seawater

[see-waw-ter, -wot-er]

noun

1. the salt water in or from the sea.

seawater

1. Salt water, normally with a salinity of 35 parts per thousand (3.5%), in or coming from the sea or ocean. Although seawater contains more than 70 elements, most seawater salts are ions of six major elements: chloride, sodium, sulfate, magnesium, calcium, and potassium. The major sources of these salts are underwater volcanic eruptions, chemical reactions involving volcanic matter, and chemical weathering of rocks on the coasts. Seawater is believed to have had the same salinity for billions of years.

Word History and Origins

Origin of seawater¹

before 1000; Middle English see water, Old English sǣwæter; sea, water

Example Sentences

This steady absorption of carbon makes seawater progressively more acidic over time.

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Because radio and GPS signals cannot easily pass through seawater, sonobuoys are vital to modern naval detection systems and they are routinely used by navies during exercises and operations.

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In addition, the shifting weight of seawater also applies pressure to the rocks below.

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Some of these animals can photosynthesize like plants; some harvest algae and seawater to make calcium carbonate for their underwater castles; some produce their own light or glow in the dark.

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Others rely on chemical or physical techniques, including systems that directly remove carbon dioxide from seawater.

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