How do I get deep seawater? How to dive in the deep sea

To analyze the chemical composition of seawater, it is necessary to obtain a sample of seawater. Surface seawater can be obtained with buckets and pumps, but seawater at depths of several kilometres is a matter of choice.

Scientists have specially designed special containers for this purpose. A plumb block is fixed at one end of the hanging cable on the boat, the water intake container is lowered to a predetermined depth, and then the lid of the container closes automatically when the winch turns.

In this case, the approximate depth can be estimated from the length of the cable being released. Of course, the exact water pressure and temperature are measured by a reverse mercury thermometer.

The water collector used from the beginning of the 20th century until the 70s was designed by the Norwegian oceanographer Nan Xian.

This water collector wraps a cable around a metal hammer and lowers it from the boat into the sea. When the metal hammer touches the switch of the water collector, the clamp spring of the water collector disengages and the thermometer is inverted, causing the valve of the water collector to close. At the same time, a metal hammer attached to this water collector falls, striking the switch of the next water collector.

In this way, the water collectors fixed to the cable move one after the other, taking the sea water at different depths. The design of this water collector is excellent, the failure rate is very low, and it was once widely used in the world. But because it is made of metal, the seawater collected is slightly polluted, and less seawater can be collected at a time, only 2 3 liters.

In its place was a water collector made of plastic designed by the American, Niskin. The water collector still uses a mechanical signal to control the action of the water collector, but the barrel of the container is not turned over, and the upper and lower lids are closed together. In this way, up to 30 litres of seawater can be collected at a time.

Recently, mechanical signals have also been gradually replaced by electrical signals, and the lid of the water collector will close as soon as an electrical signal is emitted from the operating ship.

When determining ultra-trace amounts of heavy metals and organics, Niskin water extractors can still lead to the formation of impurities. Other special water extractors are used in the analysis of these studies.

Scientists are still working on improving the water collector to prevent impurities from being generated during water extraction. If the cable holding the water collector is metal, impurities will inevitably occur due to rust. The world's first titanium cable was installed on the ship "Shiraho Maru" at the Institute of Oceanography of the University of Tokyo, and the analysis was carried out in a clean room.

Some scientists need large quantities of high-quality seawater samples. For example, scientists who study trace amounts of radioactive atoms or isotopes. Today's water collectors can take up to 270 litres of seawater at 2 different depths at once.

Obtaining the "right sample of seawater" is the first and most important step in the study of the chemical composition of seawater.

How can humans get seawater at different depths at once? An ingenious design to solve easily!

How can humans get seawater at different depths at once? An ingenious design to solve easily!

Deep-sea diving refers to scuba diving, which requires a compressed air bottle (not an oxygen cylinder as many people think) and uses an underwater breathing apparatus to breathe, which is a kind of diving that really goes underwater.

A full set of scuba diving equipment includes masks, snorkels, fins, respirators, diving instruments, tanks, buoyancy adjustment vests and wetsuits, etc., and divers will also carry necessary auxiliary equipment such as diving knives, underwater flashlights and even spearguns when diving in open water.

Carry an oxygen cylinder, wear a pressure-resistant suit, wear a webbed on your feet, and wear a waterproof lamp on your head!