Earthweek: a diary of the planet For the week ending Friday, Dec. 15.

New arctic ‘normal'

A report card on how climate change is affecting the Arctic reveals that permafrost is thawing more quickly, as polar sea ice melts at its fastest pace in 1,500 years. “2017 continued to show us we are on this deepening trend where the Arctic is a very different place than it was even a decade ago,” said arctic researcher Jeremy Mathis. He told the annual meeting of the American Geophysical Union that what’s happening in the Arctic is affecting the rest of the planet. Earlier studies found that changes in Arctic sea ice and temperature can alter the jet stream, a major influence on weather across North America, Europe and Asia.

Aspen clone

An explosion in the number of Utah’s mule deer is threatening the largest and possibly the oldest living organism on the planet. The Pando clone is a forest of more than 47,000 quaking aspens that share a single root system and are genetically identical. The colony emerged about 80,000 years ago from a single seed. But foresters say the Pando clone is tired and aging because its young sprouts are being munched on by the deer, which have grown in numbers since the native wolves disappeared. The deer find the sprouts irresistible.

Noisy seas

The noise pollution produced by ships and marine construction projects in the Gulf of Maine is drowning out the sounds that Atlantic cod and haddock need to communicate with each other, a study says. The National Oceanic and Atmospheric Administration says this is altering the behavior, feeding, mating and socializing of the commercially important fish. Not hearing those signals could threaten their breeding success and survival.

Social arachnophilia

Images of giant and scary-looking spiders posted on social media are helping scientists identify dozens of species that may never have been documented. Writing in the journal Insect Conservation and Diversity, a researcher says she made the discoveries after getting involved with a group of “massive spider nerds.” They venture out at night looking for southern African baboon spiders, then post their findings online. They may have identified 20 to 30 new species.

Iceland rumblings

Iceland’s dormant Skjaldbreidur volcano is showing signs of unrest, with more than 100 tremors of magnitudes up to 3.8 rattling the glacier that covers it. Skjaldbreidur is Iceland’s most dangerous volcano. It last erupted in 1727-28.

Antarctic refuge

The world’s largest marine reserve has just been established in Antarctica’s Ross Sea in what conservationists hail as a “watershed moment” for conservation. The agreement bans commercial fishing in about 72 percent of the reserve.