Discovery of the Fastest Ice Flow along the Central Flow Line of Austre Lovénbreen, a Poly-thermal Valley Glacier in Svalbard

Abstract

Ice flow velocity is a sensitive indicator of glacier variations both controlling and representing the delivery of ice and affecting the future stability of ice masses in a warming climate. As one of the poly-thermal glaciers in the high Arctic, Austre Lovénbreen (AL) is on the northwestern coast of Spitsbergen, Svalbard. The ice flow velocity of AL was investigated using in situ global positioning system (GPS) observations over 14 years and numerical modelling with Elmer/Ice. First, the ice flow velocity field of AL along central flow line was presented and the ice flow velocity is approximately 4 m/a. Obvious seasonal changes of ice flow velocity can be found in the middle of the glacier, where the velocity in spring-summer is 47% larger than in autumn–winter in 2016, and the mean annual velocity increased 14% from 2009 until 2016. Second, the numerical simulation was performed considering the poly-thermal character of the glacier, and indicated that there are two peak ice flow regions on the glacier, and not just one peak ice flow region as previously believed. The new peak ice flow zone found by simulation was verified by field work, which also demonstrated that the velocity of the newly identified zone is 8% faster than the previously identified zone. Third, although our field observations showed that the ice flow velocity is slowly increasing recently, the maximum ice flow velocity will soon begin to decrease gradually in the long term according to glacier evolution modelling of AL.

Evolving Instability of the Scar Inlet Ice Shelf based on Sequential Landsat Images Spanning 2005–2018

“…De Rydt et al [23] reported a general decrease in backstress across the SIIS (especially along its southeast margin) following the 2002 collapse of the LBIS but found that the tributary glaciers (Flask and Leppard) were largely unaffected. Ice flow velocity is a fundamental, crucial, and sensitive parameter in ice sheet dynamics that affects ice sheet stability and determines the extent of ice discharge and future sea level rise [24][25][26][27]. Consistent with the ice front retreat and the reduction of backstress, the surface elevation and ice flow velocity were decelerated and accelerated, respectively.…”

High temporal resolution records of the velocity of Hansbreen, a tidewater glacier in Svalbard

“…modelling of flow of a grounded calving glacier (Vieli et al, 2000), developing glacier-plume and glacier-fjord circulation coupled models to simulate a glacier-ocean system (De Andrés et al, 2021), numerical simulation of the ice flow velocity in the future (e.g. Ai et al, 2019a), and changes of strain rate between neighbouring stakes (Ai et al, 2019b). Further, the dataset is an invaluable source of information on short-term processes such as speed events and seasonal velocity changes (van Pelt et al, 2018).…”

Editorial for the Special Issue: “High-Precision GNSS: Methods, Open Problems and Geoscience Applications”

“…Research in this special issue is also concerned about glacier and climate change. Continuous GPS observations were employed for 14 years to investigate the ice flow velocity in [27]. By analyzing the vertical position time series from 469 European GPS stations, the post-glacial rebound (PGR) in Europe was comprehensively investigated in [28].…”