Video: Portage Lake ice rolls alarmingly after glacier calves

A video of the aftermath of a huge chunk of ice breaking off the face of Portage Glacier and crashing with enough force to send waves under the ice was circulated widely on social media Thursday, triggering a fresh discussion about caution in Alaska’s backcountry.

Paxson Woelber, a graphic and web designer who runs an Alaska outdoor site, posted the video and said he hoped to show how powerful and unpredictable the glacier is. As social media has boosted the popularity of glacier and backcountry ice recreation, Woelber said he’s concerned people may not be taking appropriate precautions and gear.

“We’re learning from social media, from amateurs, about what’s safe and what’s not,” Woelber said. “I feel this creates a situation where we’re not actually doing a good job at conveying what’s safe.”

He was especially alarmed this week to see people climbing on the face of the glacier as it is actively at risk of calving, he said. Portage Lake is in Chugach National Forest south of Anchorage, close to Whittier.

As a base rule, Chugach National Forest does not recommend people go out the ice on Portage Lake, said Alicia King, spokeswoman for Chugach National Forest. Those who decide to go should carry safety gear and feel trained enough to rescue themselves or others, she said.

[Frozen Portage Lake seems to be getting more visitors. Is it safe?]

That also means carrying basic pieces of safety gear, Alaska Pacific University professor and Alaska adventurer Roman Dial said in a Thursday interview:

• Helmet

• Dry clothes in a pack in a dry bag that can’t be permeated with water

• Ice grippers

• Ice tools, such as an ice pick, for self-rescue

• A throw rope for rescuing others

All travelers should be prepared to go into the water, Dial said. Federal officials even recommend carrying personal flotation devices onto lake ice.

A fact sheet from the the U.S. Army Corps of Engineers says ice should be at least 1 3/4 inches thick for a person on skis, and 2 inches thick for a person on foot or on skates. Snowmachiners and people walking in single file need 3 inches. A car needs at least 8 inches.

In the city of Anchorage, officials won’t start regular lake ice maintenance until the ice is at least 12 inches thick.

Travelers can check ice thickness with an ice drill or ice auger. It’s also important to monitor air temperatures. If it’s been above freezing for 24 hours or more, the ice begins to lose strength, according to the Army Corps.

Backcountry skaters should also be looking ahead at all times, Dial said. He said he typically slows down when approaching pressure ridges, or ice fragments that are piled up along a line. The ice can be thinner along the ridge, Dial said.

At least one person found that out the hard way recently: A video posted on Facebook this week shows someone falling in along a pressure ridge close to the Begich, Boggs Visitor Center parking lot near Portage Glacier.

People should also stay at least 100 yards away from the face of the glacier, Dial said.

“I’d just use common sense and remember that glaciers are dangerous,” Dial said. “You don’t have to be on a glacier, and if it calves, it calves in a big way.”

For more guidelines about safety during ice travel, check out this information from the U.S. Army Corps of Engineers.