Geological Survey of Canada Open File 8503 presents mass balance data from glaciers in the Cordillera Glacier-Climate Observing network for the 2015 and 2016 balance years. Glacier-wide net annual balances at all observing sites were negative for both years. Results from the surveys indicate warmer summer conditions with less winter accumulation occurred throughout western and northern Cordillera in 2015 compared to 2016. Where historical mass balance data exists, annual glacier-wide mass balances during both balance years were more negative than long-term averages. Historically significant melt rates were observed at Peyto Glacier where annual balance was 2nd most negative on record.

As a result of global climate change, glacial melt occurs worldwide. Major impacts are expected on the dynamics of aquifers and rivers in and downstream of mountain ranges. This study aims at quantifying the melt water input fluxes into the watersheds draining the Canadian Rocky Mountains and improving our knowledge about the fate of meltwater within the hydrological cycle. To this end, we use (1) time-variable gravity data from GRACE satellites that are decomposed into water storage compartments; (2) an ensemble of glacier information: in situ observations, geodetic measurements, and a mass balance model; and (3) in situ surface water and groundwater level observations. The glacier mass balance model estimates a total ice mass change of similar to 43 Gt for the period 2002-2015, corresponding to an average of -3,056 (+/- 2,275) MCM/yr (million cubic meters per year). 78% of the meltwater total flows west of the continental divide (to the Pacific Ocean), while 22% flows east of the continental divide (to the Arctic Ocean and Hudson Bay). However, the GRACE-derived total water storage increases, suggesting that groundwater storage compensates for the glacial melt with an increase of 3,976 (+/- 2,819) MCM/yr. A plausible explanation is that meltwater is not immediately flowing down in rivers but rather stored locally in aquifers. This hypothesis is supported by in situ river base flow observations, showing base flow increase in basins draining the ice melt, mostly west of the continental divide. Direct in situ evidences such as well water level time series are not sufficiently available to fully support this hypothesis. Plain Language Summary This study discusses glacial melt and its impacts on water resources in the Canadian Rocky Mountains. First, we quantify glacial melt inflows into the hydrological cycle flowing to the draining watersheds on both sides of the mountain range. Our melt estimation is in good agreement with previous studies. Second, we explore the fate of glacial meltwater, and in particular the changes occurring in aquifers, by comparing our melt estimates with other data sets such as geodetic gravity field time series and hydrometric data. While glacial mass change modeling estimates a relatively high mass loss for 2002-2015, geodetic observations show that groundwater storage has increased during the same period. Decreasing glacial mass is compensated by increasing groundwater mass in the total mass change derived from geodetic observation, suggesting water transfers from melting glaciers to aquifers. Field measurements support the hypothesis of a significant groundwater storage increase, but not enough field data are available to precisely and independently quantify this rise.

We show that the CryoSat-2 radar altimeter can provide useful estimates of surface elevation change on a variety of Arctic ice caps, on both monthly and yearly timescales. Changing conditions, however, can lead to a varying bias between the elevation estimated from the radar altimeter and the physical surface due to changes in the ratio of subsurface to surface backscatter. Under melting conditions the radar returns are predominantly from the surface so that if surface melt is extensive across the ice cap estimates of summer elevation loss can be made with the frequent coverage provided by CryoSat-2. For example, the average summer elevation decreases on the Barnes Ice Cap, Baffin Island, Canada were 2.05 ± 0.36 m (2011), 2.55 ± 0.32 m (2012), 1.38 ± 0.40 m (2013) and 1.44 ± 0.37 m (2014), losses which were not balanced by the winter snow accumulation. As winter-to-winter conditions were similar, the net elevation losses were 1.0 ± 0.20 m (winter 2010/11 to winter 2011/12), 1.39 ± 0.20 m (2011/12 to 2012/13) and 0.36 ± 0.20 m (2012/13 to 2013/14); for a total surface elevation loss of 2.75 ± 0.20 m over this 3-year period. In contrast, the uncertainty in height change from Devon Ice Cap, Canada, and Austfonna, Svalbard, can be up to twice as large because of the presence of firn and the possibility of a varying bias between the true surface and the detected elevation due to changing year-to-year conditions. Nevertheless, the surface elevation change estimates from CryoSat for both ice caps are consistent with field and meteorological measurements.

To answer questions about linkages between changes in glaciers and climate change—e.g., How much of the current global sea-level rise can be attributed to melting glaciers?—more precise and quantitative studies of glaciers are required. This includes systematically extending the available in situ and remote sensing data, putting together a more-detailed world glacier inventory (WGI), continuing and strategically enlarging the global mass balance monitoring network, and conducting a rigorous uncertainty assessment of the available data series.

Percussion coring systems rely on a moveable weight to push a core barrel into the sediment. The corer, attached to a cable, is lowered through the water column until it reaches the sediment. A second line is then used to raise then drop the weight on top of the core barrel. Over the years, several types of lightweight, percussion coring systems have been developed for use in remote locations where the weight of the equipment is a major concern. We used a Universal percussion corer to obtain sediment from lakes near the Jorge Montt Glacier in the Chilean Patagonia. Choosing a core sampling system was complicated by logistics: the remoteness of the field site and by the cumbersome nature of the equipment (including two small, inflatable boats) which had to be carried, on foot, over difficult terrain. We chose this particular corer as it is relatively inexpensive, lightweight, and easily assembled. It consists of a Universal core head (69 mm diam.), gravity weights, clear polycarbonate core barrels (120 cm and 240 cm long) and a slide hammer. We worked on shallow lakes (less than 5 m depth) from an unstable platform. However, this corer can be deployed in much deeper lakes. We could only recover short sediment cores because the lakes around Jorge Montt Glacier are very young. Nonetheless, we found this percussion core sampling system to perform well in the field but its full potential could not be assessed due to various particulars of the expedition.

(2009). Invited Commentary: A Framework for Integrated Research and Monitoring (FIRM) Canadian Water Resources Journal / Revue canadienne des ressources hydriques: Vol. 34, No. 1, pp. 1-6.

Although a great deal of research has focused on the hydrologic effects of climate variability and change, relatively little research has examined the effects on streamflow of interactions between climate variability and change and resulting glacier response. Place Glacier, in the southern Coast Mountains of British Columbia, Canada, has been monitored for mass balance since 1965, and a stream gauge was operated just below the glacier terminus from 1969 to 1989. This paper presents analyses of the mass balance history and streamflow variations in relation to recorded climatic variability.Place Glacier's winter and net balances are correlated with the Pacific Decadal Oscillation (PDO). Summer balance is positively correlated with summer temperature and negatively with the preceding winter balance, which enhances the effects of changes in winter balance on net balance. The well-documented post-1976 shift from the PDO cold phase to the present warm phase initiated a significant and persistent period of more negative net balance and terminal retreat. A reconstruction of net balance extending back to the 1890s, based on a regression with winter precipitation and summer temperature, displays decadal-scale fluctuations consistent with the PDO. Summer streamflow responded to interannual variations in winter snow accumulation and summer temperatures, which control the rate of rise of the glacier snowline and melt rates. After accounting for these influences via regression analysis, August streamflow displayed a negative trend in total runoff. Examination of air photographs and the reconstructed mass balance history suggest that significant firn depletion had occurred prior to 1965, such that the dominant effect of glacier changes was a reduction in ice area, resulting in decreased meltwater production. Copyright (C) 2001 John 'Wiley Sons, Ltd.

Baby Glacier, Axel Heiberg Island, N.W.T., Canada is a small (0.6 km(2)), high-latitude (79 degrees N), high-altitude (700-1200 m) glacier with a mass balance record extending from 1959-60 to the present. The record demonstrates shrinkage of the glacier, but a statistically significant trend is not evident. Correlations are strong between the mass balance of Baby Glacier and that of the nearby and much larger White Glacier, and also those of even larger, more distant glaciers. Thus programmes of measurement on small, simple ice bodies such as Baby Glacier can be representative of a large region. However, inter-annual changes are more accentuated for Baby Glacier. Baby Glacier does not meet all of the usual criteria for a representative glacier. but it straddles the regional equilibrium zone, a fact which helps to offset the disadvantages of its small size and limited altitudinal range. The equilibrium zone deserves to be an important focus for studies of high-arctic mass balance, with the aim of facilitating future measurement programmes which will rely on satellite remote sensing.

Flooding of deltas on large, northern rivers is usually the result of spring ice-jam events, as opposed to high flows during the open-water season. Some of the most sensitive components of such ecosystems are the perched basins: small ponds and lakes that are hydraulically isolated from the main flow system. The biological structure and productivity of these basins are highly dependent on flooding and flushing associated with high stage events. Major flooding of the Peace–Athabasca Delta, one of the world's largest and most productive deltas, has not occurred since 1974, the time of the last major ice-jam event. Prior to this, the Delta also experienced an extensive drying period, from 1968–1971, as one of its main rivers became regulated. As a result, extensive changes have occurred in the vegetation regime and associated wildlife habitat. Recognizing the historical role of ice-jam flooding, attempts are being made to induce flooding through regulation of the natural flow system using ice. The changing hydroecology of this flood-dependent ecosystem, common approaches related to regulation effects and river ice covers, and the unique strategies used to construct artificial ice dams and/or initiate ice jams, are all reviewed.

Delta ecosystems are often comprised of a myriad of channels and lakes, the latter of which can be subdivided according to the level of their connection with the main flow system. The dynamics of such lakes, in terms of their overall biological structure and productivity, depend on flooding and hushing during high-stage events. Major flooding of the Peace-Athabasca Delta-one of the world's largest and most productive deltas-has not occurred since 1974. Before this, the delta also experienced an extensive drying period from 1968 to 1971 as one of its main rivers became regulated. As a result, extensive changes have occurred in the vegetation regime and associated wildlife habitat. Two methods used in attempts to restore water to these systems are reviewed: rockfill weirs and artificial ice jams/dams. Recorded data since 1976 suggest that the weirs have been effective in restoring water on the large delta lakes to levels which would have occurred under an unregulated river regime. The weirs have not, however, replenished water in most of the perched basins. Moreover, even an historically high flow event in 1990 failed to flood them. Analysis of historical water level data revealed that ice-jam backwater is the only method by which these areas of the delta can be flooded. Although hydrometeorological conditions have not been conducive for the formation of major ice jams since 1974, attempts have been made to artificially induce an ice jam. The strategies, held trials and future applications of such an approach are reviewed.

This paper describes the spatial and temporal variability of strength in a typical river-ice cover during the pre-breakup period affected by radiation decay. Strength was determined using the borehole jack – a field-portable ice indentor system. Two cover types were analyzed: a granular white-ice/freeze-up jam and a columnar black-ice cover. Despite a protracted period of intense radiation, the strength of the highly-reflective ice in the freeze-up jam experienced no measurable change. The low-albedo, highly-transparent columnar cover, however, decreased in strength by approximately 50 % due primarily to the development of inter-granular void space. Changes are related to porosity and a comparison made to previous theoretical and laboratory work. Spatial variations in strength are discussed with respect to break-up advance and ice jamming. Possible control of break-up through modification of freeze-up processes is also presented.