Top 10 water facts

A fizz. When a piece of iceberg ice melts, it makes a fizzing sound called "Bergie Seltzer". This sound is made when the water-ice interface reaches compressed air bubbles trapped in the ice. As this happens, each bubble bursts, making a 'popping' sound. The bubbles contain air trapped in snow layers very early in the history of the ice, that eventually got buried to a given depth (up to several kilometers) and pressurized as it transformed into firn then to glacial ice.

68°C (154.4°F). The boiling point of water depends on the pressure. On top of Mount Everest, the pressure is about 260 mbar (26.39 kPa) and the boiling point of water is 69 °C. (156.2 °F). In contrast, water can still remain liquid near deep hydrothermal vents, even if the temperature is very high.

Heavy water has greater density. Heavy water contains deuterium instead of common hydrogen-1. In its pure form it has a density about 11% greater than water, but otherwise, it is physically and chemically similar. It is not radioactive. Because of greater density and stronger hydrogen-oxygen bonds, its behaviour is slightly different in some biochemical reactions. It may be toxic, but only when a large fraction of water (> 50%) in higher organisms is replaced by heavy water.

A speed of light is always constant. The speed at which light propagates through transparent materials, such as glass or air, is less than c. However, this "slowing of the light" is only due to the fact of photos being absorbed and re-emitted after a slight delay between atoms. When a photon is emitted, it's speed is always c. In exotic materials like Bose–Einstein condensates near absolute zero, the effective speed of light may be only a few metres per second.

In Antarctica. With a salinity level of over 40%, Don Juan Pond is the saltiest of the Antarctic lakes. This salinity allows the pond to remain liquid even at temperatures as low as −50 °C (−58 °F) due to the interference of salts with the bonding of water molecules. Don Juan Pond was discovered in 1961 by George H. Meyer.

Great Lakes freighters. Since the freshwater lakes are less corrosive to ship than the salt water of the oceans, many of the Lakers remain in service for long periods and the fleet has a much higher average age than the ocean-going fleet. The St. Mary's Challenger, built in 1906, is currently the oldest boat on active duty on the Lakes.

Tigers living in the southeast Asia are semi-aquatic. They spend much of their time in rivers and feed on fish. Young tigers like to play in the water, and adults often take a bath just to keep cool during hot days.

Water salinity. Launched June 10, 2011, Aquarius is NASA’s first satellite instrument specifically designed to study the salt content of ocean surface waters. The complete first year dataset of NASA's Aquarius instrument reveals seasonal changes in the Amazon River's plume. Depending on the prevailing currents, the river's freshwater outflow heads east toward Africa or bends up north to the Caribbean.

12 000 years old. The Baltic Sea is one of the youngest seas in the world. It was formed after the last ice age as an ice-lake, which later turned into a sea.

Southern foothills of the Himalayas. Mawsynram village in northeast India has the highest average annual total precipitation in the world (11,872 mm = 467.4 in). There, hot and moist air from the south of India approaches Himalayas. It rises up, cools and loses water.