Seven unsolved mysteries in Antarctica: hot water lake and flying saucer

Antarctica, also known as "the Seventh Continent", is located at the southernmost end of the earth. Its land is almost within the Antarctic Circle, surrounded by the Pacific Ocean, the Indian Ocean and the Atlantic Ocean. It is the continent with the highest geographic latitude in the world, and also the continent with the most longitude crossing. Its total area is about 14 million square kilometers, accounting for 9.4% of the total land area of the world. With an average altitude of 2350 meters, it is the highest continent in the world.
Because Antarctica is too remote, and because of its unique geographical location and environment, ordinary people don't know it very well, so the mysterious events happened in Antarctica are rarely known by people. The next few things to be said are the famous unsolved mysteries in Antarctica, which can't be explained up to now!

1. Mystery of hot water lake:
   Hot water lake is located in the "oasis" of the Antarctic ice sheet (2% of the land covered with ice and snow for a very long time in the guide). There is a layer of clear and bright fresh water on the lake surface. The temperature under the fresh water is as high as 27 ℃, 47 ℃ higher than the average temperature of the surface ice. Scientists have found that there are neither active volcanoes nor hot springs at the bottom of the lake. Moreover, the temperature of the sediment at the bottom of the lake is lower than that of the water layer at the bottom of the lake. Therefore, it can be concluded that the heat source is not from the underground.
   
2. The mystery of Flying Saucers:
   There is no doubt that Antarctica is the most frequent place for flying saucers to appear on the earth. Many flying saucer sightings have been recorded in the scientific research bases set up in Antarctica around the world.
   
3. The mystery of freshwater lake:
   Scientists in Britain and Russia have announced the discovery of a freshwater lake in Antarctica the size of Lake Anluo, which has existed for one million years. NASA experts say it's incomprehensible and against the laws of nature that such a large area of freshwater lake exists in the ice dripping Antarctica.
   
4. The mystery of ozone hole:
   In the late 1980s, scientists found that there was a big hole in the ozone layer over Antarctica, which was the "ozone hole". It has been thought that the reduction of the ozone layer is the result of industrial pollution and human neglect of environmental protection. However, with five million square kilometers of Antarctica's continent inaccessible, it's hard to understand why it's polluted.
   
5. Mystery of animal ice sculpture:
   Explorers have found that on the other side of Antarctica, near the Indian Ocean, there are many giant ice sculptures, dolphins, sea lions and many other animal shapes. These animals are lifelike in shape, and their eyelashes and claws are also clear and distinguishable. The tall ones are more than 50 meters, and the short ones are more than 20 meters.
   
6. The mystery of time gap:
   Recently, American physicists found that there are some swirling gray white smoke over Antarctica. At first, they thought these were just ordinary sandstorms. But the gray smoke did not change shape or move with time. The researchers decided to study the phenomenon carefully. They launched a weather balloon equipped with instruments for measuring wind speed, temperature and atmospheric humidity. However, as soon as it was launched, the balloon soared and soon disappeared.
   After a while, the researchers retrieved the balloon with a rope tied to it. However, to their surprise, the balloon's timer showed the time on January 27, 1965, exactly 30 years ahead of schedule! After confirming that the instrument on the balloon was not damaged, the researchers carried out several more similar tests. But every time it shows that the time is backward, the timer shows the past time. This phenomenon is called "the gate of time". The researchers reported to the White House. Now, research on these unusual phenomena is still in progress. It has been speculated that the spinning space over Antarctica is a gateway to other times.
   
7. The mystery of the once lost Antarctic ice sheet:
   Recent evidence suggests that the western Antarctic ice shield has disappeared at least once in the past 1.3 million years. The temperature won't be higher then today. This is a challenge to the traditional concept of ice shield structure erecting.