Journal of Glaciology, Vol. 59, No. 213, 2013 doi: 10.3189/2013JoG12J144 1 Decelerated mass loss of Hurd and Johnsons Glaciers, Livingston Island, Antarctic Peninsula Francisco J. NAVARRO, Ulf Y. JONSELL, MarõÂa I. CORCUERA, Alba MARTIÂN-ESPANÄ OL Departmento de MatemaÂtica Aplicada, ETSI de TelecomunicacioÂn, Universidad PoliteÂcnica de Madrid, Madrid, Spain E-mail:
[email protected] ABSTRACT. A new 10 year surface mass balance (SMB) record of Hurd and Johnsons Glaciers, Livingston Island, Antarctica, is presented and compared with earlier estimates on the basis of local and regional meteorological conditions and trends. Since Johnsons is a tidewater glacier, we also include a calving flux calculation to estimate its total mass balance. The average annual SMB over the 10 year observation period 2002±11 is ±0.15 0.10 m w.e. for Hurd Glacier and 0.05 0.10 m w.e. for Johnsons Glacier. Æ Æ Adding the calving losses to the latter results in a total mass balance of ±0.09 0.10 m w.e. There has Æ been a deceleration of the mass losses of these glaciers from 1957±2000 to 2002±11, which have nearly halved for both glaciers. We attribute this decrease in the mass losses to a combination of increased accumulation in the region and decreased melt. The increased accumulation is attributed to larger precipitation associated with the recent deepening of the circumpolar pressure trough, while the melt decrease is associated with lower summer surface temperatures during the past decade. 1. INTRODUCTION lation rate. In fact, much evidence points to such an Hurd and Johnsons Glaciers are located on Livingston Island increase: an increasing trend in winter accumulation in the (LI), the second largest island in the South Shetland Islands northwestern AP observed in ERA-40 reanalysis data (Miles (SSI) archipelago, which lies nearly parallel to the northern and others, 2008), an increase in the annual total of tip of the Antarctic Peninsula (AP), known as Trinity precipitation days at Faraday/Vernadsky station (Turner and Peninsula (Fig.