The Response of Brewster Glacier to Five Decades of Climate

Climate Interactions ◽

Geodetic Mass Balance ◽

Reduced Rate ◽

<p>Small perturbations in climate can produce measurable changes to the size of a glacier. Documenting such changes is important for quantifying water storage changes, and understanding glacier-climate interactions. By using all available geodetic data, such as Landsat imagery, Shuttle Radar Topography Mission, GNSS and photogrammetric techniques, as well as ground penetrating radar for the construction of a bed DEM, it is found that Brewster Glacier decreased in volume from 1967 to 2017, losing ∼56% of its volume, with a period of volume increase of ∼10% from 1986 to 1997. The overall pattern of geodetic mass balance is similar to the glaciological mass balance record, however, the geodetic method tends to show more negative values by an average of ∼0.6 m w.e. Contrary to many other New Zealand glaciers, which experienced an advance from 1983 to 2008, Brewster Glacier continued to retreat by 390 m during the study period, at an average rate of 7.8 m a⁻¹, but at a signiﬁcantly reduced rate of ∼2 m a⁻¹ from 1997 until 2005. By comparing the records of Brewster Glacier and Fox and Franz Josef glaciers, we explore the diﬀerences in response and reaction times resulting from glacier area-altitude distribution, and climatic setting. Furthermore, DEMs produced by this study are now available for use by a New Zealand wide glacier monitoring programme.</p>

The Response of Brewster Glacier to Five Decades of Climate

10.26686/wgtn.17072714 ◽

2021 ◽

Author(s):

◽

Merijn Thornton

Keyword(s):

New Zealand ◽

Mass Balance ◽

Average Rate ◽

Landsat Imagery ◽

Reaction Times ◽

Climate Interactions ◽

Geodetic Mass Balance ◽

Reduced Rate ◽

Minor Imbalance of the Lowermost Italian Glacier from 2006 to 2019

Water ◽

10.3390/w12092503 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2503

Author(s):

Jessica De Marco ◽

Luca Carturan ◽

Livia Piermattei ◽

Sara Cucchiaro ◽

Daniele Moro ◽

...

Keyword(s):

Mass Balance ◽

Laser Scanning ◽

Climate Changes ◽

Average Rate ◽

European Alps ◽

Surface Dynamics ◽

Solid Precipitation ◽

Airborne Laser ◽

Geodetic Mass Balance ◽

Annual Balance

The response of very small glaciers to climate changes is highly scattered and little known in comparison with larger ice bodies. In particular, small avalanche-fed and debris-covered glaciers lack mass balance series of sufficient length. In this paper we present 13 years of high-resolution observations over the Occidentale del Montasio Glacier, collected using Airborne Laser Scanning, Terrestrial Laser Scanning, and Structure from Motion Multi-View Stereo techniques for monitoring its geodetic mass balance and surface dynamics. The results have been analyzed jointly with meteorological variables, and compared to a sample of “reference” glaciers for the European Alps. From 2006 to 2019 the mass balance showed high interannual variability and an average rate much closer to zero than the average of the Alpine reference glaciers (−0.09 vs. −1.42 m water equivalent per year, respectively). This behavior can be explained by the high correlation between annual balance and solid precipitation, which displayed recent peaks. The air temperature is not significantly correlated with the mass balance, which is main controlled by avalanche activity, shadowing and debris cover. However, its rapid increase is progressively reducing the fraction of solid precipitation, and increasing the length of the ablation season.

Observations of enhanced thinning in the upper reaches of Svalbard glaciers

The Cryosphere ◽

10.5194/tc-6-1369-2012 ◽

2012 ◽

Vol 6 (6) ◽

pp. 1369-1381 ◽

Cited By ~ 42

Author(s):

T. D. James ◽

T. Murray ◽

N. E. Barrand ◽

H. J. Sykes ◽

A. J. Fox ◽

...

Keyword(s):

Mass Balance ◽

Average Rate ◽

Winter Precipitation ◽

Svalbard Archipelago ◽

Ice Surface ◽

Considerable Research ◽

Elevation Data ◽

Elevation Changes ◽

The Subject ◽

Geodetic Mass Balance

Abstract. Changes in the volume and extent of land ice of the Svalbard archipelago have been the subject of considerable research since their sensitivity to changes in climate was first noted. However, the measurement of these changes is often necessarily based on point or profile measurements which may not be representative if extrapolated to a whole catchment or region. Combining high-resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's surface without the need for extrapolation. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard archipelago spanning 1961 to 2005. We find high variability in thinning rates between sites with prevalent elevation changes at all sites averaging −0.59 ± 0.04 m a−1 between 1961–2005. Prior to 1990, ice surface elevation was changing at an average rate of −0.52 ± 0.09 m a−1 which decreased to −0.76 ± 0.10 m a−1 after 1990. Setting the elevation changes against the glaciers' altitude distribution reveals that significant increases in thinning rates are occurring most notably in the glaciers' upper reaches. We find that these changes are coincident with a decrease in winter precipitation at the Longyearbyen meteorological station and could reflect a decrease in albedo or dynamic response to lower accumulation. Further work is required to understand fully the causes of this increase in thinning rates in the glaciers' upper reaches. If on-going and occurring elsewhere in the archipelago, these changes will have a significant effect on the region's future mass balance. Our results highlight the importance of understanding the climatological context of geodetic mass balance measurements and demonstrate the difficulty of using index glaciers to represent regional changes in areas of strong climatological gradients.

Evolution of Ossoue Glacier (French Pyrenees) since the end of the Little Ice Age

The Cryosphere ◽

10.5194/tc-9-1773-2015 ◽

2015 ◽

Vol 9 (5) ◽

pp. 1773-1795 ◽

Cited By ~ 20

Author(s):

R. Marti ◽

S. Gascoin ◽

T. Houet ◽

O. Ribière ◽

D. Laffly ◽

...

Keyword(s):

Mass Balance ◽

Little Ice Age ◽

Atlantic Multidecadal Oscillation ◽

Ablation Rate ◽

Ice Age ◽

Data Sets ◽

Climatic Data ◽

Geodetic Mass Balance ◽

Slight Growth ◽

Abstract. Little is known about the fluctuations of the Pyrenean glaciers. In this study, we reconstructed the evolution of Ossoue Glacier (42°46' N, 0.45 km2), which is located in the central Pyrenees, from the Little Ice Age (LIA) onwards. To do so, length, area, thickness, and mass changes in the glacier were generated from historical data sets, topographical surveys, glaciological measurements (2001–2013), a ground penetrating radar (GPR) survey (2006), and stereoscopic satellite images (2013). The glacier has receded considerably since the end of the LIA, losing 40 % of its length and 60 % of its area. Three periods of marked ice depletion were identified: 1850–1890, 1928–1950, and 1983–2013, as well as two short periods of stabilization: 1890–1894, 1905–1913, and a longer period of slight growth: 1950–1983; these agree with other Pyrenean glacier reconstructions (Maladeta, Coronas, Taillon glaciers). Pyrenean and Alpine glaciers exhibit similar multidecadal variations during the 20th century, with a stable period detected at the end of the 1970s and periods of ice depletion during the 1940s and since the 1980s. Ossoue Glacier fluctuations generally concur with climatic data (air temperature, precipitation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation). Geodetic mass balance over 1983–2013 was −1.04 ± 0.06 w.e.a−1 (−31.3 ± 1.9 m w.e.), whereas glaciological mass balance was −1.45 ± 0.85 m w.e. a−1 (−17.3 ± 2.9 m w.e.) over 2001–2013, resulting in a doubling of the ablation rate in the last decade. In 2013 the maximum ice thickness was 59 ± 10.3 m. Assuming that the current ablation rate remains constant, Ossoue Glacier will disappear midway through the 21st century.

Recent geodetic mass balance of Monte Tronador glaciers, northern Patagonian Andes

The Cryosphere ◽

10.5194/tc-11-619-2017 ◽

2017 ◽

Vol 11 (1) ◽

pp. 619-634 ◽

Cited By ~ 14

Author(s):

Lucas Ruiz ◽

Etienne Berthier ◽

Maximiliano Viale ◽

Pierre Pitte ◽

Mariano H. Masiokas

Keyword(s):

Mass Balance ◽

Dynamic Equilibrium ◽

Warm Season ◽

Glacier Mass Balance ◽

Mass Budget ◽

Mountain Glaciers ◽

Geodetic Mass Balance ◽

Elevation Model ◽

Patagonian Andes

Abstract. Glaciers in the northern Patagonian Andes (35–46° S) have shown a dramatic decline in area in the last decades. However, little is known about glacier mass balance changes in this region. This study presents a geodetic mass balance estimate of Monte Tronador (41.15° S; 71.88° W) glaciers by comparing a Pléiades digital elevation model (DEM) acquired in 2012 with the Shuttle Radar Topography Mission (SRTM) X-band DEM acquired in 2000. We find a slightly negative Monte-Tronador-wide mass budget of −0.17 m w.e. a−1 (ranging from −0.54 to 0.14 m w.e. a−1 for individual glaciers) and a slightly negative trend in glacier extent (−0.16 % a−1) over the 2000–2012 period. With a few exceptions, debris-covered valley glaciers that descend below a bedrock cliff are losing mass at higher rates, while mountain glaciers with termini located above this cliff are closer to mass equilibrium. Climate variations over the last decades show a notable increase in warm season temperatures in the late 1970s but limited warming afterwards. These warmer conditions combined with an overall drying trend may explain the moderate ice mass loss observed at Monte Tronador. The almost balanced mass budget of mountain glaciers suggests that they are probably approaching a dynamic equilibrium with current (post-1977) climate, whereas the valley glaciers tongues will continue to retreat. The slightly negative overall mass budget of Monte Tronador glaciers contrasts with the highly negative mass balance estimates observed in the Patagonian ice fields further south.

Post−surge geometry and thermal structure of Hørbyebreen, central Spitsbergen

Polish Polar Research ◽

10.2478/popore-2013-0019 ◽

2013 ◽

Vol 34 (3) ◽

pp. 305-321 ◽

Cited By ~ 16

Author(s):

Jakub Małecki ◽

Samuel Faucherre ◽

Mateusz C. Strzelecki

Keyword(s):

Mass Balance ◽

Ground Penetrating Radar ◽

Considerable Increase ◽

Thermal Structure ◽

Radar Data ◽

Negative Mass ◽

Contour Lines ◽

Digital Elevation ◽

Geodetic Mass Balance ◽

Abstract Hørbyebreen surged in the 19th or early 20th century, as suggested by geomorphological evidences and looped medial moraines. In this study, we investigate its wide−spread geometry changes and geodetic mass balance with 1960 contour lines, 1990 and 2009 digital elevation models, in order to define the present−day state of the glacier. We also study its thermal structure from ground−penetrating radar data. Little is known about the glacier behaviour in the first part of the 20th century, but from its surge maximum until 1960 it has been retreating and losing its area. In the period 1960-1990, fast frontal thinning (2-3ma−1) and a slow mass build−up in the higher zones (~0.15 m a−1) have been noted, resulting in generally negative mass balance (−0.40 ± 0.07 m w. eq. a−1). In the last studied period 1990-2009, the glacier showed an acceleration of mass loss (−0.64 m ± 0.07 w. eq. a−1) and no build−up was observed anymore. We conclude that Hørbyebreen system under present climate will not surge anymore and relate this behaviour to a considerable increase in summer temperature on Svalbard after 1990. Radar soundings indicate that the studied glacial system is polythermal, with temperate ice below 100-130 m depth. It has therefore not (or not yet) switched to cold−bedded, as has been suggested in previous works for some small Svalbard surge−type glaciers in a negative mass balance mode.

Remote Sensing Investigation of the Offset Effect between Reservoir Impoundment and Glacier Meltwater Supply in Tibetan Highland Catchment

Water ◽

10.3390/w13091307 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1307

Author(s):

Jingying Zhu ◽

Chunqiao Song ◽

Linghong Ke ◽

Kai Liu ◽

Tan Chen

Keyword(s):

Remote Sensing ◽

Mass Balance ◽

Average Rate ◽

Glacier Mass Balance ◽

The Tibetan Plateau ◽

Joint Research ◽

Glacier Meltwater ◽

Reservoir Impoundment ◽

Lhasa River

This article presents multi-source remote sensing measurements to quantify the water impoundment and regulation of the Zhikong Reservoir (ZKR) and Pangduo Reservoir (PDR), together with the estimation of the glacier mass balance to explore whether the increased glacier meltwater supply can buffer the influences of the reservoir impoundment to some degree in the Tibetan highland catchment. The ZKR and PDR are two reservoirs constructed on the upper Lhasa River that originate from the Nyainqentanglha glaciers in the remote headwater in the Tibetan Plateau (TP) and lacks historical in situ hydrological observations in the long term. Therefore, the Joint Research Center (JRC) Global Surface Water dataset (GSW), and the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) data were used for estimating the total amount of water storage of the two reservoirs, and the SRTM and TanDEM-X DEMs were used for estimating the glacier mass balance. The result shows that the total amount of water impounded by reservoirs is 0.76 Gt, roughly 54% of their design capacities. The mass balance of the glaciers is estimated by comparing the elevation changes between the SRTM and TanDEM-X DEMs. The glaciers in this region melt at an average rate of 0.09 ± 0.02 Gt·year−1 from 2000 to circa 2013, and the impounded water of these reservoirs is comparable to the amount of glacier-fed meltwater in eight years.

Reconstruction of historical surface mass balance, 1984–2017 from GreenTrACS multi-offset ground-penetrating radar

Journal of Glaciology ◽

10.1017/jog.2020.91 ◽

2020 ◽

pp. 1-10

Author(s):

Tate G. Meehan ◽

H. P. Marshall ◽

John H. Bradford ◽

Robert L. Hawley ◽

Thomas B. Overly ◽

...

Keyword(s):

Mass Balance ◽

Ground Penetrating Radar ◽

Greenland Ice Sheet ◽

Snow Accumulation ◽

Surface Mass Balance ◽

Snow Density ◽

Surface Mass ◽

Age Model ◽

Ground Penetrating ◽

Good Agreement

Abstract We present continuous estimates of snow and firn density, layer depth and accumulation from a multi-channel, multi-offset, ground-penetrating radar traverse. Our method uses the electromagnetic velocity, estimated from waveform travel-times measured at common-midpoints between sources and receivers. Previously, common-midpoint radar experiments on ice sheets have been limited to point observations. We completed radar velocity analysis in the upper ~2 m to estimate the surface and average snow density of the Greenland Ice Sheet. We parameterized the Herron and Langway (1980) firn density and age model using the radar-derived snow density, radar-derived surface mass balance (2015–2017) and reanalysis-derived temperature data. We applied structure-oriented filtering to the radar image along constant age horizons and increased the depth at which horizons could be reliably interpreted. We reconstructed the historical instantaneous surface mass balance, which we averaged into annual and multidecadal products along a 78 km traverse for the period 1984–2017. We found good agreement between our physically constrained parameterization and a firn core collected from the dry snow accumulation zone, and gained insights into the spatial correlation of surface snow density.

Long-range terrestrial laser scanning measurements of annual and intra-annual mass balances for Urumqi Glacier No. 1, eastern Tien Shan, China

The Cryosphere ◽

10.5194/tc-13-2361-2019 ◽

2019 ◽

Vol 13 (9) ◽

pp. 2361-2383 ◽

Cited By ~ 8

Author(s):

Chunhai Xu ◽

Zhongqin Li ◽

Huilin Li ◽

Feiteng Wang ◽

Ping Zhou

Keyword(s):

Mass Balance ◽

Long Range ◽

Tien Shan ◽

Glacier Mass Balance ◽

Surface Mass Balance ◽

Mass Balances ◽

Surface Mass ◽

Mass Conversion ◽

Geodetic Mass Balance

Abstract. The direct glaciological method provides in situ observations of annual or seasonal surface mass balance, but can only be implemented through a succession of intensive in situ measurements of field networks of stakes and snow pits. This has contributed to glacier surface mass-balance measurements being sparse and often discontinuous in the Tien Shan. Nevertheless, long-term glacier mass-balance measurements are the basis for understanding climate–glacier interactions and projecting future water availability for glacierized catchments in the Tien Shan. Riegl VZ®-6000 long-range terrestrial laser scanner (TLS), typically using class 3B laser beams, is exceptionally well suited for repeated glacier mapping, and thus determination of annual and seasonal geodetic mass balance. This paper introduces the applied TLS for monitoring summer and annual surface elevation and geodetic mass changes of Urumqi Glacier No. 1 as well as delineating accurate glacier boundaries for 2 consecutive mass-balance years (2015–2017), and discusses the potential of such technology in glaciological applications. Three-dimensional changes of ice and firn–snow bodies and the corresponding densities were considered for the volume-to-mass conversion. The glacier showed pronounced thinning and mass loss for the four investigated periods; glacier-wide geodetic mass balance in the mass-balance year 2015–2016 was slightly more negative than in 2016–2017. Statistical comparison shows that agreement between the glaciological and geodetic mass balances can be considered satisfactory, indicating that the TLS system yields accurate results and has the potential to monitor remote and inaccessible glacier areas where no glaciological measurements are available as the vertical velocity component of the glacier is negligible. For wide applications of the TLS in glaciology, we should use stable scan positions and in-situ-measured densities of snow–firn to establish volume-to-mass conversion.

An optimized method to calculate the geodetic mass balance of mountain glaciers

Journal of Glaciology ◽

10.1017/jog.2018.79 ◽

2018 ◽

Vol 64 (248) ◽

pp. 917-931 ◽

Cited By ~ 1

Author(s):

RUBÉN BASANTES-SERRANO ◽

ANTOINE RABATEL ◽

CHRISTIAN VINCENT ◽

PASCAL SIRGUEY

Keyword(s):

Spatial Variability ◽

Mass Balance ◽

Mean Difference ◽

Full Density ◽

Elevation Change ◽

Low Contrast ◽

Mountain Glaciers ◽

Elevation Changes ◽

Geodetic Mass Balance ◽

Similar Accuracy

ABSTRACTUnderstanding the effects of climate on glaciers requires precise estimates of ice volume change over several decades. This is achieved by the geodetic mass balance computed by two means: (1) the digital elevation model (DEM) comparison (SeqDEM) allows measurements over the entire glacier, however the low contrast over glacierized areas is an issue for the DEM generation through the photogrammetric techniques and (2) the profiling method (SePM) is a faster alternative but fails to capture the spatial variability of elevation changes. We present a new framework (SSD) that relies upon the spatial variability of the elevation change to densify a sampling network to optimize the surface-elevation change quantification. Our method was tested in two small glaciers over different periods. We conclude that the SePM overestimates the elevation change by ~20% with a mean difference of ~1.00 m (root mean square error (RMSE) = ~3.00 m) compared with results from the SeqDEM method. A variogram analysis of the elevation changes showed a mean difference of <0.10 m (RMSE = ~2.40 m) with SSD approach. A final assessment on the largest glacier in the French Alps confirms the high potential of our method to compute the geodetic mass balance, without going through the generation of a full-density DEM, but with a similar accuracy than the SeqDEM approach.