Search results
Results from the WOW.Com Content Network
Most water in Earth's atmosphere and crust comes from saline seawater, while fresh water accounts for nearly 1% of the total. The vast bulk of the water on Earth is saline or salt water, with an average salinity of 35‰ (or 3.5%, roughly equivalent to 34 grams of salts in 1 kg of seawater), though this varies slightly according to the amount of runoff received from surrounding land.
Water can be polluted, abused, and misused but it is neither created nor destroyed, it only migrates. There is no evidence that water vapor escapes into space." [12]: 26 Every year the turnover of water on Earth involves 577,000 km 3 of water. This is water that evaporates from the oceanic surface (502,800 km 3) and from land (74,200 km 3).
Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering 70.8% of Earth's crust.
The entire ocean, containing 97% of Earth's water, spans 70.8% of Earth's surface, [8] making it Earth's global ocean or world ocean. [23] [25] This makes Earth, along with its vibrant hydrosphere a "water world" [43] [44] or "ocean world", [45] [46] particularly in Earth's early history when the ocean is thought to have possibly covered Earth ...
Fifty percent of the total mass of the atmosphere is located in the lower 5.6 km (3.5 mi; 18,000 ft) of the troposphere. Nearly all atmospheric water vapor or moisture is found in the troposphere, so it is the layer where most of Earth's weather takes place.
When Earth formed around 4.6 billion years ago, some water likely existed in that gas and dust — though much of it would have been vaporized by the sun’s intense heat. How Earth got so much ...
The deuterium to hydrogen ratio for ocean water on Earth is known very precisely to be (1.5576 ± 0.0005) × 10 −4. [35] This value represents a mixture of all of the sources that contributed to Earth's reservoirs, and is used to identify the source or sources of Earth's water.
Water is the most abundant substance on Earth's surface and also the third most abundant molecule in the universe, after H 2 and CO. [23] 0.23 ppm of the earth's mass is water and 97.39% of the global water volume of 1.38 × 10 9 km 3 is found in the oceans. [84]