The swell from the Tohoku tsunami was likely only a foot high (30 cm) when it reached the Sulzberger Ice Shelf, but the consistency of the waves created enough stress to cause the calving.

Traveling sometimes by skis, sometimes on foot, sometimes in kayaks, they negotiated endless mazes of rafted ice intersected by slushy leads.

Unfortunately, this meant climbing up a sheer hundred-foot cliff-face of solid ice.