Groundwater on EARTH Magazine

Easter Island inhabitants drank brackish water to survive

Thu, 17 Jan 2019 13:33:07 -0500

Graduate student Tanya Brosnan, who led a recent study of coastal seeps — where fresh groundwater flows into the ocean — on Rapa Nui (Easter Island), carries out conductivity measurements near Ahu Tongariki on the east side of the island. Credit: Carl Lipo.

The remote Chilean island of Rapa Nui, also known as Easter Island, is famous for its 961 giant stone statues and monuments, erected between 1200 and 1600. Called moai, these statues have been a mystery for years, especially considering just a few thousand people inhabited the small, resource-limited Pacific island nearly 3,700 kilometers west of Chile. “Why did people put the statues where they did?” asks Carl Lipo, an archaeologist at Binghamton University in New York. The answer, according to new research, may have something to do with the civilization’s water supply.

Neonicotinoids: Prominent pesticides escape into the environment

Fri, 14 Apr 2017 09:48:30 -0400

Credit: K. Cantner, AGI.

The 1990s was a watershed era in pest control — and, by extension, agriculture — thanks to a particular bit of chemical innovation. With the emergence of a compound called imidacloprid onto the insecticide market, farmers — from those growing rice, corn and other staples, to orchard owners cultivating fruit trees, to backyard gardeners tending vegetable patches — had a powerful new tool with which to combat aphids, beetles, weevils, whiteflies and a host of other insects with a knack for damaging crops.

Maui reef degradation linked to contamination in coastal groundwater

Wed, 29 Mar 2017 14:25:27 -0400

Honolua Bay, Maui, a designated marine life conservation district, was one location studied by researchers examining links between land use, water quality and coral reef health at coastal sites around Maui. The bay is surrounded by a watershed featuring potential sources of nutrient runoff from human activities, such as golf courses and sewer systems. Credit: Hawaii Savvy, CC BY 2.0.

Submarine groundwater discharge — the flow of fresh and brackish groundwater from land to sea — can transport contaminants to coastal ecosystems. But little is known about the direct impacts of this process on marine communities. In a new study published in PLOS ONE, researchers examined links between land use, water quality and coral reef health at coastal sites around Maui, finding that anthropogenic contaminants delivered via submarine groundwater are a source of chronic stress to nearshore marine ecosystems.

Down to Earth With: Hydrogeologist Shemin Ge

Fri, 19 Aug 2016 14:51:51 -0400

Shemin Ge is a hydrogeologist at the University of Colorado Boulder and GSA's 2016 Birdsall-Dreiss Lecturer. Credit: Connie Ge.

" graduated from high school in China, the country was still in the throes of the Cultural Revolution. During this movement, which lasted from 1966 to 1976, many colleges and universities were closed, and Ge, like most teenagers from urban areas, was sent to work in the countryside. She was assigned to a brick-making factory, where she had to haul heavy, machine-molded bricks outside so they would dry in the sun. Unless the forecast called for good weather, the teens also had to cover the bricks each evening to prevent them from cracking in the rain.

Treated water that's too pure lets arsenic sneak in

Wed, 23 Dec 2015 12:50:45 -0500

Orange County is tackling California's water shortage by recycling wastewater into tap water. Credit: WPPilot, CC BY-SA 3.0.

With California’s water resources dwindling to alarmingly low levels, the Orange County Water District (OCWD) has pioneered a high-tech approach for recycling wastewater into potable tap water instead of discharging it into the ocean. The purification process is so thorough, however, that it might actually make the water too clean: In a new study, researchers have found that the ultra-purified water is vulnerable to contamination by naturally occurring arsenic in underground storage aquifers.

Lead-up to Icelandic earthquakes seen in groundwater chemistry

Tue, 09 Dec 2014 10:47:18 -0500

The Husavik-Flatey Fault cuts across part of northern Iceland near the town of Husavik. An earthquake on this fault in 2012 was one of two found recently to correlate with significant changes in groundwater chemistry measured months before the quakes occurred. Credit: Alasdair Skelton.

Scientists tracking groundwater in Iceland have reported that significant shifts in the water’s chemistry occurred months prior to earthquakes in 2012 and 2013. It’s far too early to apply the findings to earthquake hazard assessment, researchers say, but the results suggest that precursory groundwater changes may also herald earthquakes elsewhere and point toward a potential means of future seismic monitoring.

A dry and ravaged land: Investigating water resources in Afghanistan

Mon, 08 Dec 2014 10:15:48 -0500

A tale of three Afghanistans: Deserts, mountain streams and growing cities. Credit: top and middle: Thomas J. Mack, USGS; bottom: ©iStockphoto.com/MieAhmt.

Aside from the front-page issues of war and politics, one of Afghanistan’s most critical national needs is safe and reliable supplies of water. The United Nations estimates that Afghanistan’s current population of about 31 million will increase by nearly 80 percent by the year 2050 to approximately 56 million. Such an increase will raise demand on the country’s already stressed water resources. In addition, recent research suggests that global climate change could alter precipitation patterns in Afghanistan. In particular, both the amount and the timing of snowfall received at higher elevations could change, impacting the major source of water for many areas in Afghanistan.

Rainwater penetrates into ductile crust

Tue, 04 Nov 2014 11:52:06 -0500

Researchers found that rainwater penetrates into the brittle-ductile transition zone beneath New Zealand's Southern Alps. Credit: ©Jörg Hempel, CC-BY-SA-3.0-de.

Rainwater is capable of percolating deeper into Earth’s crust than once thought possible, according to a new study. The finding could impact our understanding of mountain building, the behavior of rock deep underground and the formation of hydrothermal mineral deposits.

Colorado River Basin sees severe groundwater depletion

Thu, 25 Sep 2014 13:10:13 -0400

Over the past 14 years, the Colorado River Basin has experienced its worst drought since precipitation records have been kept, starting in the 1960s. The basin supplies water used for agriculture and in households in seven states, affecting more than 40 million people. In a study recently published in Geophysical Research Letters, researchers have found that the reservoirs that store water in the basin are at record low levels. What’s more, the research shows that in addition to shrinking reservoirs, groundwater is being depleted much faster than previously thought, which could have major implications for the region’s future water security.

Arsenic in wells in Vietnam suggests dig-deeper approach has issues

Mon, 09 Sep 2013 14:05:41 -0400

Laura Erban collects water samples to test for arsenic in wells in Vietnam. Courtesy of Laura Erban

For years, scientists and public health officials have known that arsenic threatens the water supplies of millions of people in the heavily populated floodplains of Southeast Asia. A recent study centers on Vietnam’s Mekong Delta, but has profound implications for the people of the entire region. In Vietnam, arsenic is naturally hosted in sediments drained off the Himalayas, which wash into the Mekong. Within the delta sediments, microbes dissolve the carcinogen, facilitating its movement. According to previous studies, arsenic can be avoided by “digging deeper” — by drilling farther into the aquifers, past the poisoned groundwater. But now, a team of researchers has found that digging deeper may actually accentuate arsenic poisoning rather than alleviate it.

Arsenic levels in China may be predicted by modeling

Mon, 09 Sep 2013 13:44:45 -0400

Guifan Sun and his students collect water samples in China. Courtesy of Prof. Sun, China Medical University, Shenyang

In China, arsenic poisoning from groundwater has been a known chronic health issue since at least the 1970s. From 2001 to 2005, the Chinese Ministry of Health tested 450,000 wells, 13 percent of which exceeded World Health Organization (WHO) arsenic standards. However, numbers could be far worse, as only about 12 percent of Chinese counties were screened. Now, researchers from the Swiss Institute of Aquatic Science and Technology (Eawag) and China Medical University have developed a predictive model for arsenic groundwater contamination that they say could more efficiently determine regions where high-level arsenic contamination is most likely to occur. Their results, published in Science, showed that main arsenic risk is most likely in northern China.

The energy-water nexus: Managing water in an energy-constrained world

Thu, 13 Jun 2013 11:06:16 -0400

Global water resource availability: The majority of Earth's water is in a form that is not convenient for human use. Only about 3 percent of it is freshwater, and nearly two-thirds of that exists as ice and permanent snow cover. The vast majority of the remaining freshwater exists in groundwater aquifers, much of which cannot be practically extracted. Kathleen Cantner, AGI

Water can be tricky. With too little, crops die, industries move away, power plants fail, ecosystems suffer and people go thirsty. With too much, floods ruin infrastructure, destroy crops, spread waterborne diseases, and disrupt flows of clean water, wastewater, power and transportation. We want water at the right time and in the right place because moving and storing water require effort. We also want it at the right quality and the right temperature. Saline water, brackish water and polluted water are abundant but costly to treat. Water that’s too warm won’t cool power plants effectively and can damage ecosystems, while water that’s too cold can burst pipes and damage infrastructure.

Benchmarks: December 3, 1984: Bhopal gas leak kills thousands

Thu, 05 Jan 2012 06:41:58 -0500

On Dec. 3, 1984, Aziza Sultan woke to the sound of coughing. When she opened her eyes, she could see that the room was filled with a white haze. She heard people shouting “Run, run.” Then she too began to cough. Each breath burned her lungs.

Extinction-era coal linked to Chinese cancer epidemic

Thu, 05 Jan 2012 06:41:58 -0500

At the close of the Permian, 252 million years ago, conditions on Earth took a turn for the worse, nearly wiping out life on land and at sea in the planet’s most severe extinction event. Now, eons later, geologists are implicating a coal seam that dates to the “Great Dying” at the Permian-Triassic boundary in one of the modern world’s worst cancer epidemics.

Geoscientists Without Borders: Geologists Lend a Hand

Thu, 05 Jan 2012 06:41:58 -0500

Seismic profiling in Chiang Mai, Thailand. Boise State University - Geoscientists _Without_ Borders

Boise State University student Eric Rothwell collects sediment cores in northern Thailand. Spencer Wood

Rothwell and Chiang Mai University student Tharaporn Bundarnsin collect magnetic data at an archaeological site in northern Thailand. Spencer Wood

Craig Beasley’s one-year term as president of the Society for Exploration Geophysicists had a challenging start. After about two months in office, a magnitude-9-plus earthquake struck off the coast of Sumatra on Dec. 26, 2004, triggering a powerful tsunami that killed more than 225,000 people and left hundreds of thousands homeless.

Impossible Odds, Irrepressible Hope: Pakistan's water woes and the science that can solve them

Thu, 05 Jan 2012 06:41:58 -0500

U.S. Geological Survey researchers work with Pakistani researchers to collect water samples. Courtesy of Ingrid Verstraeten, USGS

A water researcher examines water dyed from cotton production in Faisalabad, Pakistan. Courtesy of Ingrid Verstraeten, USGS

Pakistani and USGS scientists reviewing sampling techniques near Islamabad. Courtesy of Ingrid Verstraeten, USGS

At a demonstration farm near Islamabad, researchers work to improve irrigation efficiency. Courtesy of Ingrid Verstraeten, USGS

Most residents of developed countries don’t think about their water running out or worry about their water leading to the death of their children. In Pakistan, those are distinct possibilities.

Mapping safer drinking water

Thu, 05 Jan 2012 06:41:58 -0500

Warmer colors represent a higher risk of arsenic-contaminated groundwater, while blues represent low-risk areas. Winkel L., Berg M., Amini M., Hug S.J., Johnson C.A., Nature Geoscience 1, 536-542 (2008)

Beginning in the 1970s, international aid agencies dug hundreds of thousands of wells in Bangladesh to help people access clean drinking water. The effort curbed diarrheal diseases, but it led to a new problem: arsenic poisoning.

Mining for iron oxides in coal mine sludge

Thu, 05 Jan 2012 06:41:58 -0500

A young miner in Pittston, Pa., in 1911. Over the past 200 years, miners have extracted billions of tons of coal in Pennsylvania, but drainage from abandoned mines has left the waterways polluted. Library of Congress

Large settling ponds aerate mine discharge, allowing dissolved iron to oxidize. Over time, iron oxide settles to the bottom and the clear water flow out. Courtesy of Method Media

These troughs spread and slow the water's flow, giving it time for chemical reactions to occur and for the iron oxide to settle to the bottom. Courtesy of Method Media

A passive treatment system at the abandoned Marchand mine in Pennsylvania reduces the water's iron, turning its color from bright orange to clear, as shown here. Bob Hedin

The billions of tons of coal that miners extracted from Pennsylvania’s ground over the past two centuries have long gone up in smoke, but their legacy lives on in the state’s rivers and waterways. Nasty discharge — often with sky-high metal concentrations — from thousands of abandoned coal mines has been polluting Pennsylvania’s streams and groundwater.