Earthweek: a diary of the planet

Arctic ice max

Arctic sea ice reached its greatest coverage of the year March 17, though it was the second-lowest maximum on record. The U.S. National Snow and Ice Data Center said the coverage on that date was 5.6 million square miles, or only 23,200 square miles more than the record low set on March 7 in 2017. Freak warming this February saw temperatures soar more than 45 degrees above normal in some parts of the Arctic. Temperatures at the North Pole rose above freezing for several days even as the polar region was still in perpetual darkness. Powerful storms in both the Atlantic and Pacific this past winter sent warm water and winds flowing northward into the Arctic.

Evolving immunity

Several species of frogs nearly sent into extinction by a killer chytrid fungus appear to have evolved with resistance to the pathogen. Their populations in Panama alone have now rebounded to previous levels. A hybrid strain of the fungus has been responsible for numerous

die-offs of amphibians worldwide since the 1980s. It’s believed to have emerged because of the global trade in amphibians. Though not all species have evolved quickly enough to survive, the deep croaks of frogs and toads are returning to some of the oncequiet streams in Panama, according to researchers from the University of Pittsburgh. But they caution that the amphibians are still infected with the fungus; they are just better able to limit its growth and damage.

Earthquakes

A powerful magnitude 5.3 earthquake rattled parts of Southern California, with the epicenter in the

Pacific Ocean off the coast of Los Angeles and near the Channel Islands. There were no injuries reported. In addition, at least 53 people were injured when a magnitude 5.3 quake struck the Iran-Iraq border. A deep tremor beneath Bolivia rocked buildings as far away as the Brazilian metropolis of São Paulo. Earth movements also were felt in central Taiwan and El Salvador.

Tropical cyclones

Torrential rains from Tropical Storm Josie killed four people as they swamped villages in Fiji. Cyclone Iris churned the Coral Sea as former Super Typhoon Jelawat lost force over the North Pacific. African divide

A widening fissure that has appeared for miles across the landscape of Kenya’s Rift Valley has wrecked homes and destroyed a stretch of highway. One family said a crack developed in their cement floor and started spreading after weeks of rain, floods and tremors. “The cracks run almost in a straight line, so you can project. If you see a crack coming your way, get away,” said geologist David Adede. The East African Rift Valley is splitting the African tectonic plate in two. Scientists believe the split will, over the next 50 million years, see a long slice of East Africa break away from the continent. Whaling season

Japan’s whaling fleet returned home after slaughtering 333 of the marine mammals since November. The fleet of five ships operated this season without interference from anti- whaling groups for the first time in seven years, allowing the hunt for minke whales to proceed without disruption or confrontation. The most aggressive of the campaigners, Sea Shepherd, announced in 2017 that it was taking a break from its efforts to thwart Japan’s whaling by clashing with the fleet in the Southern Ocean.

Eruption

Vanuatu’s Manaro Voui volcano produced fountains of lava and a plume of ash that damaged crops, water supplies and buildings on Ambae Island.

The volcano is one of the world’s most dangerous and began erupting in the island nation this past September. All of Ambae’s 11,000 residents were evacuated at that time and had just returned before this most recent activity.