Source: CCTV News Client
During this year's National Day, the mainland's deep-sea exploration technicians are conducting an all-round exploration of the seabed geology at a depth of 3,000 meters on the mainland. This is the first exploration mission carried out by the mainland so far using completely independently developed deep-sea exploration equipment. At present, the survey has entered the final stage.
CCTV reporter Wang Shiyu: The position on the second deck of the "Haiyang Shiyou 720" ship. Compared to the previous live broadcast, this deck is much more crowded. This layer is placed another important set of equipment of the "Sea Longitude" system, which is the location of the equipment that emits seismic waves underwater, and the high-pressure air gun is hung below.
CCTV reporter Wang Shiyu: The staff is preparing to release the high-pressure air gun into the water. Normally there would have been six rows of launchers, but now four rows are actually in the water. In another 10 minutes or so, these two rows will all be put down and start working, at that time, this place will belong to a high-pressure area, and no personnel can stay. So we also took advantage of this gap to be able to come here for a closer visit.
CCTV reporter Wang Shiyu: Every time a high-pressure gas cylinder emits a seismic wave signal, it will release a pressure of more than 130 standard atmospheres, which will be launched to the bottom of the sea through the air guns hanging in this row.
CCTV reporter Wang Shiyu: We filmed the air gun working in the sea before, and every time the signal is transmitted, bubbles will form. However, despite the pressure, the sound heard on the boat is actually very small, and the staff told us that this is precisely the characteristic of working in deep water, because the water is now deep enough that the sound has been gradually absorbed as it propagates to the bottom of the sea.
CCTV reporter Wang Shiyu: Under normal circumstances, these air guns will fire 4,000 to 6,000 seismic waves every day. Although they all look like "iron pimples", they are actually very accurate. Under normal circumstances, 40~50 air guns will be emitted at the same time, and the difference in this synchronization rate should be controlled within 1 millisecond, and the maximum can reach 0.05 milliseconds. That's why these devices need to be pulled back to the deck every once in a while for service and maintenance, checking their wear and tear to ensure they don't affect detection.
CCTV reporter Wang Shiyu: I would also like to explain to you in particular that although we are emitting seismic waves, they are actually very different from earthquakes in the real sense, and will not cause any changes in the structure of the seabed strata, but only the amount of energy used for detection.
CCTV reporter Wang Shiyu: Now that this exhaust gun has also been put into the water, it means that soon the air gun next to me will also complete the preparation before the survey, so it will enter the final stage of exploration.
(CCTV reporter Wang Yan, Zhang Wei, Zhang Hao, Zhang Congjing, Zhang Bo)