The behaviour of a Norwegian glacier-dammed lake, before, during and after drainage in 1957 is described. The evidence of former shoreline terraces is interpreted and possible drainage mechanisms are discussed.

As a result of an historical sketch of scientific activity on Mount Washington, New Hampshire, it is shown that the late-season snow-bed that annually forms in Tuckerman Ravine disappeared, on the average, during the first week in August for the period 1922–58 as compared with an average date of 11 August for the period 1878–1906. This appears to correspond to a rise in spring (April to May) and summer (June to September) mean temperatures of 0.9° F. (0.5° C.) for each season from 1872–87 to 1933–58. The snow-bed probably has persisted through only one ablation season during recent years, that of 1926, although some evidence exists that it may have lasted through an occasional summer during the early and middle nineteenth century.

The mechanical interaction between a glacier and subglacial sediment can be observed using an instrumented rod that we refer to as the UBC ploughmeter. For clast-rich sediments, the rate of collision between clasts and a rod dragged through these sediments should be related to the glacier sliding rate. By assuming that proglacial measurements of sediment granulometry represent the subglacial granulometry of Trapridge Glacier, Yukon Territory, Canada, we have used ploughmeter results to obtain an estimated sliding rate of ∼45 mm d−1, in good agreement with known rates. In addition, for a subglacial material treated as a solid-liquid dispersion having a linear viscous rheology, the force of collision experienced by the rod should be proportional to the effective sediment viscosity. Our estimate of ∼2.0 × 1010 Pa s agrees well with previously, derived values.

Sediment deposition on to snow overlying glacier ice occurs in a marginal zone extending 200–300 m up-glacier from the terminus of Sylgjujökull. Debris on ice above the marginal snow zone comes from debris-rich layers, and 85% of this debris falls between 1 and 4ϕ, the characteristic grain-size of volcanic ash within Icelandic glaciers. The ash is transported down-glacier as suspended load in melt-water streams at concentrations between 61 and 430 mg l−1, and loads from 0.2 to 32.7 g s−1. A diurnal hysteretic loop is present in the relationship between suspended sediment and discharge for one stream.

Supraglacial streams flow from relatively impermeable ice on to more permeable snow near the glacier terminus. As they move across the snow, stream discharge (up to 0.1 m3 s−1 on ice) is reduced and debris is re-sedimented as linear debris trains 1–3 cm thick and orientated orthogonal to the glacier margin. Since sediment deposition reduces the permeability of the snow substrate, the debris trains are successively extended across the snow cover at rates of up to 36.5 m d−1. If the debris is then let down on to glacier ice, linear dirt-cone assemblages may be produced. Re-sedimented debris trains are of little stratigraphic significance if deposited pro-glacially.

Analysis of sediment-laden ice accreted at the base of ice sheets provides useful information on subglacial conditions and processes that otherwise cannot be observed or are very difficult to observe. While sediment-laden accreted basal ice can be accessed directly at the terminus of alpine glaciers, the basal zone of ice sheets is only accessible by drilling. Small amounts of sediment in the ice have provided few or no problems for conventional ice-core drilling (Gow and others, 1979; Weis and others, 1997); however, the higher-sediment-content accreted ice beneath West Antarctic ice streams (Vogel and others, 2005) has not been recovered using the California Institute of Technology (Caltech) hot-water ice corer (Engelhardt and others, 2000).

Model-generated ice-thickness fields for the period 1961–80 are examined in the context of summertime sea-ice predictability in the Beaufort Sea. The correspondence between the modeled and observed fluctuations of ice-covered area is found to be quite good. Lag correlation coefficients based on departures from 20 year “normals” of the ice thicknesses show that the ice anomalies are persistent throughout the August–May period. However, because the thickness anomalies undergo large fluctuations during July and August, only a small amount of summertime predictability can be derived from the thickness data. The findings are consistent with the observational results of Rogers (1978), who found that summertime temperatures and wind directions accounted for much of the variability of Beaufort Sea ice during August and September.

A mathematical model is constructed for land glaciers with the thickness much less than the horizontal dimensions and radii of curvature of large bottom irregularities by means of the method of a thin boundary layer in dimensionless orthogonal coordinates. The dynamics are described by a statically determinate system of equations, so the solution for stresses is found. For the general non-isothermal case the interrelated velocity and temperature distributions are calculated by means of the iteration of solutions for velocity and for temperature. Temperature distribution is determined by a parabolic equation with a small parameter at the senior derivative. Its solution is reduced to the solution of a system of recurrent non-uniform differential equations of the first order by means of a series expansion of the small parameter. A relatively thin conducting boundary layer adjoins the upper and lower surfaces of a glacier, playing the role of a temperature damper in the ablation area. For ice divides, the statically indeterminate problem is solved, so the result for stresses depends on the temperature distribution.

The response of ice to applied stress on ice-sheet flow timescales is commonly described by a non-linear incompressible viscous fluid, for which the deviatoric stress has a quadratic relation in the strain rate with two response coefficient functions depending on two principal strain-rate invariants I2 and I3. Commonly, a coaxial (linear) relation between the deviatoric stress and strain rate, with dependence on one strain-rate invariant I2 in a stress formulation, equivalently dependence on one deviatoric stress invariant in a strain-rate formulation, is adopted. Glen's uni-axial stress experiments determined such a coaxial law for a strain-rate formulation. The criterion for both uni-axial and shear data to determine the same relation is determined. Here, we apply Steinemann's uni-axial stress and torsion data to determine the two stress response coefficients in a quadratic relation with dependence on a single invariant I2. There is a non-negligible quadratic term for some ranges of I2; that is, a coaxial relation with dependence on one invariant is not valid. The data does not, however, rule out a coaxial relation with dependence on two invariants.

Under idealized conditions, when pressurized water has access to all low-pressure areas at the glacier bed, a sliding instability exists at a critical pressure, pc, well below the overburden pressure, p0. The critical pressure is given by , where l is the wave length and a is the amplitude of a sinusoidal bedrock, and T is the basal shear stress. When the subglacial water pressure, pw, approaches this critical value, the area of ice-bed contact, △l, becomes very small and the pressure on the contact area becomes very large. This pressure is calculated from a force balance and the corresponding rate of compression is obtained using Glen’s flow law for ice. On the assumption that compression in the vicinity of the contact area occurs over a distance of the order of the size of this area, Δl, a deformational velocity is estimated. The resultant sliding velocity shows the expected instability at the critical water pressure. The dependency on other parameters, such as wavelength l and roughness a/l, was found to be the same as for sliding without bed separation.

A physics-based snow model has been calibrated using data collected at Halley Bay, Antarctica, during the International Geophysical Year. Variations in snow temperature and density are well-simulated using values for the model parameters within the range reported from other polar field experiments. The effect of uncertainty in the parameter values on the accuracy of the predictions is no greater than the effect of instrumental error in the input data. Thus, this model can be used with parameters determined a priori rather than by optimization. The model has been validated using an independent data set from Halley Bay and then used to estimate 10 m temperatures on the Antarctic Peninsula plateau over the last half-century.

We developed a novel laser melting sampler (LMS) for ice cores to measure the stable water isotope ratios (δ18O and δD) as temperature proxies at sub-centimeter depth resolutions. In this LMS system, a 2 mm diameter movable evacuation nozzle holds an optical fiber through which a laser beam irradiates the ice core. The movable nozzle intrudes into the ice core, the laser radiation meanwhile melts the ice cylindrically, and the meltwater is pumped away simultaneously through the same nozzle and transferred to a vial for analysis. To avoid isotopic fractionation of the ice through vaporization, the laser power is adjusted to ensure that the temperature of the meltwater is always kept well below its boiling point. A segment of a Dome Fuji shallow ice core (Antarctica), using the LMS, was then demonstrated to have been discretely sampled with a depth resolution as small as 3 mm: subsequent analysis of δ18O, δD, and deuterium excess (d) was consistent with results obtained by hand segmentation within measurement uncertainties. With system software to control sampling resolution, the LMS will enable us to identify temperature variations that may be detectable only at sub-centimeter resolutions in ice cores.

In the middle of last century, Agassiz, Tyndall and others showed that a glacier flowed faster at its centre than at its margin. Partly from experiments and partly from the assumption that it behaved like a river, it became generally accepted that it also flowed faster at the surface than lower down. This belief was held until ten or fifteen years ago although search through earlier literature shows that evidence was accumulating which might disprove this.

Temperatures were measured within the firn and ice of the upper reaches of the Seward Glacier (referred to in this paper as the “upper Seward Glacier”) to a depth of 204 ft. (62.2 m.) by means of thermohms and a Wheatstone bridge. Thermal boring proved a feasible means of penetrating this glacier. The winter’s chilled layer here develops a thickness of 40–50 ft. (12.2–15.2 m.) and attains temperatures of at least −13° C. Deterioration of the chilled Iayer is rapid and irregular in the final phase and is attributed largely to freezing of percolating melt water. Melt water exerts such a powerful influence on thermal regimen that bodies of firn in environments with mean annual temperatures below freezing may, nonetheless, be geophyaically temperate because of extensive warming by melt water in summer. In both 1948 and 1949, the annual chilled layer on the upper Seward Glacier disappeared within the first 10 days of July. The slow development and rapid deterioration of diurnal crusts on firn and the lag effects at depth reproduce in miniature the behavior of the annual chilled layer. On the basis of its thermal regimen the upper Seward Glacier is geophysically temperate.

Such pot-holes as are caused by glacial action are in the main not due to cascades of melt water falling direct to the glacier bed, but are formed by the subglacial stream when conditions are favourable.

These glaciers are in a district that was seldom visited before the great expansion of recreational tramping and mountaineering in New Zealand during the past twenty years, but the record extends back for eighty-five years. During this time the chief glaciers have receded considerably but irregularly, and for one of them the records indicate a vertical downwasting and thinning. Although this glacier shows no sign yet of recovery it is fed from the same snowfield as that which supplies another glacier descending west from the main divide and which may have begun to advance. An appreciable re-advance of the Franz Josef Glacier has already been given notice in the, Journal of Glaciology, and it may be that the steep gradients of the west-flowing glaciers of the Southern Alps enable them to respond to short-term climatic fluctuations, whereas the flatter east-flowing streams continue to shrink, in keeping with the world-wide trend.

The chemical composition of meltwater-draining Himalayan glacierized basins reflects the dominance of carbonic acid in weathering of silicate and carbonate minerals, yet the role of sulfuric acid-mediated reactions in the mineral weathering and ionic release is still unclear. Here, we present a long-term study (1992–2018) of chemical weathering characteristics of a precipitation-dominated glacierized basin (Dokriani glacier) of central Himalaya. By using new and reprocessed datasets of major ions from the glacial/subglacial zones of the glacier, we suggest that two-thirds of the dissolved load of the meltwater derives from sulfuric acid-mediated weathering of minerals and rocks. We observed a clear control of carbonic acid-mediated reactions in the early ablation periods, while sulfuric acid-mediated reactions dominate in peak and late ablation periods. The slopes and intercepts in best-fit regressions of [*Ca2+ + *Mg2+ vs *SO42− and HCO3−] and [HCO3− vs *SO42−] in meltwater were following the stoichiometric parameters of sulfide oxidation coupled to carbonate dissolution reactions. The glaciers of the central and western Himalaya are in good agreement with the present estimates. We contend that the bedrock lithology has limited or second-order effects over the ionic release from Himalayan glaciers and surmise that these patterns are broadly applicable to the other orogenic systems of the world.