Scientists have used satellite data to monitor underground water reserves in California’s Silicon Valley, discovering that water levels rebounded quickly after a severe drought that lasted from 2012-15.

The research points to the success of aggressive conservation measures. It also helps to lay the groundwork for low-cost monitoring of subterranean water reserves in California and elsewhere in the world.

Underground stockpiles of water — housed in layers of porous rock called aquifers — are one of the world’s most important sources of drinking water. They sustain human populations in places from Silicon Valley to Beijing. Some 2.5 billion people on Earth rely on aquifers for water, and many of these repositories are being drained more quickly than they can be refilled, according to the United Nations Educational, Scientific and Cultural Organization. Read more

A fear of dying plays a role in people buying bottled water, even though they know it may not be good for them or the planet, a study from the University of Waterloo has found.

The study suggests that most bottled-water advertising campaigns target a deep psychological vulnerability in humans, compelling them to buy and consume particular products. Bottled water ads specifically trigger our most subconscious fear — driving Canadians to buy billions of litres of water annually.

“Bottled water advertisements play on our greatest fears in two important ways,” says Stephanie Cote, who conducted the research while a graduate student at Waterloo. “Our mortality fears make us want to avoid risks and, for many people, bottled water seems safer somehow, purer or controlled. Read more

Most of the water used by people in Egypt comes from the Nile River, which originates from precipitation over mountainous areas in the Ethiopian highlands. In areas far from the Nile River Valley, however, where water is scarce and the population is growing, groundwater is the only available freshwater resource.

UD DOCTORAL CANDIDATE MAHMOUD SHERIF TAKES GROUNDWATER SAMPLES FROM AN AQUIFER IN EGYPT.

Knowing how much water is available in the groundwater aquifers and how fast it is being replenished is vital for providing the population with water for drinking and irrigation. Determining the age of water sources helps in those calculations.

A new study from the University of Delaware looked at chlorine isotopes as chemical tracers to determine the age and origin of groundwaters from the Eastern Desert of Egypt. The research was led by doctoral candidate Mahmoud Sherif and Neil Sturchio from UD and Mohamed Sultan from Western Michigan University. The work resulted in a paper recently published in the Earth and Planetary Science Letters journal. Read more

Earth grew through collisions with Moon-sized to Mars-sized planetary embryos from the inner Solar System, but it also accreted material from greater heliocentric distances, including carbonaceous chondrite-like bodies, the likely source of Earth’s water and highly volatile species.

Understanding when and how this material was added to Earth is critical for constraining the dynamics of terrestrial planet formation and the fundamental processes by which Earth became habitable. However, earlier studies inferred very different timescales for the delivery of carbonaceous chondrite-like bodies, depending on assumptions about the nature of Earth’s building materials. Read more

You might expect that plants hoping to thrive in California’s boom-or-bust rain cycle would choose to set down roots in a place that can store lots of water underground to last through drought years.

But some of the most successful plant communities in the state — and probably in Mediterranean climates worldwide — that are characterized by wet winters and dry summers have taken a different approach. They’ve learned to thrive in areas with a below-ground water storage capacity barely large enough to hold the water that falls even in lean years.

Surprisingly, these plants do well in both low-water and rainy years precisely because the soil and weathered rock below ground store so little water relative to the rain delivered. Read more