A new Antarctic Peninsula glacier basin inventory and observed area changes since the 1940s

A.J Cook,T Murray,A.J Luckman,D.G Vaughan

doi:10.1017/s0954102014000200

Abstract

AbstractGlaciers on the Antarctic Peninsula have recently shown changes in extent, velocity and thickness, yet there is little quantification of change in the mass balance of individual glaciers or the processes controlling changes in extent. Here a high-resolution digital elevation model and a semi-automated drainage basin delineation method have been used to define glacier systems between 63°S–70°S on the mainland and surrounding islands, resulting in an inventory of 1590 glacier basins. Of these, 860 are marine-terminating glaciers whose ice fronts can be defined at specific epochs since the 1940s. These ice front positions were digitized up to 2010 and the areas for all individual glacier basins were calculated. Glaciological characteristics, such as geometry, slope and altitudes, were attributed to each glacier, thus providing a new resource for glacier morphological analyses. Our results indicate that 90% of the 860 glaciers have reduced in area since the earliest recorded date. A north–south gradient of increasing ice loss is clear, as is distinct behaviour on the east and west coasts. The area lost varies considerably between glacier types, with correlations apparent with glacier shape, slope and frontal-type. Temporal trends indicate a uniform retreat since the 1970s, with a period of small re-advance in the late 1990s.

Highlights

Glaciers throughout the Antarctic Peninsula (AP) have undergone extensive change in recent decades (Cook et al 2005, Pritchard & Vaughan 2007, Pritchard et al 2009, Kunz et al 2012) and are subject to rapid climate warming from both the atmosphere and ocean (Barrand et al 2013a)
Outlet glaciers drain to the east and west from the plateau of the AP ice sheet, and ice caps, mountain glaciers and piedmonts are prevalent along the margins and adjacent islands
We describe how a new 100-m resolution digital elevation model (DEM) (Cook et al 2012), combined with a semi-automated drainage basin delineation approach, has ensured a consistent identification of boundaries, resulting in a new inventory of glacier drainage basin outlines that can provide a resource for future mass balance studies

Summary

Introduction

Glaciers throughout the Antarctic Peninsula (AP) have undergone extensive change in recent decades (Cook et al 2005, Pritchard & Vaughan 2007, Pritchard et al 2009, Kunz et al 2012) and are subject to rapid climate warming from both the atmosphere and ocean (Barrand et al 2013a). We describe how a new 100-m resolution digital elevation model (DEM) (Cook et al 2012), combined with a semi-automated drainage basin delineation approach, has ensured a consistent identification of boundaries, resulting in a new inventory of glacier drainage basin outlines that can provide a resource for future mass balance studies We use these boundary outlines alongside the existing coastalchange and glaciological maps of Antarctica dataset of historical ice front positions (Williams et al 1995, Cook et al 2005, Ferrigno et al 2006, 2008, 2009) and, as a result, increase the number of marine-terminating glaciers for which a record of frontal change can be defined from 244 (Cook et al 2005) to 860 glaciers. We calculate the area changes for all 860 glaciers, from records as early as 1945 to 2010, and discuss correlations between glacier characteristics and spatio-temporal patterns of change

Methods

Findings

Conclusion