Earthweek: a diary of the planet

For the week ending Friday, Dec. 26.

Storm Evacuation

A group of at least five golden-winged warblers “evacuated” nesting areas in eastern Tennessee days before April’s devastating tornado swarm swept across the region. The weather was calm when the birds rushed southward toward the Gulf Coast, hundreds of miles away. Writing in the journal Current Biology, researchers from several institutions say they made the discovery because a group of warblers had been tagged before the outbreak. It’s believed the birds were able to sense infrasound from the deep rumble that tornadoes were generating hundreds of miles away.

Meteor ‘radar’

Scientists may have discovered a new method to provide Earth with warning of potentially dangerous space rocks that could take aim on our planet. By carefully observing changes in streams of plasma from the sun or particles in the solar wind, it could be possible to identify near-Earth objects like the Chelyabinsk meteor that exploded over Russia in 2013. The technique would rely on the magnetic field disturbances that occur in the solar wind when it interacts with positively charged particles left over from collisions of larger objects orbiting the sun.

Old waters of the deep

More water than is contained in all of the world’s rivers, wetlands and lakes combined has been found hiding many miles beneath the surface, and scientists say it’s the oldest water on the planet. A study presented at the American Geophysical Union fall meeting in San Francisco also revealed that the water is reacting with the Earth’s crust to release hydrogen, a potential food source that could be supporting subsurface life . The planet’s oldest water has been estimated to be between 1 billion and 2.5 billion years old.

Toothy attack

For the second holiday season in a row, swimmers trying to escape the heat in northeastern Argentina have been bloodied in a string of attacks by a type of piranha. The most savage of the 10 palometa attacks this month injured 23 people on a beach in Garupá, about 450 miles north of Buenos Aires.

Giraffe decline

One of world’s most iconic and beloved animals is rapidly disappearing from the plains and forests of Africa, according to the Giraffe Conservation Foundation. The charity says the population of wild giraffes has plummeted by more than 40 percent over the past 15 years.

Eruption

An eastern Indonesian volcano erupted without warning on Dec. 19, spewing columns of ash and flows of lava down its flanks. The initial blast from Mount Gamalama, on Ternate Island in North Maluku province, caused nine hikers on the mountain to be injured as they scrambled to safety. Thick ash from the eruption blanketed the main airport of the nearby provincial capital of Ternate, forcing all arrivals and departures to be canceled for days.