Earthweek: a diary of the planet
Ozone hole shrinks The hole above Antarctica in Earth’s protective ozone layer reached its greatest extent of the year on Sept. 26, but was smaller than in recent years, according to scientists who monitor the phenomenon. The National Oceanographic and Atmospheric Administration reports that this year’s hole covered about 7.3 million square miles on that date, compared to more than 8 million square miles last year and more than 10 million square miles during the record year of 2006. But NOAA points out that ozone concentrations at an altitude strongly influenced by man-made ozone-depleting chemicals only dropped to about 25 Dobson units, compared to the less than 10 Dobson units in recent years. “We cannot say that this represents recovery, but it is certainly good news to see this year on the higher side of the average ozone range,” said NOAA’s Bryan Johnson. Out of control Radiation levels have soared in the groundwater beneath Japan’s crippled Fukushima Daiichi nuclear power plant in the wake of torrential typhoon downpours and the forced release of radioactive water being stored around the plant. Officials estimate that 400 tons of radioactive groundwater are now flowing into the Pacific each day. That’s in addition to any runoff from rain on the surface. The level of radiation in a drainage ditch at the facility has also risen exponentially, according to the plant’s operator, the Tokyo Electric Power Co. (TEPCO). Water contaminated with radioactive materials flowed into the ditch when Typhoon Wipha hit the area on Oct. 2. TEPCO says much of the water evaporated, leading to the surge in the density of beta particle-emitting materials in the remaining water. ‘Airpocalypse’ An extremely hazardous concoction of air pollution and fog blanketed the major Chinese city of Harbin and surrounding northeastern areas of the country, forcing schools to close and the cancellation of all air traffic. Public buses also stopped running. Particulate pollution, which doctors say is the most destructive to lungs, was measured at over 500 micrograms per cubic meter, with some downtown Harbin locations reaching as high as 1,000. The World Health Organization says a reading over 300 is hazardous and recommends a daily level of no more than 25.
Indian ‘eruption’ Indian villagers near the border with Myanmar report that an “eruption” with a lavalike flow has charred trees and plants on a nearby hillside. Locals in the Manipur state village of Tusom say a deafening sound on Oct. 13 was accompanied by a flow of the hot liquid. The Press Trust of India quotes officials as saying that mud, water and other discharges were still flowing from the hilltop days later. Since there are no active lava volcanoes on the Indian subcontinent, it’s believed the eruption was from a fresh mud volcano, which can also emit highly flammable gas that was possibly responsible for the charred vegetation and explosion. Earthquakes A sharp 5.2 magnitude temblor in Sumatra’s quake-prone Aceh province killed one villager, injured two others and damaged about 160 homes and other buildings.
• Earth movements were also felt in northern Israel, northern Tunisia, northwestern Mexico and north-central Oklahoma. Tropical cyclones Thousands of residents in southwest Mexico’s Guerrero state were evacuated as Hurricane Raymond churned the Pacific just offshore. But Raymond weakened to a tropical storm and soon moved out to sea.
• Super Typhoon Lekima reached Category-5 force over the open Pacific northeast of Guam. Super Typhoon Francisco weakened from Category-5 force before reaching southern Japan.
• Tropical Storm Lorenzo
formed over the central Atlantic. Monkey chatter At least one species of monkey has been found engaging in polite back-and-forth “conversation” similar to humans. The discovery, published in the journal Current
Biology, could help explain how humans evolved to take turns while speaking. Marmosets are a friendly and peaceful species that help one another raise their young. Princeton University’s Asif Ghazanfar found that marmosets carry on vocalizations even with relative strangers, following a set of unspoken rules of conversation etiquette. He discovered they don’t call at the same time, but instead wait for about 5 seconds after another has finished “talking” before responding. This behavior differs greatly from chimps and other great apes, which don’t vocalize much and don’t take turns when they do. “This makes what we found (in marmosets) much more similar to human conversations and very different from the coordinated calling of animals such as birds, frogs or crickets, which is linked to mating or territorial defense,” said Mr. Ghazanfar. He believes the monkeys may find the polite pattern of conversation relaxing.