CCTV News: Pay attention to the latest progress of China's 41st Antarctic scientific expedition. During the ocean inspection in the Amundsen Sea, the expedition team not only conducted routine investigations and research on the sea area, but also used long columnar piston gravity column samplers to perform gravity column sampling operations. The sampling operation has obtained the longest sedimentary core in the Amundsen Sea and Sea Mountain area in the Antarctic region of my country, which can be used to reveal the evolution of the Amundsen Sea paleo-ocean and paleoenvironment.

The long columnar piston gravity column sampler is a scientific research equipment that relies on gravity to sample seabed sediments. It mainly includes four parts: cutting head for drilling samples, casing for storing samples, heavy blocks and triggers. It is understood that the total length of this gravity column equipment is about 22 meters, and the sampling location is located in a canyon area of ​​the Amundsen Sea and Sea Mountain, with a water depth of more than 2,800 meters. From the assembly to the recycling of the equipment, sediment samples were successfully obtained after more than 20 hours. After the scientific expedition team returned to China, they will conduct physical, chemical, micro-paleobiology analysis on the samples to understand the earth's environment at that time and provide a basis for predicting future climate changes.

Sampling of gravity columns: "Give the Earth"

Sampling of gravity columns in Amundsen Sea. The team members have a very vivid statement about this operation, called "Give the Earth". Although it is an "injection", it is actually a heavy-duty project. It took more than 20 hours from assembly, decentralization to recycling.

In early February, at 74 degrees south latitude and 110 degrees west longitude, it was rare to have a sunny day on the Amundsen Sea. Because the length of the gravity column used this time is more than 20 meters, the operation has high requirements for stability, so on the eve of the official operation, the "Xuelong 2" stopped the ship for on-site assembly of the equipment.

Xia Yinyue, director of the laboratory "Snow Dragon 2", introduced that the gravity column is divided into four sections, each section is 5.5 meters. Now see the two black tubes are its main tubes, connected by yellow joints. These plastic pipes are inner tubes, and the core samples are stored inside the inner tube. Each layer of outer tube is fitted with an inner tube, and the entire inner tube forms a whole. The sample taken out is a complete sample.

It sounds simple to connect the inner and outer tubes, but it is really not easy to operate. The outer pipe of more than 5 meters long is 206 kilograms, and each connecting head weighs 60 kilograms. After the inner pipe is connected, it must be completely driven by manpower for assembly. In order to fix, each inner and outer tube and connecting head have 8 corresponding screw ports, which makes the connection a delicate technical job. Xu Hao has participated in the gravity column operation in previous years, and he will coordinate the specific work of assembly and collection.

At 2 a.m., "Snow Dragon 2" arrived at the predetermined location for the gravity column operation. From the sea surface to the seabed more than 2,800 meters. If you want to "inject" the earth, how can you ensure that you don't misstep? The power positioning system was activated on board. Zhu Pengtao, the first mate of "Xuelong 2", introduced that gravity column operation requires relatively high position accuracy of ships (ships). The current sea conditions are relatively good, and the positioning accuracy error is about 10 cm.

Snow began to fall outdoors, and at 3:30 in the morning, the gravity column operation officially began. The gravity column is placed on the support frame and moves from the inside of the ship's side to the outside of the ship's side through the flip mechanism and the 6-ton crane at the stern. The most important thing is to coordinate the same pace and precisely.

According to the operation process, first use the geological cable to lower the gravity column to a position 9 meters away from the seabed at a stable speed. At this time, the yellow small heavy hammer hit the bottom first, stimulate the release switch and decouple, the gravity column falls freely, and relies on its own gravity to penetrate into the seabed for geological sampling. As the yellow heavy hammers into the water, the gravity column is adjusted to the correct position bit by bit. At 6 a.m., the gravity column began to lower the work. After 3 hours of drop-down recovery, the gravity column was discharged at 9:10 am. Xia Yinyue said that the depth of the re-up column should be about 2821 meters, the actual length should be more than 2840 meters, and the time to collect is about 2840 meters, and the tension begins to increase, reaching a maximum of 11.7 tons, and the normal tension should be about 7.4 tons. The high tension indicates that the gravity column is penetrated deep, and the effectiveness of sampling will be greatly improved. When the columns were placed on the deck, the yellow substance attached to the outer tube at the bottom section attracted everyone's attention.

According to Xia Yinyue, benthic sediments are relatively meaningful sediment rock strata. Samples taken for the first time in Amundsen Sea and Sea Mountain. He was very satisfied and the whole process went smoothly.

According to preliminary analysis, this gravity column operation successfully obtained samples of seabed sediment, which can be said to have successfully "give an injection" to the earth. As the scientific expedition team members return to China in-depth analysis and research, it will promote our country to further understand and protect Antarctica.