Dynamic Change of Totten Glacier, East Antarctica
Totten Glacier, East Antarctica, a glacier that holds a 3.9 m sea level change equivalent, has thinned and lost mass for decades. Change in surface elevation calculated from high- resolution DEM differencing shows significant surface lowering rates concentrated in areas of fast flow, hence is probab...
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ftcdlib:qt8qt6g2cw 2023-05-15T13:56:59+02:00 Dynamic Change of Totten Glacier, East Antarctica Li, Xin 118 2016-01-01 application/pdf http://www.escholarship.org/uc/item/8qt6g2cw http://n2t.net/ark:/13030/m5c86xkm en eng eScholarship, University of California http://www.escholarship.org/uc/item/8qt6g2cw qt8qt6g2cw http://n2t.net/ark:/13030/m5c86xkm public Li, Xin. (2016). Dynamic Change of Totten Glacier, East Antarctica. UC Irvine: Earth System Science. Retrieved from: http://www.escholarship.org/uc/item/8qt6g2cw Geophysics Remote sensing Antarctica Glaciology Ice Sheet Mass Balance dissertation 2016 ftcdlib 2016-10-07T22:55:51Z Totten Glacier, East Antarctica, a glacier that holds a 3.9 m sea level change equivalent, has thinned and lost mass for decades. Change in surface elevation calculated from high- resolution DEM differencing shows significant surface lowering rates concentrated in areas of fast flow, hence is probably of dynamic origin. A 26-year long ice velocity time series (1989-2015) consisting of 13 maps is developed from Landsat and interferometric synthetic aperture radar (InSAR) data. We find significant speed-up in ice velocity, especially in 2002-2007, followed by a period of slow decrease in 2010-2014. Comparing the ice discharge with surface mass balance suggests that the glacier mass balance was already negative in 1996 and became more negative into the 2000s. Grounding line mapping using differential InSAR, combined with high resolution topographies of the ice surface and ice draft, reveals a 1,500-2,300 m deep grounding zone. The grounding line extends 15 km inland along two prominent side lobes. Immediately upstream of the grounding line, there is an ice plain which is slightly grounded, only 15-50 m above hydrostatic equilibrium. At the glacier center, we detect a retreat of the grounding line up to 2.6±0.1 km by comparing differential InSAR data acquired 17 years apart. The retreat is asymmetrical along the two lobes, but consistently indicates a total thinning of 11.9±1.5 m from 1996 to 2013. On the ice plain, the glacier is prone to rapid retreat around a region about 7 km long, but inland the bed elevation rises. Sustained thinning will cause further retreat and speed up, but will not be conducive to a marine ice sheet instability. The ultimate cause of the changes is not known, but probably of oceanic origin. Comparison of the velocity time series and reanalysis sub-surface ocean temperatures indicates that Totten Glacier may be very sensitive to oceanic perturbations. Doctoral or Postdoctoral Thesis Antarc* Antarctica East Antarctica Ice Sheet Totten Glacier University of California: eScholarship East Antarctica Totten Glacier ENVELOPE(116.333,116.333,-66.833,-66.833) |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
topic |
Geophysics Remote sensing Antarctica Glaciology Ice Sheet Mass Balance |
spellingShingle |
Geophysics Remote sensing Antarctica Glaciology Ice Sheet Mass Balance Li, Xin Dynamic Change of Totten Glacier, East Antarctica |
topic_facet |
Geophysics Remote sensing Antarctica Glaciology Ice Sheet Mass Balance |
description |
Totten Glacier, East Antarctica, a glacier that holds a 3.9 m sea level change equivalent, has thinned and lost mass for decades. Change in surface elevation calculated from high- resolution DEM differencing shows significant surface lowering rates concentrated in areas of fast flow, hence is probably of dynamic origin. A 26-year long ice velocity time series (1989-2015) consisting of 13 maps is developed from Landsat and interferometric synthetic aperture radar (InSAR) data. We find significant speed-up in ice velocity, especially in 2002-2007, followed by a period of slow decrease in 2010-2014. Comparing the ice discharge with surface mass balance suggests that the glacier mass balance was already negative in 1996 and became more negative into the 2000s. Grounding line mapping using differential InSAR, combined with high resolution topographies of the ice surface and ice draft, reveals a 1,500-2,300 m deep grounding zone. The grounding line extends 15 km inland along two prominent side lobes. Immediately upstream of the grounding line, there is an ice plain which is slightly grounded, only 15-50 m above hydrostatic equilibrium. At the glacier center, we detect a retreat of the grounding line up to 2.6±0.1 km by comparing differential InSAR data acquired 17 years apart. The retreat is asymmetrical along the two lobes, but consistently indicates a total thinning of 11.9±1.5 m from 1996 to 2013. On the ice plain, the glacier is prone to rapid retreat around a region about 7 km long, but inland the bed elevation rises. Sustained thinning will cause further retreat and speed up, but will not be conducive to a marine ice sheet instability. The ultimate cause of the changes is not known, but probably of oceanic origin. Comparison of the velocity time series and reanalysis sub-surface ocean temperatures indicates that Totten Glacier may be very sensitive to oceanic perturbations. |
format |
Doctoral or Postdoctoral Thesis |
author |
Li, Xin |
author_facet |
Li, Xin |
author_sort |
Li, Xin |
title |
Dynamic Change of Totten Glacier, East Antarctica |
title_short |
Dynamic Change of Totten Glacier, East Antarctica |
title_full |
Dynamic Change of Totten Glacier, East Antarctica |
title_fullStr |
Dynamic Change of Totten Glacier, East Antarctica |
title_full_unstemmed |
Dynamic Change of Totten Glacier, East Antarctica |
title_sort |
dynamic change of totten glacier, east antarctica |
publisher |
eScholarship, University of California |
publishDate |
2016 |
url |
http://www.escholarship.org/uc/item/8qt6g2cw http://n2t.net/ark:/13030/m5c86xkm |
op_coverage |
118 |
long_lat |
ENVELOPE(116.333,116.333,-66.833,-66.833) |
geographic |
East Antarctica Totten Glacier |
geographic_facet |
East Antarctica Totten Glacier |
genre |
Antarc* Antarctica East Antarctica Ice Sheet Totten Glacier |
genre_facet |
Antarc* Antarctica East Antarctica Ice Sheet Totten Glacier |
op_source |
Li, Xin. (2016). Dynamic Change of Totten Glacier, East Antarctica. UC Irvine: Earth System Science. Retrieved from: http://www.escholarship.org/uc/item/8qt6g2cw |
op_relation |
http://www.escholarship.org/uc/item/8qt6g2cw qt8qt6g2cw http://n2t.net/ark:/13030/m5c86xkm |
op_rights |
public |
_version_ |
1766264582562643968 |