10,000 meters deep sea water is still liquid water naturally, but there are also some special states of water. It can be said that the material state is between liquid and gaseous state, that is, supercritical state of water, the temperature can reach more than 400 degrees Celsius.

Deep-sea pressure is very high, but because of the stable nature of liquid water, the water pressure on the seabed can not destroy the arrangement of liquid water molecules, so deep-sea water remains liquid. 深海由于阳光无法达到，温度很低，接近零度，由于海水和海底的摩擦，以及深层海水和表层海水之间的热量传递，深海水接近却不能到达零度。 Whether in terms of pressure or temperature, 10,000 meters of deep water is still liquid. However, the seabed environment is more complex, although the overall temperature is relatively low, but due to the active seabed volcanoes and so on, the sea water temperature in some areas is very high, because the sea water pressure is also very high, these seawater become supercritical state.

The point of equilibrium between liquid and gas phase is called critical point. The temperature and pressure at the critical point are called critical temperature and pressure. The critical temperature and pressure of seawater are 374 and 21.7 MPa, respectively. The 10,000-meter seabed pressure exceeds the critical pressure of water. There are many plate cracks on the seabed, which engulf a lot of seawater every year. But the temperature and pressure inside the earth are very high, the sea water will be heated, can easily exceed the critical temperature, and eventually be squeezed out, so the sea water of the ocean will not be reduced by the earth's devouration. At the same time, because the pressure and temperature have reached the critical point, these water will become supercritical state. Scientists have detected that the highest temperature of supercritical water in nature is over 400 degrees Celsius.

Supercritical state has strong water solubility and better compressibility, so now generators will use the production of supercritical water to promote steam turbine power generation, and supercritical state of water solubility is very strong, can bring out many chemicals in the earth, so that seabed chemical energy bacteria have sufficient nutrients and heat supply. That's why scientists believe that seabed hot springs may be the origin of life on Earth.