Alaska largest known yedoma, a permafrost feature that formed thousands of years ago and is now being cut by the Itkillik River on Alaska’s North Slope.

Photo by Eva Stephani.

In northern Alaska, an amphitheater of frozen ground is thawing where a northern river is cutting it, exposing walls of ice. The feature, known by scientists as “yedoma,” is the largest

The plume from a 19,000-acre fire near Volkmar Lake in Interior Alaska on May 29, 2011.

Photo by Ned Rozell.

With their mushroom clouds topped with cauliflower crowns, plumes from wildfire smoke are again a common sight in Interior Alaska, which — with barely a sprinkle of rain — just experien

Barbara Truessel of UAF’s Geophysical Institute sets up a time lapse camera near Yakutat Glacier which will become several glaciers because of melting.

Photo by Chris Larsen.

Not long ago, a glaciologist wrote that the number of glaciers in Alaska “is estimated at (greater than) 100,000.” That fuzzy number, perhaps written in passive voice for a reason, might be correct. But it depends upon how you count.

Hubbard Glacier’s advance toward Gilbert Point near Yakutat, as seen by glaciologist Chris Larsen on May 30, 2011.

Photo by Chris Larsen.

With the return of summer, many natural cycles have resumed up north — visiting birds have invaded tundra and forest, salmon torpedo in loose formation up rivers, and Hubbard Glacier again th

The Mesa site on Alaska's North Slope.

Photo courtesy Mike Kunz.

People tend to think of climate change as a recent phenomenon, but Alaska was once the setting for an environmental shift so dramatic it forced people to evacuate the entire North Slope, according to Michael Kunz, an archaeologist with the Bureau of Land Management.

An alder flycatcher.

Photo courtesy of the Alaska Bird Observatory.

Through the darkness of every spring night, millions of tiny bodies flutter and glide to Alaska from every continent on Earth. Here, songbirds find a summer home, mate, build nests, lay eggs, raise

Hikers trek the Valley of Ten Thousand Smokes on the Alaska Peninsula, walking on a sheet of ash and volcanic rock more than 500-feet-thick.

Photo by Ned Rozell.

One hundred years after the largest volcanic eruption of the 20th century, the Valley of Ten Thousand Smokes is still a moonscape of ash and volcanic rock, without a tree or shrub in sight. The val

This gull swooped from its nesting site on the Yukon River to dive-bomb passing canoeists.

Photo by N. Rozell.

As I drifted with my family past a rocky cliff on the Yukon River, a gull cruised at us like an F-15, diving just over our heads to show its apparent displeasure.

As the gull lo

A satellite image of the northeastern U.S. taken by the Defense Meteorological Satellite Program on Aug. 14, 2003 at 9:03 p.m., when a blackout affected 50 million people.

NOAA/DMSP image.

An Alaska college professor was not surprised when the lights went out over the northern tier of the U.S. and southeast Canada about 10 years ago.

David Newman studies the workings of complex, chaotic systems as part of his research at the University of Alaska Fairbanks. He and three colleagues once wrote a paper about “cascading” power blackouts similar to the largest in the history of the world, which affected 50 million people on August 14, 2003.

An etching from Harper’s Weekly on December 2, 1871, showing the abandonment of three whaling ships trapped in ice off Point Belcher, between Wainwright and Barrow.

Illustration courtesy of Harper’s Weekly.

About 150 years ago, a few days after summer solstice, the gray skies above the Diomede Islands were heavy with smoke from whaling ships set ablaze by Confederate sailors who didn’t know the