We had an absolutely incredible day in Glacier Bay National Park! We checked all the natural history and wildlife boxes, beginning in the geologic realm: this morning as we rounded Jaw Point, we viewed the stunning terminus of the Johns Hopkins Glacier. One of a few remaining tidewater glaciers in Glacier Bay, the Johns Hopkins merges with the Gillman Glacier at the water’s edge. Episodic thunderclaps rang out from calving blocks of ice falling from heights exceeding two hundred feet. If you hear it first, you’ve probably missed seeing it as the thunder follows the visual by several seconds of lag time. Still, we saw several significant events as we stared, slack-jawed at one of the most beautiful landscapes on Earth. Hundreds of harbor seals rested on icebergs near the glacier terminus, seemingly oblivious to our presence and the falling ice.
The Johns Hopkins Inlet not only contains the extraordinary tidewater glacier, it reveals one of the best examples of a geologic suture zone with a “mélange” of folded, faulted, intruded and metamorphosed rocks caught between accreted exotic terranes. In laymen’s terms, this is the geologic equivalent of a smash-up between east and west-bound diesel locomotives. Cleaned and polished by the glacial erosion, the bedrock provides stunning views of faulting, metamorphic alteration, and numerous magmatic intrusions. These formed during and shortly after the accretion of the Alexander and Chugach terrane collided early in the development of the Alaskan landmass.
Rounding Jaw Point and turning south back towards the park entrance, we traversed the eastern edge of the main channel. Along the way we spied brown bears, mountain goats, humpback whales, and innumerable birds — including both the tufted and horned puffin! In between wildlife sightings, we were educated and entertained by our naturalist and photo instructor team. As a special treat, our shipboard guest Dr. Samuel Silverstein spoke about his mountain climbing exploits and his first ascent of Denali’s southeast face. It was a full day indeed!