Little Ice Age (LIA) moraines along the margins of Skálafellsjökull and Heinabergsjökull, two neighbouring outlet glaciers flowing from the Vatnajökull ice‐cap, have been re‐dated to test the reliability of different lichenometric approaches. During 2003, 12 000 lichens were measured on 40 moraine fragments at Skálafellsjökull and Heinabergsjökull to provide surface age proxies. The results are revealing. Depending on the chosen method of analysis, Skálafellsjökull either reached its LIA maximum in the early 19th century (population gradient) or the late 19th century (average of five largest lichens), whereas the LIA maximum of Heinabergsjökull occurred by the mid‐19th century (population gradient) or late‐19th century (average of 5 largest lichens). Discrepancies (c. 80 years for Skálafellsjökull and c. 40 years for Heinabergsjökull) suggest that the previously cited AD 1887 LIA maxima for both glaciers should be reassessed. Dates predicted by the lichen population gradient method appear to be the most appropriate, as mounting evidence from other geochronological reconstructions and sea‐ice records throughout Iceland tends to support an earlier LIA glacier maximum (late 18th to mid‐19th century) and probably reflects changes in the North Atlantic Oscillation. These revised chronologies shed further light on the precise timing of the Icelandic LIA glacier maximum, whilst improving our understanding of glacier‐climate interactions in the North Atlantic.

Glacier fluctuations from key Vatnajökull outlets have been redated using tephrochronology coupled with two lichenometric techniques to ascertain the timing of the Little Ice Age (LIA) maximum in southeast Iceland. An updated tephrochronology for southeast Iceland (both the number of tephra layers present and their geochemical signatures) indicates a LIA maximum for both glaciers between AD 1755 and 1873. Based on a population gradient approach, lichenometrically dated moraines along the margins of Skálafellsjökull and Heinabergsjökull narrow this window to the early to mid-19th century respectively. These revised chronologies, in addition to emerging evidence from elsewhere in Iceland, support a late 18th- to early 19th-century LIA glacier maximum. In contrast, the Norwegian LIA glacial maximum is strongly centred around AD1750. This implies differing glaciological responses to secular shifts in the North Atlantic Oscillation. Such revisions to the Vatnajökull record are crucial, as accurately identifying the timing and delimiting the spatial extent of the Icelandic LIA glacier maximum will allow further light to be shed on glacier–climate interactions in the North Atlantic.

A reassessed Little Ice Age chronology of the Franz Josef Glacier is presented. Diameter at breast height of 1340 southern rata (Metrosideros umbellata) and kamahi (Weinmannia racemosa) was measured within 50, 150-m 2 quadrats in the Waiho Valley. Age-size relationships based on 60 tree-ring counts and associated diameter at breast height measurements were constructed, although the unknown shape of growth curves beyond the realm of tree-ring data rendered extrapolation unreliable. Thus, the revised chronology is interpreted from mapped tree-ring counts and measured diameter at breast height of the largest rata and kamahi within moraine limits and trimlines to determine the minimum time elapsed since deglaciation.

Identifying moraine surfaces with similar histories using lichen size distributions and the U 2 statistic, southeast Iceland. Geogr. Ann., 90 A (2): 151-164.ABSTRACT. Moraine ridges are commonly used to identify past glacier ice margins and so infer glacier mass balance changes in response to climatic variability. However, differences in the form of past ice margins and post-depositional modification of moraine surfaces can complicate these geomorphic records. As a result, simple relationships, such as distance from current ice margin, or linear alignments, may not necessarily indicate moraines deposited contemporaneously. These disturbances can also modify the size distribution of lichen populations, providing a distinctive signature for surfaces with similar histories and a means of identifying contemporaneous moraine surfaces. In this paper, statistical analysis of lichen size distributions is used to identify moraine surfaces with similar histories from complex suites of Little Ice Age moraine fragments in the proglacial areas of Skálafellsjökull (including Sultartungnajökull) and Heinabergsjökull, southeast Iceland. The analysis is based on a novel use of the goodness-of-fit statistic, Watson's U 2 , which provides a measure of 'closeness' between two sample distributions. Moraine fragments with similar histories are identified using cluster analysis of the U 2 closeness values. The spatial pattern of the clustered moraines suggests three distinct phases of moraine deposition at Skálafellsjökull and Heinabergsjökull, four phases at Sultartungnajökull and a digitate planform margin at Heinabergsjökull. These spatial patterns are corroborated with tephrochronology. The success of the U 2 statistical analysis in identifying surfaces with similar histories using lichen size distributions suggests that the technique may be useful in augmenting lichenometric surface dating as well as differentiating between other surfaces that support lichen populations, such as rock avalanche deposits.

ABSTRACT. In Iceland, studies that integrate local perceptions about the landscape with scientific evidence of change have been few. This article presents a case study from southeast Iceland that has two main objectives. Firstly, ethnographic data is used to explore the human dimension of the Little Ice Age through perceptions of landscape and climatic change and to describe the impacts that these changes had on life and livelihood. Secondly, the paper critically assesses the coherence of the scientific record regarding the Little Ice Age glacial maximum with evidence gained from the ethnographic survey and the local historical record. Although climatic deterioration from the seventeenth through nineteenth centuries ultimately affected farming viability, it was the interplay of climate with concomitant cultural and socio-economic factors that ensured effective strategies were emplaced to preserve life and livelihood in southeast Iceland. Furthermore, despite different trajectories of perception emanating from either the scientific or the local points of view, data from all sources are strongly coherent and point to a Little Ice Age maximum during the late eighteenth to early nineteenth centuries. This study also illustrates that sensitive landscapes can 'store memories' through the cumulative accumulation of disturbances during periods of climatic variability, eventually reaching a critical threshold and inducing landscape instability, such as occurred during the nineteenth century.