3 Retreat, Stabilization, and Regrowth of Crane Glacier
Remote sensing observations collected around the collapse event have been thoroughly discussed in the literature. Ice shelf terminus retreat and thinning preceded the rapid collapse of the LBIS in February to March of 2002 (Glasser & Scambos, 2008). We refine the following record found in the literature, which showed little change at Crane immediately post-collapse in 2002 (Scambos et al., 2004), followed by accelerated mass loss from 2003-2007 (Scambos et al., 2011), and a slow deceleration of ice loss from 2008-2013 (Wuite et al., 2015).
The MICI hypothesis, invoked for Crane, is predicated on the idea that calving by cliff failure (and terminus retreat into thicker ice with taller cliffs) causes an acceleration of the calving rate that outpaces the ability of Crane to viscously thin and inhibit calving. Below, we reframe and extend the observational record of Crane Glacier from 2002-2021 to highlight three distinct periods with the MICI hypothesis in mind: the initiation of fracture processes and accelerating terminus retreat, the stabilization of the glacier terminus, and the regrowth and return to glacier equilibrium with the modern climate. We argue these data show the disequilibrium behavior of Crane Glacier during retreat, including a positive geometric feedback as retreat accelerates, and hysteresis in its response as it returns to an advanced but thin configuration within the modern climate.