Fears of worsening floods as monsoon rains pound South Asia

Children have been swept away by floodwaters and others killed in landslides caused by heavy monsoon rains across south Asia as the death toll passed 250 Wednesday, with authorities bracing for worse weather in some regions.

Highly anticipated nuclear experiment underway

Neutron stars were recently in the news because the gravitational wave observatory, LIGO, detected a neutron star merger. Neutron stars are very interesting objects. A teaspoon of neutron star matter is so dense it would ...

What Artemis will teach us about living, working on the moon

Humans have not had much of an opportunity to work on the moon. The 12 Apollo astronauts who got to explore its surface clocked in 80 hours in total of discovery time. From their brief encounters, and from extensive analyses ...

Monsoon rains wreak flood havoc across South Asia

Survivors scrambled for higher ground as torrential monsoon rains swept away homes and triggered landslides across South Asia Tuesday, with millions of people affected and at least 180 dead, officials said.

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Water

Water is a ubiquitous chemical substance, composed of hydrogen and oxygen, that is essential for the survival of many known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface. On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation. Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products. Other water is trapped in ice caps, glaciers, aquifers, or in lakes, sometimes providing fresh water for life on land.

Water moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Winds carry water vapor over land at the same rate as runoff into the sea. Over land, evaporation and transpiration contribute to the precipitation over land.

Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world. There is a clear correlation between access to safe water and GDP per capita. However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability. Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70 percent of freshwater is consumed by agriculture.

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