. Norway and New Zealand both experienced recent glacial advances, commencing in the early 1980s and ceasing around 2000, which were more extensive than any other since the end of the Little Ice Age. Common to both countries, the positive glacier balances are associated with an increase in the strength of westerly atmospheric circulation which brought increased precipitation. In Norway, the changes are also associated with lower ablation season temperatures. In New Zealand, where the positive balances were distributed uniformly throughout the Southern Alps, the period of increased mass balance was coincident with a change in the Interdecadal Pacific Oscillation and an associated increase in El Niño/Southern Oscillation events. In Norway, the positive balances occurred across a strong west‐east gradient with no balance increases to the continental glaciers of Scandinavia. The Norwegian advances are linked to strongly positive North Atlantic Oscillation events which caused an overall increase of precipitation in the winter accumulation season and a general shift of maximum precipitation from autumn towards winter. These cases both show the influence of atmospheric circulation on maritime glaciers.

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Matthews, J. A. & Winkler, S. 2010: Schmidt‐hammer exposure‐age dating (SHD): application to early Holocene moraines and a reappraisal of the reliability of terrestrial cosmogenic‐nuclide dating (TCND) at Austanbotnbreen, Jotunheimen, Norway. Boreas, 10.1111/j.1502‐3885.2010.00178.x. ISSN 0300‐9483. Schmidt‐hammer exposure‐age dating (SHD) and terrestrial cosmogenic‐nuclide dating (TCND) are complementary techniques that can be used for mutual testing. SHD is low‐cost but requires local control points of known age and may be affected by local geological variation and other environmental factors that influence weathering rates. TCND is vulnerable to the occurrence of anomalous boulders, other geomorphological uncertainties and the effects of snow‐shielding at high altitudes. Both techniques are sensitive to post‐depositional disturbances if other than solid bedrock is sampled. SHD was applied to two moraine ridges beyond the Little Ice Age limit of Austanbotnbreen in the Hurrungane massif, southern Norway. Independent regional and experimental local age‐calibration curves were used to reappraise previous TCND results. Neither the two boulder surfaces nor their proximal bedrock surfaces could be differentiated statistically in terms of SHD exposure ages or their mean R‐values (±95% confidence intervals), which ranged from 40.73±1.72 to 43.34±0.69. The best of the independent regional‐calibration curves produced SHD exposure ages of 9413±723 and 9304±602 years, which are consistent with moraine formation early (c. 10.2 ka) and late (c. 9.7 ka) within the late‐Preboreal Erdalen Event. The current precision of SHD, as reflected in 95% confidence intervals of ±500–900 years, enables rejection of a Finse Event (c. 8.2 ka) age for either moraine. Results are consistent with a retracted Austanbotnbreen between the Erdalen Event and the Little Ice Age, and a modified model of Neoglaciation.

The use of the Schmidt hammer for the relativeage dating of boulder and bedrock surfaces is outlined. Two examples of the application of the Schmidt hammer for the dating of Holocene moraines in Mt Cook National Park, Southern Alps, New Zealand, confirm the potential of this method. With this technique it is possible to differentiate between Holocene moraines of different age (especially those built up since c. 5000 yr BP). The results show partial differences to those obtained from other dating techniques in previous work.

The steep outlet glaciers of Jostedalsbreen, western Norway, are good examples of sensitively reacting maritime mountain glaciers. Their changes in length, frontal position and lower tongue's morphology during the past 20 years have been well documented. At first they experienced a strong frontal advance. After AD 2000 glacier behaviour was dominated by a strong frontal retreat, in some cases causing a separation of the lowermost glacier tongue. In this paper, the glacier length changes are presented both visually and numerically, supplemented by mass balance and meteorological data. The glacier behaviour is interpreted and its causes are discussed. Whereas the factors controlling the advance during the 1990s seem clear, the interpretation of the most recent retreat still leaves some uncertainties. The actual glacier front behaviour cannot fully be related to the mass balance data. Terminus response times and relations between individual mass balance and meteorological parameters have changed. Some hypotheses are given, including disturbance of the `normal' mass transfer and dynamical response of the glacier front because of excessive ablation on the lowermost glacier tongues and summer back melting. These findings underline the sensitivity of maritime glaciers to climate changes. The empirical findings need to be taken into account in the interpretation of recent glacier length changes and their future modelling.

This study provides the first attempt to combine terrestrial (in situ) cosmogenic nuclide (10Be) surface exposure dating with Schmidt hammer relative-age dating for the age estimation of Holocene moraines at Strauchon Glacier, Southern Alps, New Zealand. Numerous Schmidt hammer tests enable a multi-ridged lateral moraine system to be related to three late-Holocene ‘Little Ice Age’-type events. On the basis of cosmogenic 10Be ages, those events are dated to c. 2400, 1700, and 1100 years ago. Linear age-calibration curves are constructed in order to relate Schmidt hammer R-values to cosmogenic 10Be ages. The high explanation yielded reveals the causal link between both data sets. The potential of combining both methods in a ‘’multiproxy approach’ is discussed alongside possible future improvements. Terrestrial cosmogenic nuclide dating delivers absolute ages needed as fixed points for Schmidt hammer age-calibration curves. The Schmidt hammer technique can be used to crosscheck the boulder surfaces chosen for surface exposure dating by terrestrial cosmogenic nuclides. It should, therefore, reduce the number of samples necessary and costs.

2014. Age and origin of ice-cored moraines In Jotunheimen and Breheimen, Southern Norway: insights from Schmidt-Hammer exposure-age dating.ABSTRACT. High-precision Schmidt-hammer exposureage dating (SHD) is applied to ice-cored moraine-ridge complexes at three high-alpine glaciers in Jotunheimen and Breheimen, southern Norway. Local calibration curves were established using moraine ridges dating from the last 50 years and bedrock surfaces deglaciated ∼9700 years ago. SHD ages, with 95% statistical confidence intervals, ranged from 3920 ± 790 years to a negative (futuristic) age of -890 ± 580 years at Gråsubreen, 420 ± 700 to 260 ± 710 years at Vesle-Juvbreen and 2250 ± 450 to 1605 ± 410 years at Østre Tundradalskyrkjabreen. Negatively skewed R-value distributions were interpreted as the result of weathered boulders from reworked surfaces. This leads to the interpretation of these SHD ages as maximum estimates of moraine-ridge age. Østrem's hypothesis (that the proximal ridges are the oldest and survived being overridden many times) is rejected on the basis of our SHD ages. Although ice-cored moraine ridges resemble the flow structures of rock glaciers, Barsch's hypothesis (that these icecored moraine complexes are rock glaciers) is also rejected. Instead, the ice-cored moraine-ridge complexes are considered to be glaciotectonic structures produced by the interaction of polythermal glaciers and alpine permafrost over the late Holocene. All the individual ridges were essentially formed during the 'Little Ice Age' glacier advance from material deposited earlier by multiple neoglacial events. The considerable size of the moraine complexes is attributed not only to the accumulation of material from these different events over a long period of time but also to their survival in the landscape during phases of glacier retreat when ice cores do not melt and fluvial and other destructive processes remain ineffective in the permafrost environment.

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