The Crack That Echoed Across the Fjord

In Glacier Bay, Alaska, tourists gather each summer near Margerie Glacier — a wall of blue-white ice towering twenty-one stories above the waterline. For long stretches, nothing happens. Then a sound like a rifle shot echoes across the fjord. Then another. Then a deep, groaning crack that seems to come from inside the earth itself. A column of ice the size of a ten-story building sheers away from the glacier face and plunges into the sea.…