In 2005, an ice shelf in northern ellesmere island broke, releasing a 66-square-kilometer "Iceland". Iceland moves to Beaufort Sea. Beaufort Sea is located in the northeast of Alaska, USA and north of the northwest of the Canadian Arctic Islands. This is an important oil exploitation area. The emergence of "Iceland" poses a threat to oil platforms. Fortunately, in August 2007, this big ice block entered a dead end of the island and stopped there. Scientists hope it will melt there forever-it may take decades. Ellesmere island lost another 200 square kilometers of ice, including one of the five Canadian Arctic ice shelves that completely broke and drifted to the Arctic Ocean. Also last summer, Peterman Glacier broke into a 29-square-kilometer "Iceland". Before this happened, Jason and his colleagues in the university were the first people to warn the world. This "Iceland" goes south along the niles Strait between Greenland and ellesmere island, posing a potential threat to ships and oil platforms at sea. Its drifting mileage has reached 2000 kilometers. At this time, it has lost about half of its mass, and its area has shrunk to 12 square kilometers, but it still poses a threat to passing ships in Canadian waters. What worries Jason and others is that the same glacier is now creating a new "Iceland", which is several times the size of Iceland in Peterman. The area of this huge new "Iceland" will reach 100 square kilometers.
In fact, at present, it seems that Peterman Glacier may break five "Iceland" next. On the satellite image, Jason marked five areas that are cracking on the ice with the letters A to E, in which 100 square kilometers of "Iceland" corresponds to film A, which is located at the forefront of the glacier and juxtaposed with film D with an area of 20 square kilometers. There are also b, c and e films behind.
However, before disconnecting Part A, it may be necessary to disconnect Part D first. "We think that if D goes, then E will go, and maybe B and A will go. D is the weakest link. Now only 3-4 kilometers are still connected, and A is 7-8 kilometers still connected. " Jason said July 15.
"The D film will leave soon." He continued, "If the weather keeps getting warmer, there will be strong winds and waves." Southern Weekend reporter asked him: "How likely are you to predict that D film will leave before we leave here in early August?" Jason touched his chest, his elbow and his knee and said, "I feel … I want to use my elbow, I want to use my knee …" He was not sure. He had predicted that Peterman Glacier would break between July 3rd and15th, but this prediction didn't come true.
Jason pondered for a while and said that in the next two weeks, the possibility of D-film being broken is greater than that of not being broken. "I think the chance is 60: 40. I think that by September, the possibility of fracture is 90%. " "I think glacier is a very interesting natural form. It has many puzzles and problems and is very complicated." 16 At 9: 30 in July, Allen sat on a bench on the deck in the sun, holding a can of beer. He has done a lot of work on the ice sheet in Greenland before, and this is the first time to study glaciers. "On one level, they are very direct and some kind of easy-to-understand phenomenon." He said, "The more snow accumulates, the greater the mass, and then it becomes this moving state, just like a conveyor belt. This is a very easy way to understand. "
"So when you reach these glaciers," Allen went on to say, "you will see their changes and greatness, their different melting ways, and their various reactions to different external factors. The problem you encounter is fundamentally a scientific problem, but it is also a daydream problem. "
Indeed, from the ship, Petermann Glacier is a white line, while from the satellite image, Petermann Glacier is a white belt. However, when you look at the glacier from a helicopter or set foot on it, its complex structure and ups and downs will immediately break the inherent impression that the glacier lacks individuality.
The surface of the glacier is not a ski resort or skating rink. Its surface undulates like an artificial hill in the park. It takes a little effort to walk. The difference is that the "ridge" of glaciers is often sharper, almost only enough for one person to walk on it.
Between these ups and downs, there are small puddles of different sizes and very irregular shapes. These small puddles are light blue, and there are often black substances at the bottom. Next to the puddle, you can often see cylindrical puddles with a diameter of 30 to 40 cm. These puddles are usually half a meter deep, but some are relatively shallow. It is also possible to see that the ice surface has just started to burst radially, which is a precursor to the formation of puddles. Black matter is also deposited at the bottom of the puddle. Like the black substance in the puddle, these clay-like substances are a mixture, which contains dust from the rock walls on both sides, products of human combustion brought by the atmosphere, and meteorite materials falling into the earth from space.
Overlooking the ice from a helicopter may be an unpleasant thing for people who are afraid of dense objects. Because from a height, the puddles on the ice are so dense that they almost catch up with the fish scales.
There may be a stream connection between puddles. Walking by the stream, you can only hear three kinds of sounds: the wind, the sound of running water and the footsteps on the ice. But the ice is actually very strong, and the feet will not sink when walking, leaving only shallow shoe prints. At the front of Peterman, the thickness of ice exceeds 10 meter, and scientists often park helicopters at work. In fact, there are dangers here. Streams sometimes flow under the "ice bridge". The "ice bridge" looks thick, but it is actually made of snow. If you step on it carelessly, most of your body will sink. Fortunately, it is not too difficult to distinguish between snow and ice. Although they are all white, the snow looks darker and a little yellow. In addition, polar bears pose a threat to people walking on the ice. Eric Philips, an Australian explorer on board, found seals dismembered by polar bears on the ice.
In some places, streams flow in deeper cracks, which are cracks in glaciers. Standing on the glacier, it is difficult to tell how many kilometers this crack is, because you will see it extending to the end of the field of vision. Running water makes it easier for cracks to expand, because on glaciers, melted water is like knives and drills.
Petermann Glacier flows from land to sea, and the initial contact position between the bottom of the glacier and seawater is called "grounding line". Petermann Glacier extends 70 kilometers from the grounding line to the front edge, and its thickness gradually decreases from the initial 600 meters to more than ten meters. In other words, this 70-kilometer-long ice surface floats on the sea surface, forming the so-called ice shelf.