertzbaher lake is divided into two by a bridge of ice. While main lower lake empties regularly, the North-Eastern part of the lake, which is just half its size, is always full of water.
It was the German geographer and mountaineer Gotfrid Mertzbaher whom first discovered the lake in 1903 while leading an expedition to the central Tien Shan. When the group set off in 1902, their aim was to reach the 6995 meter summit of Khan Tengri. Initially, Mertzbaher attempted a route through the Byankol Pass and along the Semenov and Mushketov Glaciers, but insurmountable ice-covered rock forced the group back.
A subsequent approach via the Inylchek Glaciers, Mertzbaher and his colleagues were able to reach the hills of Khan Tengri. Although the expedition failed to reach the peak, it was at least confirmed that Khan Tengri was not located in the center of the Tien Shan knot, as an earlier expedition had suggested. It was, in fact, the highest point of prominent ridge that ran east of the knot, nor known as the Khan Tengri ridge.
It was here, close to where the Khan Tengri ridge terminates abruptly as its western end, that Mertzbaher made his real discovery. Trapped between the North and South Inylchek Glaciers, he came across a clear lake, now named after him, with its surface studded with floating icebergs. What made the lake so unusual, was that it suddenly drained, while the expedition was still working in its vicinity.
Twenty-eight years later, another group of explorers witnessed the same event. To their astonishment, Mertzbaher lake emptied before their very eyes, leaving great blocks of ice stranded on the exposed bed of lake. They recorded the events in graphic details: "The end of Inylchek Glacier was somewhat extraordinary with water spring up in different locations making terrible noises. Some of them ran down the Glacier slopes, while other gushed forth from deep cracks in the Glacier surface. Our horses were so frightened by the great roar and Glacier pulsation that we hardly managed to get them down the slope. There was a moment when the Glacier seemed to be at the point of breaking away and rushing downward destroying everything in its way!"
Some of the expedition group returned the following year in a renewed assault on Khan Tengri. To their amazement, Mertzbaher lake was full of water, and a myriad of small icebergs floated on its silent surface.
Hhe process whereby a glacier lake suddenly drains its water is called Jokulhlaup, or glacier burst. It has been reported that several lakes around the world have this specialty, says Professor Andrew Russell of Keele University, a specialist in this field. In the early days of the century, Graenalon, a lake impounded between a rock wall and one of the major outlet glaciers of Vatnajokull in Iceland, used to drain subglacially every four year, but later drained more frequently. In Switzerland, the Marjelen See glacier lake was reported to have drained 19 times among 1813 and 1900.
"It's unusual and spectacular to see, " says Russell who has recently returned from trip to Greenland where he has been studying glacier lakes. "While there has been a lot written about the subject, it is still very rare to actually see it draining." Rusell goes on to say that there is no universal theory to explain why they drain. "Linking a particular theory to a particular type of lake cannot be done. It depends on so many things like the configuration of the ice and the depth of ice to water. "
There are several theories to explain the regular outflow of water from Mertzbaher. Some scientist suggests that when the depth of water in the lake reaches a critical level, that portion of the South Inylchek Glacier that damns the lake begins to float. Once this happens, water from the lake empties rapidly under the glacier, spurting to the surface via crevasses that extend to the glacier bed. A second possibility is that pressure exerted by the water of the lake on South Inylchek Glacier becomes sufficient, once the lake reaches a certain depth, to cause deformation of the Glacier. If this deformation causes gaps to develop between the Glacier and its bed, the lake will drain.
The expeditions done to the borders of the Ice-covered lake was not enough to find an answer to the outburst, but only increasing the hypothesis.
A canyon-like feature in the South Inylchek Galcier, known as The Crack, may also play a part in the drainage of the lake. If the Crack fills up with water, the water drains away via tunnels in and under the glacier. These tunnels may enlarge to such an extent that a suction effect is caused on the smaller tunnels between the Crack and the lake, producing an increased flow of water from Mertzbaher lake. An increase in flow would accelerate the melting of the glacial ice surrounding the tunnels, thereby enlarging them and further allowing the lake to empty rapidly.
Unfortunately, none of these theories are entirely convincing and much more research is need to determine which, if any, is correct. Meanwhile, more recent observations have established that Mertzbaher sometimes empties twice a year - once in summer and once in winter. We need to wait to see whether the mystery surrounding the vanishing Mertzbaher will ever be explained.
Behind the icy edge
The international research expedition to the Mertzbaher high mountain lake is over. The Kyrgyz speleologists, together with French colleagues removed some secrecy from this lake, which was discovered exactly a hundred years ago by a German traveler.
Mertzbaher Lake is an unsolved phenomenon of the Central Tjen Shan. The lake lies between two large glaciers - Northern and Southern Enilchek, and is surrounded by impassible shores.
Eleven months a year this is an enchanting and beautiful lake, on the surface of which… emerald-blue icebergs dreamily drift! But at the end of each summer the lake wakes up. Huge icy slabs start coming to its surface. The cracking sound of broken ice is usually replaced with the underground boom… Water starts coursing down along the internal cavities of glaciers, causing significant vibration of the glaciers themselves.
Having passed more than 14 kilometres in the underground arteries, the water rushes into the estuary of the Enilchek River at a rate of 2,000 cubic metres per second!
No expedition has managed to explain the phenomenon of Mertzbaher Lake. The Kyrgyz speleologists form the Cave Preservation and Research Fund, together with scientists from abroad and the International Asian Mountains Trekking Centre decided to solve the secret. They have developed a global Enilchek-2004 research project. The first stage of the project was a research expedition, which was at the lake at the time when the water poured away.
Our extreme sportsmen, Alyona Dudashvili and Stanislav Kvitkovskij (they are known to our readers from Raid Gauloises reports - they represented our team) together with the French speleologist, Francos Villa and cameraman, Guillaume Maidachevsky, carried out the first research on the glacier and shot a video.
Chairman of the Cave Preservation and Research Fund, veteran of domestic speleology, Sergey Dudashvili, told us the details of the expedition.
- The expedition lasted for ten days only. What did you manage to do during this time?
- For the main stage of the expedition to be a success, it is necessary to have professional equipment. Alyona and Stas found a safe place for the base camp, developed several variants of transporting scientists to the surface of the glacier, observed its cavities and researched its temperature. The video was a kind of a small amusement for this working expedition.
- Do you have any suggestions as to how discharge of the lake water takes place?
- Scientists offer various hypotheses. The majority of them believe that the thaw water from the glacier gradually overfills the lake. At a definite moment the pushing force of water becomes powerful enough to raise ice slabs covering the entrances to underground caves to the surface. When the discharge of water is over, the slabs return to their former place and again freeze to the bottom. Bit this is a hypothesis and we shall have to find out how the unique natural mechanism actually works.
- How dangerous is the next trip to the lake?
- This is really an extreme project! Sportsmen will have to get to the secret highways inside the glacier through the crevices leading to the surface of Enilchek. Descending to the vertical caves is much more complicated than moving along horizontal tunnels. Besides, the glacier is an unsteady layer and it is in constant movement.
- How do you justify such a risk?
- If the project is successful it will be a sensation! Hydrology and glacier’s structural study is dangerous of course, but scientific discoveries are worth that. Besides, conquering a glacier system in watery conditions is equal to a world record. The whole expedition will be filmed by journalists from German and French channels, which will be subsequently turned into several full-length documentary films.
- I believe this project is expensive.
- Sure, it is. Its implementation requires 150,000 dollars.
- Where are you going to get it?
- Not in Kyrgyzstan, of course. Here there are many scientific funds and organizations, taking an interest in financing such projects. Besides, we have a preliminary agreement with the Central Asian Institute for Applied Research of the Earth.
- And if, due to lack of funds, the Mertzbaher secret remains unrevealed?
- You know, scientists and sportsmen of poor countries have a unique ability to implement great projects with the help of miserly resources. We shall manage it!
- A glacier does not like mistakes. The whole event needs the participation of professionals. Who of our fellow countrymen will run the risk?
- Veterans of domestic speleology will be accompanied by graduates of the school organized by our fund. The researcher of the underground world, Vasiliy Filipenko, selected 20 graduates from the capital’s higher educational institutions and is now training them. Last year we organized a trip for young people to the rayon of the Ferghana Range. The guys opened and researched several large caves there.
- What will the success of Enilchek 2004 mean for our country?
- At last Kyrgyzstan is entering the world multi-sports arena. Conquering this difficult glacier is another chance for our extreme sportsmen. A successful ending will attract the attention of foreign travelers and scientists for a promising sphere of Kyrgyz tourism - speleology.
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