Climatic and geometric controls on the global distribution of surge-type glaciers: implications for a unifying model of surging

Abstract

ABSTRACT. Controls on the global distribution of surge-type glaciers hold the keys to a better understanding of surge mechanisms. We investigate correlations between the distribution of surge-type glaciers and climatic and glacier geometry variables, using a new global geodatabase of 2317 surge-type glaciers. The highest densities of surge-type glaciers occur within an optimal climatic envelope bounded by temperature and precipitation thresholds. Across all regions with both surge-type and normal glaciers, the former are larger, especially at the cold, dry end of the climatic spectrum. A species distribution model, Maxent, accurately predicts the major clusters of surge-type glaciers using a series of climatic and glacier geometry variables, but under-predicts clusters found outside the climatically optimal surge zone. We interpret the results in terms of a new enthalpy cycle model. Steady states require a balance between enthalpy gains generated by the balance flux and losses via heat conduction and meltwater discharge. This condition can be most easily satisfied in cold, dry environments (thin, low-flux glaciers, efficient conductive heat losses) and warm, humid environments (high meltwater discharges). Intermediate conditions correspond to the optimal surge zone, where neither heat conduction nor runoff can effectively discharge enthalpy gains, and dynamic cycling can result.

Changes in glacier dynamics in the northern Antarctic Peninsula since 1985

“…S5 and S13 in the Supplement) show a decrease of flow speed during retreat (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) followed by an acceleration combined with frontal advance (2010)(2011)(2012)(2013)(2014)(2015). Surge-type glaciers (tidewater as well as land terminating) found in various regions worldwide show similar behavior (Meier and Post, 1969;Sevestre and Benn, 2015). They are characterized by episodically rapid down-wasting, resulting in a frontal acceleration and strong advance.…”

Climate–Glacier Dynamics and Topographic Forcing in the Karakoram Himalaya: Concepts, Issues and Research Directions

“…Furthermore, it has been stated that the large number of surging glaciers in the region suggests a correlation between climate and surge-type glacier locations. Sevestre and Benn [52] found a first-order climatic envelop, where both nonsurge-type and surge-type glaciers can coexist. Their data on mean annual temperature and precipitation could delineate surging clusters that confirm that climate is a primary control on the distribution of surge-type glaciers.…”

The 1982/83 surge and antecedent quiescent phase of Variegated Glacier: revising the original dataset for application in flow line models

“…Nevertheless, there are missing pieces and there is lack of consensus. To resolve the surge mechanism of this particular glacier and compare it with the unifying theory proposed by Sevestre and Benn (2015); find the factors that distinguish this glacier from surrounding normal glaciers; and eventually, for example, judge the surging potential of polar ice masses, further research is necessary. However, there are no ongoing field campaigns resulting in new in-situ measurements and, moreover, analyses of satellite data does not yield new insights (Harrison and others, 2008).…”