Tarr Inlet, Margerie, and the Grand Pacific
Tarr inlet stretches over nine miles from its mouth to its northern end. It is less than two miles wide and clamped between towering rock walls polished and scarred by the glacier. The fjord terminates in a gentle dirty-brown slope marbled with swaths of white swirling into the distant peaks. This is the Grand Pacific Glacier, now sixty-five miles from Icy Strait. Less photogenic than the advancing glaciers, it is more historically and geologically fascinating. It is the glacier that carved Glacier Bay. All the others were once tributaries of this river of ice. Overcoming my terrestrial prejudices and perspective, I regarded the scene with amazed eyes. The stone walls of the fjord plunging precipitously to the placid blue-green waters continue to plummet, unseen, 1200 feet to the inlet floor — more than five thousand feet in all. The gentle, hummocky slope of the Grand Pacific Glacier at the end of Tarr Inlet isn’t a plain of ice resting on the shore; it is a titanic plug of ice, filling another five miles of the valley. The water just in front of the terminal moraine of the Grand Pacific is eight hundred feet deep, and the ice beyond is over nine hundred feet thick.
As fascinating as I found the Grand Pacific, the glacier that received the most press in the cruise literature and on-board propaganda — one of the few remaining tidewater glaciers in North America — is tucked behind a rugged outcrop at the northern end of Tarr Inlet. Margerie Glacier wasn’t visible until we sailed within three miles of the end of the fjord. The glacier is picturesque: blue-white ice spires tower over the silted waters, and massive slabs calve thunderously into the bay. Perhaps more importantly, cruise ships can approach much closer to Margerie than the larger-but-restricted Johns Hopkins Glacier (more about that later) and the vast Hubbard Glacier.
Margerie is a petite glacier compared to Hubbard (if petite can even be an appropriate adjective for a 21-mile long stream of ice); its face is barely a mile wide. The ice reaches 250 feet above the water and one hundred feet below. Though you wouldn’t know by looking, Margerie is a hanging glacier. Since Tarr Inlet is eight hundred feet deep at its northern end, the floor of the side vale from which Margerie Glacier flows is 600 feet above the bottom of the main valley. As the ice slides beyond the lip of the hanging valley, it becomes unsupported and shears (calves) from the face of the glacier. The ice progresses about 6 feet each day (or 2000 feet every year). With our climate steadily warming, melting has outpaced the flow during the last decade, a trend that has accelerated since 2017. It appears that Margerie is no longer stable and is gradually retreating.
We floated at the northern end of Tarr inlet for an hour as the captain slowly rotated the ship to provide views to port and starboard. When I could spare a glance from the faces of the glaciers and the soaring rock walls, I noticed tiny dots moving between and upon the bergs floating around us. Looking through a telephoto lens, I saw dozens of six-foot-long harbor seals. It was a jolt as my sense of scale lurched to accept this new perspective.
As the afternoon wore on, we reversed course and glided through the ice-strewn water of Tarr Inlet back to the fork, and then turned right into Johns Hopkins Inlet. One and one-half miles inside the inlet, we passed Lamplugh Glacier as we glided westward. Johns Hopkins Inlet stretches west for four miles before rounding a point and veering southwest for another six miles to the face of the glacier. We could only sail as far as the turn: large vessels are prohibited beyond the point from May to September, and all craft (including kayaks) are forbidden from May to July. Johns Hopkins Inlet is a harbor seal nursery, and restrictions are in place to protect the pups.
The inlet is narrower than Tarr, less than one and one-half miles. It was unnerving to see a 964-feet-long, 122 -feet-wide, 204 -feet-tall cruise ship gliding so near monumental rock walls. As with Tarr Inlet, these ramparts continue to plummet precipitously beneath the sea to the valley bottom 1200 feet below the surface — our 26-foot draught wasn’t a problem. The captain’s impressive skill manifested itself as the ship swiveled to reverse course at the crook of the inlet.
As we rounded the point, Johns Hopkins Glacier appeared six miles away. The face of the glacier is about the same size as Margerie Glacier: one mile wide and about 250 high. Below the waterline the story is different. Johns Hopkins Glacier extends two hundred feet below the surface and has a substantial “ice foot” that protrudes from the face below the water. The glacier is known for submarine calving. The park website notes that “these basal bergs rise suddenly and unexpectedly, emerging, sometimes explosively, without warning at the water surface.”
Until recently Johns Hopkins Glacier was the only glacier on the east side of the Fairweather Range still advancing. That is, unfortunately, no longer the case. According to the park rangers, since 2016 the terminus of the glacier seems to be at best stable, not advancing.
