Scientists think that helium may offer a good warning of big earthquakes. A containment dome for Chernobyl is finally finished. And a startup hits on a simple method to clean water for schools in poorer parts of the world. Rich Northrup has your weekly news brief.
Helium-4 May Warn of Big Earthquakes
A possible link between the concentration of the helium-4 isotope in groundwater and the amount of stress exerted on inner rock layers of the earth may lead to the development of a monitoring system that could offer advance warning of a big earthquake. Researchers working at the University of Tokyo found that when stress exerted on the earth’s crust was high, the levels of helium-4 released in groundwater also rose. They focused their work on an area near the center of an April 2016 earthquake in southwestern Japan that registered a magnitude 7.3. A pump was used in deep wells to obtain groundwater samples 11 days after the quake. Researchers compared the helium-4 levels of those samples with samples taken in 2010. Helium-4 levels were shown to have increased in samples collected near the epicenter as the gas was released by rock fractures. The researchers say that helium content was higher in areas near the epicenter. They also found that concentrations fell away from the most intense seismic activity.
Chernobyl Reactor Gets a Dome
An arched shelter was placed over the Chernobyl nuclear disaster site in Ukraine in late November. The shelter is one of the world’s largest land-based moving structures. The arch was first designed more than two decades ago and has been under construction since 2010. It covers the steel and concrete cover that had been built after a test at the power plant led to an explosion and fire that sent radioactive ash across Europe 30 years ago. The structure was designed to withstand extreme temperatures, corrosion, and storms. Engineers hope the arch will enable workers, using remote-controlled equipment, to dismantle and remove the fuel and other radioactive components for burial elsewhere.
Low-cost Sand Filter for Clean Water
A startup affiliated with Purdue University in Indiana has developed what it says is a low-cost, low-maintenance slow sand water filter to help provide drinking water to schools and communities in developing parts of the world. The startup installs groundwater wells and provides ceramic filters and slow sand filters in western Kenya where safe water is not readily accessible. The approach uses containers filled with sand and water. At the bottom of the container is a water collection plate. The sand provides a large surface area on which microbial growth occurs. This metabolizes the dissolved and particulate organic material in the water. The filters themselves are made from readily available five-gallon plastic pails or 55-gallon drums. Once water is treated by a filter, a small amount of chlorine is added to the water for final disinfection. According to the company, after 30 minutes of contact with the chlorine, the water is ready to drink.