scholarly journals Glacier change of the Columbia Icefield, Canadian Rocky Mountains, 1919–2009

2013 ◽  
Vol 59 (216) ◽  
pp. 671-686 ◽  
Author(s):  
Christina Tennant ◽  
Brian Menounos
Keyword(s):  
Volume Change ◽  
Rocky Mountains ◽  
Relative Length ◽  
Aerial Photographs ◽  
Glacier Change ◽  
Volume Loss ◽  
Canadian Rocky Mountains ◽  
Elevation Change ◽  
Glacier Changes ◽  
Length And Area

AbstractWe determined length, area, elevation and volume change of the Columbia Icefield using Interprovincial Boundary Commission Survey maps from 1919, eight sets of aerial photographs from 1948 to 1993, and satellite data from 1999 to 2009. Over the period 1919–2009, glaciers on average retreated 1150 ± 34 m and shrank by 2.4 ± 0.2 km2. Total area loss was 59.6 ± 1.2 km2 (23 ± 5%), and mean elevation change was −49 ± 25 m w.e., resulting in a total volume loss of 14.3 ± 2.0 km3 w.e. Large outlet glaciers experienced the greatest absolute ice loss, while small, detached glaciers lost the most relative length and area. Thinning rates of debris-covered ice were 30–60% lower than those for clean ice. All glacier changes were significantly correlated with each other (p < 0.01), with r values ranging from 0.54 to 0.82. Temperature is correlated with length and area change over periods lagged 1–5 years (p < 0.05), and with elevation and volume change over periods lagged 9–18 years (p < 0.05). Precipitation is correlated with glacier change over periods lagged 1–10 years (p < 0.05).

scholarly journals Aldegondabreen glacier change since 1910 from structure-from-motion photogrammetry of archived terrestrial and aerial photographs: utility of a historic archive to obtain century-scale Svalbard glacier mass losses

2020 ◽  
pp. 1-10
Author(s):  
Erik Schytt Holmlund
Keyword(s):  
Loss Rate ◽  
Aerial Photographs ◽  
Volume Loss ◽  
Entire Study Period ◽  
Elevation Change ◽  
Entire Study ◽  
Mass Losses ◽  
Elevation Data ◽  
Manual Processing ◽  
Insight Into

Abstract Photogrammetric reconstructions of the Aldegondabreen glacier on Svalbard from 17 archival terrestrial oblique photographs taken in 1910 and 1911 reveal a past volume of 1373.7 ± 78.2 · 106 m3; almost five times greater than its volume in 2016. Comparisons to elevation data obtained from aerial and satellite imagery indicate a relatively unchanging volume loss rate of − 10.1 ± 1.6 · 106 m3 a−1 over the entire study period, while the rate of elevation change is increasing. At this rate of volume loss, the glacier may be almost non-existent within 30 years. If the changes of Aldegondabreen are regionally representative, it suggests that there was considerable ice loss over the entire 1900s for the low elevation glaciers of western Svalbard. The 1910/11 reconstruction was made from a few of the tens of thousands of archival terrestrial photographs from the early 1900s that cover most of Svalbard. Further analysis of this material would give insight into the recent history and future prospects of the archipelago's glaciers. Photogrammetric reconstructions of this kind of material require extensive manual processing to produce good results; for more extensive use of these archival imagery, a better processing workflow would be required.

scholarly journals Using structure from motion photogrammetry to measure past glacier changes from historic aerial photographs

2017 ◽  
Vol 63 (242) ◽  
pp. 1105-1118 ◽  
Author(s):  
LAUREN J. VARGO ◽  
BRIAN M. ANDERSON ◽  
HUW J. HORGAN ◽  
ANDREW N. MACKINTOSH ◽  
ANDREW M. LORREY ◽  
...  
Keyword(s):  
New Zealand ◽  
Mass Balance ◽  
Structure From Motion ◽  
Lower Cost ◽  
Aerial Photographs ◽  
Glacier Change ◽  
Climate Variability And Change ◽  
Glacier Changes ◽  
Camera Parameters ◽  
Remote Sensing Techniques

ABSTRACTQuantifying historic changes in glacier size and mass balance is important for understanding how the cryosphere responds to climate variability and change. Airborne photogrammetry enables glacier extent and equilibrium line altitudes (ELAs) to be monitored for more glaciers at lower cost than traditional mass-balance programs and other remote-sensing techniques. Since 1977, end-of-summer-snowlines, which are a proxy for annual ELAs, have been recorded for 50 glaciers in the Southern Alps of New Zealand using oblique aerial photographs. In this study, we use structure from motion photogrammetry to estimate the camera parameters, including position, for historic photographs, which we then use to measure glacier change. We apply this method to a small maritime New Zealand glacier (Brewster Glacier, 1670–2400 m a.s.l.) to derive annual ELA and length records between 1981 and 2017, and quantify the uncertainties associated with the method. Our length reconstruction shows largely continuous terminus retreat of 365 ± 12 m for Brewster Glacier since 1981. The ELA record, which compares well with glaciological mass-balance data measured between 2005 and 2015, shows pronounced interannual variability. Mean ELAs range from 1707 ± 6 to 2303 ± 5 m a.s.l., with the highest ELAs occurring in the last decade.

scholarly journals Rapid changes of Alpine glaciers in Austria tracked by ALS surveys 

2021 ◽  
Author(s):  
Kay Helfricht ◽  
Lea Hartl ◽  
Martin Stocker-Waldhuber ◽  
Bernd Seiser ◽  
Andrea Fischer
Keyword(s):  
Relative Volume ◽  
Surface Elevation ◽  
Ice Thickness ◽  
Mountain Range ◽  
Volume Loss ◽  
Elevation Change ◽  
Thickness Change ◽  
Alpine Glaciers ◽  
Glacier Changes ◽  
Surface Elevation Change

&lt;p&gt;Unprecedented glacier changes are reported for many mountain regions on earth based on surveys with different spatial resolution and repeat intervals. Eastern Alpine glaciers have been receding since the LIA maximum, with increasing relative volume loss at the beginning of the 21&lt;sup&gt;st&lt;/sup&gt; century. New high-resolution data of surface elevation from ALS surveys enable the analysis of most recent glacier changes at three mountain ranges in western Austria as an impact of climate change.&lt;/p&gt;&lt;p&gt;Surface elevation change rates between 2007 and 2018 increased again in comparison to former periods. Volume loss takes place even in the highest elevation zones, and most of the glaciers are out of an equilibrium state, such that consolidation of mass balance towards zero appears impossible under present climate conditions. The disintegration of low lying glacier tongues and a strong depletion of the firn cover are further signs of rapid glacier changes. The frequency distributions of surface elevation change throughout the area of each glacier show distinct shifts in peak ice thickness change and patterns of surface change distribution that suggest ongoing processes of glacier disintegration. Combining recent surface elevation changes and estimations of the spatial distribution of ice thickness in Austria shows that most of glaciers will vanish in 50 years or less. Only glaciers currently larger than 5 km&amp;#178; can be expected to exist longer at reduced size. At current rates of mass loss, glaciers are projected to retreat entirely to above 2800m in the &amp;#214;tztal and Stubai ranges by 2050. Further concerns arise regarding methods of tracking the future development of the remaining ice bodies. In particular, in the Silvretta mountain range, the majority of glacier margins have to be delineated in debris-covered glacier zones. It is debatable whether some of the smallest glaciogenic features should still be accounted for in glacier inventories or moved to an inventory of transient cryogenic landforms.&lt;/p&gt;

scholarly journals Using aerial photography to study glacier changes in Norway

2002 ◽  
Vol 34 ◽  
pp. 343-348 ◽  
Author(s):  
Liss Marie Andreassen ◽  
Hallgeir Elvehøy ◽  
Bjarne Kjøllmoen
Keyword(s):  
Aerial Photography ◽  
Traditional Method ◽  
Aerial Photographs ◽  
Multiple Models ◽  
Volume Loss ◽  
Traditional Methods ◽  
Digital Terrain ◽  
Terrain Models ◽  
Glacier Changes ◽  
The 1960S

AbstractThe Norwegian Water Resources and Energy Administration has photographed glacial areas in Norway for several decades. Detailed maps or digital terrain models have been made for selected glaciers from vertical aerial photographs. Multiple models of seven glaciers have been used here to calculate glacier volume change during the time between mappings using the geodetic method. Analyses and results are presented and compared with traditional mass-balance measurements. We estimated uncertainties of ±1.3–2.7mw.e. for the geodetic method, and ±1.3 –3.5mw.e. for the traditional method. The discrepancies between the methods varied between 0.4 and 4.7 mw.e. All glaciers decreased in volume from the 1960s/70s to the 1990s, except Hardangerjøkulen. This glacier experienced a significant increase in volume: the geodetic and traditional methods showed net balance values of +6.8m and +9.4mw.e., respectively. Trollbergdalsbreen had the largest total volume loss: the geodetic and traditional methods showed net balance values of –12.3 and –16.8mw.e.

scholarly journals The role of debris cover in the evolution of Zmuttgletscher, Switzerland, since the end of the Little Ice Age

2019 ◽  
Author(s):  
Nico Mölg ◽  
Tobias Bolch ◽  
Andrea Walter ◽  
Andreas Vieli
Keyword(s):  
Ice Age ◽  
Aerial Photographs ◽  
Volume Loss ◽  
Glacier Surface ◽  
Ablation Area ◽  
Slowing Down ◽  
Debris Cover ◽  
Historic Maps ◽  
Length And Area

Abstract. Debris-covered glaciers often exhibit large, flat tongues. Many of these glaciers show high thinning rates today despite thick debris cover. Due to lack of observations, most existing studies have neglected the dynamic interaction between debris cover and glacier evolution over longer time periods. The main aim of this study is to reveal this interaction by reconstructing changes of debris cover, glacier geometry, flow velocities, and surface features of Zmuttgletscher (Switzerland), based on historic maps, satellite images, aerial photographs, and field observations. We show that debris cover extent has increased from ~ 13 % to > 32 % of the total glacier surface since 1859 and that the debris is sufficiently thick to reduce ablation compared to bare ice over much of the ablation area. Despite the debris cover the volume loss of Zmuttgletscher is comparable to that of debris-free glaciers located in similar settings whereas changes in length and area have been small in comparison. Increased ice mass input in the 1970s and 1980s resulted in a temporary velocity increase, as well as a lowering of the upper margin of debris cover and exposed-ice area, and a reduction of ice cliffs. Since ~ 2001, the lowest ~ 1.5 km are stagnant despite a slight increase in surface slope of the glacier tongue. We conclude that the debris cover governs the pattern of volume loss without changing its magnitude, which is due to the large ablation area and strong thinning in regions with thin debris further up-glacier and in the regions of meltwater channels and ice cliffs. At the same time rising temperatures lead to increasing debris cover and decreasing glacier dynamics, thereby slowing down length and area losses.

scholarly journals Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2

2014 ◽  
Vol 8 (4) ◽  
pp. 1539-1559 ◽  
Author(s):  
V. Helm ◽  
A. Humbert ◽  
H. Miller
Keyword(s):  
Volume Change ◽  
Large Scale ◽  
Ice Sheets ◽  
Surface Elevation ◽  
Volume Loss ◽  
West Antarctica ◽  
Elevation Change ◽  
Time Period ◽  
Elevation Changes ◽  
Dronning Maud Land

Abstract. This study focuses on the present-day surface elevation of the Greenland and Antarctic ice sheets. Based on 3 years of CryoSat-2 data acquisition we derived new elevation models (DEMs) as well as elevation change maps and volume change estimates for both ice sheets. Here we present the new DEMs and their corresponding error maps. The accuracy of the derived DEMs for Greenland and Antarctica is similar to those of previous DEMs obtained by satellite-based laser and radar altimeters. Comparisons with ICESat data show that 80% of the CryoSat-2 DEMs have an uncertainty of less than 3 m ± 15 m. The surface elevation change rates between January 2011 and January 2014 are presented for both ice sheets. We compared our results to elevation change rates obtained from ICESat data covering the time period from 2003 to 2009. The comparison reveals that in West Antarctica the volume loss has increased by a factor of 3. It also shows an anomalous thickening in Dronning Maud Land, East Antarctica which represents a known large-scale accumulation event. This anomaly partly compensates for the observed increased volume loss of the Antarctic Peninsula and West Antarctica. For Greenland we find a volume loss increased by a factor of 2.5 compared to the ICESat period with large negative elevation changes concentrated at the west and southeast coasts. The combined volume change of Greenland and Antarctica for the observation period is estimated to be −503 ± 107 km3 yr−1. Greenland contributes nearly 75% to the total volume change with −375 ± 24 km3 yr−1.

Wildfires in the southern Canadian Rocky Mountains and their relationship to mid-tropospheric anomalies

1993 ◽  
Vol 23 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
E.A. Johnson ◽  
D.R. Wowchuk
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Large Scale ◽  
Fire Frequency ◽  
Fuel Moisture ◽  
Large Fire ◽  
Canadian Rocky Mountains ◽  
Area Burned ◽  
Upper Level ◽  
Moisture Conditions

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

Canadian Rocky Mountains

1903 ◽  
Vol 21 (6) ◽  
pp. 685
Author(s):  
J. Norman Collie
Keyword(s):  
Rocky Mountains ◽  
Canadian Rocky Mountains

Spatial and temporal variations of fire regimes in the Canadian Rocky Mountains and Foothills of southern Alberta

2016 ◽  
Vol 25 (11) ◽  
pp. 1117 ◽  
Author(s):  
Marie-Pierre Rogeau ◽  
Mike D. Flannigan ◽  
Brad C. Hawkes ◽  
Marc-André Parisien ◽  
Rick Arthur
Keyword(s):  
Rocky Mountains ◽  
Fire History ◽  
Fire Severity ◽  
Ecological Integrity ◽  
Fire Regimes ◽  
Temporal Variations ◽  
Fire Season ◽  
Canadian Rocky Mountains ◽  
Southern Alberta ◽  
Fire Exclusion

Like many fire-adapted ecosystems, decades of fire exclusion policy in the Rocky Mountains and Foothills natural regions of southern Alberta, Canada are raising concern over the loss of ecological integrity. Departure from historical conditions is evaluated using median fire return intervals (MdFRI) based on fire history data from the Subalpine (SUB), Montane (MT) and Upper Foothills (UF) natural subregions. Fire severity, seasonality and cause are also documented. Pre-1948 MdFRI ranged between 65 and 85 years in SUB, between 26 and 35 years in MT and was 39 years in UF. The fire exclusion era resulted in a critical departure of 197–223% in MT (MdFRI = 84–104 years). The departure in UF was 170% (MdFRI = 104 years), while regions of continuous fuels in SUB were departed by 129% (MdFRI = 149 years). The most rugged region of SUB is within its historical range of variation with a departure of 42% (MdFRI = 121 years). More mixed-severity burning took place in MT and UF. SUB and MT are in a lightning shadow pointing to a predominance of anthropogenic burning. A summer fire season prevails in SUB, but occurs from spring to fall elsewhere. These findings will assist in developing fire and forest management policies and adaptive strategies in the future.

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