It's incredibly cold at the bottom of the ocean – why the water remains liquid

Scientists have explained why water at the bottom of the ocean does not freeze despite extreme cold. The key factors are the salinity of seawater, which lowers the freezing point to -1.9 °C, and the immense pressure at depth, exceeding 1000 bar. Even at temperatures of 1–2 °C, the water remains above its freezing threshold.

At great ocean depths, near-freezing cold prevails, yet the water does not turn into ice. Scientists attribute this to two main factors: salinity and pressure. Seawater contains about 35 grams of salt per kilogram, lowering its freezing point to approximately -1.9 °C. Thus, water at 1–2 °C at depth remains above its own freezing threshold. Additionally, at the bottom of ocean trenches, pressure exceeds 1000 bar, affecting the physical properties of water and ice. An additional factor is hydrothermal vents in areas of volcanic activity, though geothermal heat is not considered the primary cause. The article references a publication by Futura Sciences and is of a popular science nature.