scholarly journals Supplementary material to "Dynamic changes on Wilkins Ice Shelf during the 2006–2009 retreat derived from satellite observations"

2016 ◽  
Author(s):  
Melanie Rankl ◽  
Johannes Jakob Fürst ◽  
Angelika Humbert ◽  
Matthias Holger Braun
Keyword(s):  
Satellite Observations ◽  
Ice Shelf ◽  
Dynamic Changes ◽  
Supplementary Material

scholarly journals Dynamic changes on Wilkins Ice Shelf during the 2006–2009 retreat derived from satellite observations

2016 ◽  
Author(s):  
Melanie Rankl ◽  
Johannes Jakob Fürst ◽  
Angelika Humbert ◽  
Matthias Holger Braun
Keyword(s):  
Surface Flow ◽  
Satellite Observations ◽  
Ice Shelf ◽  
Dynamic Changes ◽  
Ice Shelves ◽  
Multi Stage ◽  
Multi Temporal ◽  
Horizontal Strain ◽  
Offset Tracking ◽  
The Antarctic

Abstract. Ice shelves serve as important buttresses for upstream areas. Several large ice shelves on the Antarctic Peninsula have disintegrated or retreated, which implied dynamic consequences for upstream ice. The present study aims to assess dynamic changes on Wilkins Ice Shelf during multi-stage ice-front retreat in the last decade. A total area of 2135 ± 75 km2 was lost in the period 2008–2009. The present study uses time-series of SAR satellite observations (1994/96, 2006–2010) in order to derive variations in multi-temporal surface flow from intensity offset tracking methods. Spatial patterns of horizontal strain rate and stress components were inferred during different ice-front retreat stages. These fields are used to explain the different break-up stages and to evaluate the ice-shelf stability. For this purpose, we apply criteria which were forwarded to explain and assess past ice-shelf retreat.

scholarly journals Dynamic changes on the Wilkins Ice Shelf during the 2006–2009 retreat derived from satellite observations

2017 ◽  
Vol 11 (3) ◽  
pp. 1199-1211 ◽  
Author(s):  
Melanie Rankl ◽  
Johannes Jakob Fürst ◽  
Angelika Humbert ◽  
Matthias Holger Braun
Keyword(s):  
Time Series ◽  
Satellite Observations ◽  
Principal Strain ◽  
Strain Rates ◽  
Shelf Area ◽  
Ice Shelf ◽  
Dynamic Changes ◽  
Flow Angle ◽  
Ice Shelves ◽  
Stress Flow

Abstract. The vast ice shelves around Antarctica provide significant restraint to the outflow from adjacent tributary glaciers. This important buttressing effect became apparent in the last decades, when outlet glaciers accelerated considerably after several ice shelves were lost around the Antarctic Peninsula (AP). The present study aims to assess dynamic changes on the Wilkins Ice Shelf (WIS) during different stages of ice-front retreat and partial collapse between early 2008 and 2009. The total ice-shelf area lost in these events was 2135 ± 75 km2 ( ∼  15 % of the ice-shelf area relative to 2007). Here, we use time series of synthetic aperture radar (SAR) satellite observations (1994–1996, 2006–2010) in order to derive variations in surface-flow speed from intensity-offset tracking. Spatial patterns of horizontal strain-rate, stress and stress-flow angle distributions are determined during different ice-front retreat stages. Prior to the final break up of an ice bridge in 2008, a strong speed up is observed, which is also discernible from other derived quantities. We identify areas that are important for buttressing and areas prone to fracturing using in-flow and first principal strain rates as well as principal stress components. Further propagation of fractures can be explained as the first principal components of strain rates and stresses exceed documented threshold values. Positive second principal stresses are another scale-free indicator for ice-shelf areas, where fractures preferentially open. Second principal strain rates are found to be insensitive to ice-front retreat or fracturing. Changes in stress-flow angles highlight similar areas as the in-flow strain rates but are difficult to interpret. Our study reveals the large potential of modern SAR satellite time series to better understand dynamic and structural changes during ice-shelf retreat but also points to uncertainties introduced by the methods applied.

Supplementary material to "Changes in Supraglacial Lakes on George VI Ice Shelf, Antarctic Peninsula: 1973–2020"

2021 ◽  
Author(s):  
Thomas James Barnes ◽  
Amber Alexandra Leeson ◽  
Malcolm McMillan ◽  
Vincent Verjans ◽  
Jeremy Carter ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Ice Shelf ◽  
Supraglacial Lakes ◽  
Supplementary Material

scholarly journals MULTI-SOURCE SATELLITE OBSERVATIONS REVEAL EVOLUTION PATTERN OF RIFTS IN THE FILCHNER-RONNE ICE SHELF, ANTARCTICA

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 1759-1763
Author(s):  
R. Li ◽  
D. Lv ◽  
H. Xiao ◽  
S. Liu ◽  
Y. Cheng ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Rapid Growth ◽  
Temporal Change ◽  
Satellite Observations ◽  
Landsat 8 ◽  
Altimetry Data ◽  
Landsat 8 Oli ◽  
Ice Shelf ◽  
Evolution Pattern ◽  
T1 And T2

<p><strong>Abstract.</strong> This paper presents a systematic fracturing study of the Filchner-Ronne Ice Shelf (FRIS) in Antarctica based on multisource data dating back to 1973. Two fracture maps of FRIS were extracted from Landsat-8 OLI images of 2014&amp;ndash;2015 and MODIS mosaic of Antarctica (MOA) 2008&amp;ndash;2009. The evolution pattern and temporal change of two crucial rifts, Rifts T1 and T2 are analysed for their similarities with the Grand Chasm, which directly induced the previous major calving event of Filchner Ice Shelf (FIS) in 1986. The depth temporal change of Rift T2 was also analysed based on ICESat altimetry data and DEMs reconstructed from ZY-3 and WV-2 stereo images. 3D parameters were also extracted and analysed from DEMs, including rift depth, walls, mélange surface roughness, and mélange thickness. In total, 582 new fractures were extracted from 2004 to 2009 and another 752 from 2008 to 2015. Rifts T1 and T2 showed high activeness, which experienced a rapid growth of 82% and reached &amp;sim;50&amp;thinsp;km in length. Based on all the observations of fracture and rift activity, some regions of ice shelf front in RIS and FIS show some important characteristics that can be related back to the previous calving events.</p>

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