Brash ice, growler ice, bergy bits, and ice bergs
At Aialik Glacier, Patsy and Bella waiting for us on the Endeavour’s swim step. (Photo: Shawn Dilles)
This post continues the Glaciers of Kenai Fjords expedition, gathering photographic evidence of global warming in Alaska with researchers Bruce Molnia, Shawn Dilles, and Kim Angeli on board the Endeavour.
In the morning I went into the engine room to turn on a generator.
For the last few days, I had left the desalinator in the on position, so that it would start when I started either generator. The desalinator is a three-stage high-pressure pump that forces salt water across a permeable membrane in a long tube, flushes the brine overboard, and then pipes the fresh water into the freshwater tank. I opened the small watertight door into the lazarette to check the sight gauge on the tank. It was almost full. With six of us on board, hot showers, and a load of laundry yesterday, we were still making more fresh water than we were using. I closed the door and turned the desalinator off, then started the main engine.
It was a very short run north – not even two miles – up Aialik Bay to the south end of Squab Island. The day was bright, cloudless, and still. The boat slid through the water.
Squab Island is a small rocky island, 350 yards long and 100 yards wide and roughly 125 feet high, a steep little granite knob just under a mile from the giant face of Aialik Glacier. About 150 years ago the glacier covered the Island. We anchored, got in the Scout, and headed to the north end of the island.
We landed and Bruce was up the rock like a goat. The rest of us followed. Birds flew and screamed all around us, mostly mew gulls with their gray jackets and black wing tips and a few pelagic cormorants, as black as scuba divers with long thin necks. We were trespassing, and the gulls let us know it. We found a few squabs – baby gulls – hidden in the grass. There were no raptors anywhere: no eagles, no hawks, no ospreys. I was glad I had left Bella on the boat.
The view from the top was extraordinary. To the northwest was the mile-wide blue ice face of Aialik Glacier, more than three hundred feet tall, its foot in the bay. Turning around clockwise, I could see Skee Glacier to the north, then Lechner Glacier to the east, then milk-blue Aialik Bay leading 20 miles down to the open ocean to the south, lined with saw-toothed cirques, and then Pedersen Glacier to the southwest, shrunken back up slope. Far below, anchored at the foot of the island, the Endeavour was a bathtub toy. All the while, the gulls kept up their screaming.
This was the easiest of the old photo spots to locate. Grant and Higgins had been here in 1909. Bruce had been here in 2006. He and Kim took photographs and recorded the latitude and longitude with a GPS.
Every once in a while, there was a deep double boom from the glacier. The Tlingit word for the sound is “sum-dum,” perfectly onomatopoetic. Sometimes the crack was inside the glacier, and nothing moved. Other times two- or ten-ton slabs of ice calved off from the face and fell into the water. One large chunk sent a wave toward us. It passed over a sandbar between the glacier and the Endeavour and headed for the boat at anchor. It had my attention. But the water at the base of the glacier was shallow and the wave faded fast. Barely a ripple made it to the Endeavour.
Back in the Scout we headed further north to the middle of the bay, looking for another old photo location. Up here the bay was filled with ice, most of it small, but it made a loud rasping noise against the aluminum hull. There were some flat solid pieces of ice with harbor seals lounging on top, watching us silently. The closer we got to the glacier the larger the pieces, with more seals on top. Looking around, we counted 120 seals up sunning on the ice, and almost as many little faces with big black eyes bobbing between the chunks.
There are different terms for different sizes of floating ice, Bruce said. The small chunks from pea-sized to two feet long are called brash ice. Growler ice is the next size up, to about 15 feet long and two feet high (above the water) and with enough mass to do damage if you hit them at cruising speed. Bergie bits are up to 45 feet long and 12 feet high, the size of a large car or small truck, like those holding seals here. Small icebergs are up to 200 feet long and 50 feet high. Then there are proper icebergs which, in Alaska, can be up to a mile long but are rarely more than 50 feet high.
Back on the Endeavour, we headed south down Aialik Bay and dropped anchor at the mouth of Pedersen Lagoon.
- William Urschel