The author would like to express sincere thanks to Martha Raynolds, university of Alaska, Fairbanks, for valuable comments on the article, and special thanks to Murielle Anselmet, the Évettes Hut manager, for her welcome and the enjoyable stay in the Hut. The author is grateful to the reviewers for their advice on the paper and to Sylvain Jobard for the authorisation to use some of the figures.
1A geomorphosite is defined as a landform with particular and significant geomorphological attributes, which qualify it as a component of the patrimony of a territory (Panizza, 2001). Research has been mainly directed towards the need to specify some strict protocol to assess geomorphosites and to classify them according to various criteria such as economic, aesthetic, scientific and cultural (Pralong, 2005 ; Serrano and González-Trueba, 2005 ; Zouros, 2005 ; Reynard et al., 2007 ; Sellier, 2009). Cultural criteria suggest selection of geomorphosites which are noteworthy for the visitors at a site and for which public access should be developed. The problem is to define the views for the visitors and especially to identify what is known and seen by the observers as opposed to what is unknown and undistinguished within the landscape. This preliminary stage determines the aspects of the landscape for tourist optimisation and considers the different semantic interpretations of the landscape. About this, E. Reynard (2005) said that “most of the geomorpholigical landscapes have more than one value. These values differ with age and culture. In all process of analysis, protection and optimisation of geomorphosites, a double component, objective and subjective, has to be taken into account”. Using this approach, we surveyed visitors to the Évettes glacial cirque in Haute-Maurienne (northern French Alps). The goal was to learn how the mountain visitors perceive the glacial retreat in the landscape and to define existing sociocultural links with the landscape. The perception of glacial retreat is especially important in the context of changes in the high mountain environment. Glaciers in the European Alps have lost about 30 % to 40 % of their surface-area and about 50 % of their volume since the end of the Little Ice Age, i.e., since the mid-19th century (Zemp et al., 2006). The process of optimising glacier landscapes for visitors is important, especially within the current context of glacier withdrawal. However, in France, the development of a sense of landscape patrimony is far behind other countries in the Alpine area. N. Cayla (2009) counted interpretive trails on glaciers of the Alps : 11 in Austria, 8 each in Italy and Switzerland, and only 2 in France. Yet visitor perception of the evidence of the glacier in the landscape, the proglacial area, allows the recognition of glacial retreat. Thus, we assessed the knowledge of the moraine landscape as evidence of a recent glacial presence. Finally, we surveyed people’s knowledge of the moraine landscape richness regarding history, ecology and geomorphology.
2The study was conducted in the interior part of the French Alps, in the upper Maurienne Valley, close to the Italian border in the Haut Arc Mountains (fig. 1A). The geologic unit of the Arc’s valley slopes is composed of phyllitic shales associated with a formation of calcschists and marbles. The structural assemblage of quartzites and blackschistes are highly metalliferous which gives them a rusty brown patina (Fudral et al., 1994). The Évettes Cirque is located in the southern part of the peripheral area of the Vanoise National Park, within the limits the Bonneval-sur-Arc commune, Savoie. The Évettes Glacier extends from 2600 m to 3460 m a.s.l. The glacier is dominated by summits reaching over 3400 m a.s.l., the highest being Albaron (3637 m ; fig. 1B). The Évettes Glacier front has been retreating since the last culmination of the Little Ice Age, about 1860 (Vivian, 1960 and 1975 ; Edouard, 1994 ; Jobard, 2005 ; fig. 2). Currently the glacier has uncovered more than 2000 m of the length of the valley. The retreat of the glacier has exposed new land surfaces. A range of moraine landforms characterises the proglacial environments, including moraine belts associated with the glacier retreat (fig. 3) and also lateral moraines along the edge of the valley (fig. 1B). These recessional moraine forms allow one to see where the Évettes Glacier reached its maximum position before melting began. Streams of water running from the upper glacial basin have built outwash plains (fig. 3). Some channels have been abandoned and have been colonised by pioneer vegetation. A lake fed by glacial meltwater was formed around 1950 (Jobard, 2005). The area uncovered by glacier recession is clearly visible in the valley landscape thanks to the open panoramic view (fig. 1B). The easy accessibility of the Évettes cirque, 2 hours of easy walking, permits day visits for a large range of walkers. Finally, the hut situated at the mouth of the valley is commonly frequented, making it easy to find people for the statistical survey (fig. 1B).
Fig. 1 – Évettes Glacier location. A : Map ; B : Panoramic view of the Évettes Cirque (July 2007, M. Moreau).
Fig. 1 – Localisation du glacier des Évettes. A : Carte de localisation ; B : Panorama du cirque des Evettes (juillet 2007, M. Moreau).
1 : Évettes Cirque ; 2 : Vanoise National Park boundary ; 3 : border ; 4 : main town ; 5 : village.
1 : cirque des Évettes ; 2 : limite du parc National de la Vanoise ; 3 : frontière ; 4 : commune principale ; 5 : commune secondaire.
Fig. 2 – Ice-surfaces decrease of the Évettes glacier since the end of the Little Ice Age.
Fig. 2 – Évolution surfacique du glacier des Évettes depuis la fin du Petit Âge Glaciaire.
Jobard, 2005 ; reproduced with permission of the author.
Jobard, 2005 ; reproduit avec la permission de l’auteur.
Fig. 3 – Schematic cross-section of the glacier foreland from the Hut to the glacier ice front
Fig. 3 – Coupe schématique de la marge proglaciaire des Évettes depuis le refuge jusqu’au front du glacier.
1 : glacier ; 2 : bedrock. Deposits before the Little Ice Age : 3 : glaciolacustrine tills ; 4 : glacio-fluvial tills. Deposits since the end of the Little Ice Age : 5 : tills ; 6 : ridge moraines ; 7 : peatland. (Jobard, 2005 ; reproduced with permission of the author).
1 : glacier ; 2 : lit rocheux. Formations anté-Petit Âge Glaciaire : 3 : alluvions glacio-lacustres ; 4 : alluvions fluvio-glaciaires. Formations post-Petit Âge Glaciaire : 5 : tills ; 6 cordons morainiques ; 7 : tourbières (Jobard, 2005 ; reproduit avec la permission de l’auteur).
3Two survey sessions were conducted during the summers of 2006 and 2007, daily during the holiday period (end of June and July). The survey was done from the Évettes Hut using questionnaires. The questionnaires were completed facing the Évettes Cirque landscape, during the day, so that the answers could be based on direct landscape observations. The 36 questions were combined into three categories : i) the reasons why people were visiting the Évettes Cirque (goal of the visit, duration of stay, kind of activity) ; ii) the perception of changes in the high mountain landscape ; (iii) the perception of the deglaciated area and visitor knowledge of the moraine landscape. 128 people answered the statistical survey. The population was mainly male (64 %) and the main socioprofessional group was management [41 % ; (craftsman : 1.5 % ; professional : 3.9 % ; employee : 15.5 % ; worker : 3.9 % ; retired people, student, unemployed : 24 % ; mountain worker such as guide, tour leader or park ranger : 10 %)]. The average age was 44 years old. A majority of the people came every year to mountain areas (92 %) and many of them (47 %) had already visited the Évettes Cirque. 53 % were visiting the place for the first time. A majority of the visitors stayed for one night in the Hut (87 %). For the first time a statistical analysis characterised the main variables distinguishing the groups of people regarding their knowledge of the high mountains, landscape change and glacial retreat. Those variables were taken into acount in a multivariate analysis to simultaneously analyse all the variables. As CFA requires homogeneous data for processing, the quantitative variables were transformed into Boolean items. The resulting first three axes were able to explain the structure of the data, showing the relationships between visitors and the type of mountain recreation along the first axis ; to perceptions of glacial retreat along the second axis ; and to perceptions of the moraine area along the third axis.
4A first analysis of the results gives a summary of perceptions of the high mountain landscape and the way the moraine area was seen and perceived.
5The glacier : key landscape element of the high mountains. Glaciers hold an important place in high mountain perception. The glacier is indicated by 90 % of the people surveyed as the main feature of the high mountain landscape (fig. 4A). Other landscape components had lower scores because the choices differed among people. Summits are the second landscape component associated with the high mountains, with 60 % of answers, followed in third place by moraines (30 %). Thus perceptions of high mountains are strongly linked to glaciers and evidence they leave in the landscape (moraines). The stony attribute given to the high mountains was shown by the absence of meadow as a choice of a characteristic landscape element even if it was present on the slopes (fig. 4A). The importance of the glacier within the landscape also appears in the answers given to the questions about landscape changes. The idea of glacial retreat is known, in fact 82 % of the people said that the glacier is changing over time (fig. 4B). The main reasons put forward were climate warming (70 % of the people), and the consequences of human activity (42 % ; fig. 4C). The glacial retreat is associated with the recent past, in fact 48 % of the people thought that it occurred within the last 30 years (fig. 4D). The natural climatic history was not included as a reason for the glacial retreat. Only 20 % of the people linked the glacial recession to a time scale greater than 100 years (fig. 4D). Knowledge of the glacial retreat seems to be more a repetition of a view expressed by society, most probably from the media, than a personal interpretation of the landscape. Thus, when we asked people to estimate the distance of the retreat of the Évettes Glacier the answers varied and showed differences among visitors in quantifying the surface liberated from ice. 13 % of the people did not know or did not see that the glacier had retreated, 55 % of the responses indicated that people saw part of the area liberated by the glacier, and only 32 % of the people said that they saw all of the deglaciated area (fig. 5A). However those results should be qualified : among the group of people who said they saw all the area liberated by the glacier (32 %), only 18 % had in fact a good estimation of the retreat distance (more than 1500 m ; fig. 5B). The majority of the people underestimated the spatial retreat of the glacier, 66 % of the people thought that the glacial retreat was less than 1500 m whereas it is more than 2000 m (fig. 5B). Those results allow us to suppose that the claim that the glacier is retreating depends on preconceived ideas or some presuppositions but not on direct observations of the Évettes Cirque landscape by visitors. This is an expression of how difficult it is to see evidence of the earlier glacier positions in the landscape and to estimate the spatiotemporal scales of the glacial retreat.
Fig. 4 – Perception of the high mountain landscape and its changes.
Fig. 4 – Perception du paysage de la haute montagne et de ses changements.
A: Amont the items, which terms are more characterise the high mountain mandscape (3 choices)? X-axis, left to right : glacier, peak, moraine, firn, hut, crest line, cirque, col, scree, waterfall, lake, torrent, avalanche, meadow, forest. Y-axis : percentage of answers. B : Which elements of the landscape change through time ? X-axis, answers left to right : glacier, snow, rockfall, régional development, vegetation, moraine, runoff, animals, firn, lake, walking trail, I do not know other. Y-axis : percentage of answers. C : Which are the main causes of the changes (2 choices) ? X-axis, answers left to right : climate warming, human activity, natural changes, precipitation changes, tourist visits. Y-axis : percentage of answers. D : How long have these changes been happening ? X-axis, answers left to right : less than 30 years, 30 to 100 years, more than 100 years, I do not know. Y-axis : percentage of answers.
A : Parmi la liste des mots, citez les éléments paysagers caractéristiques de la haute montagne (3 maximum). Axe des abscisses, de gauche à droite : glacier, sommet, moraine, névé, refuge, ligne de crête, cirque, col, éboulis, cascade, lac, torrent, avalanche, pelouse, forêt. Axe des ordonnées : pourcentage de réponses. B : Citez les éléments du paysage de la haute montagne qui selon vous changent ? Axe des abscisses, de gauche à droite : glacier, neige, rocher/éboulis, aménagement anthropique, végétation, moraine, écoulement, animaux, névé, lac, chemin, je ne sais pas, autre. Axe des ordonnées : pourcentage de réponses. C : A quoi attribuez-vous les changements paysagers ? (deux choix possibles). Axe des abscisses, de gauche à droite : réchauffement du climat, activité humaine, naturelle, modifications des précipitations, fréquentation touristique. Axe des ordonnées : pourcentage de réponses. D : Depuis combien de temps ces changements paysagers opérent-ils ? Axe des abscisses, de gauche à droite : moins de 30 ans, entre 30 ans et 100 ans, plus de 100 ans, je ne sais pas. Axe des ordonnées : pourcentage de réponses.
Fig. 5 – Estimation of the Évettes glacier retreat.
Fig. 5 – Estimation du retrait du glacier des Évettes.
A: Do you see in the landscape the area occupied by the glacier before its retreat? X-axis, answers left to right : I do not know, no, partially, totally. Y-axis : percentage of answers. B : How far has the front of the Évettes Glacier retreated ? X-axis, answers left to right : less than 500 m, 500 m to 1500 m, more than 1500 m, I do not know. Y-axis : percentage of answers.
A : Identifiez-vous l’espace libéré par le glacier ? Axe des abscisses, de gauche à droite : je ne sais pas, non, partiellement, complétement. Axe des ordonnées : pourcentage de réponses. B : A combien de mètres estimez-vous le retrait du glacier ? Axe des abscisses, de gauche à droite : moins de 500 m, entre 500 m et 1500 m, plus de 1500 m, je ne sais pas. Axe des ordonnées : pourcentage de réponses.
6To introduce mountain visitors to the proglacial area. Knowledge of the moraine environment is relatively vague. “Moraine” was the best known word, and was indicated as landscape evidence of glacial retreat and as a new landscape form by 85 % of the people. But moraine is not used wisely. 30 % of the people chose other terms to point out moraine items (several answers were possible and some people used the word moraine and some other expressions ; fig. 6A). This was the case for expressions like : “rock on the glacier” and “color boundary”. The latter indicates the visual contrast between the moraine color (grey) and the neighbouring vegetation cover (green) and borderlines of the proglacial area. Resorting to those expressions instead of using the word moraine (or others) shows that people did not spontaneously use the term moraine for describing the landscape. This is also the case for the expression “roches moutonnées” that 30 % of the people said they knew (fig. 6B) but this expression was not used spontaneously and they used the term flagstone instead (fig. 6A). Finally the runoff was never linked to the glacier melting whereas the streams were especially visible in the landscape (fig. 1B). The proglacial landscape was poorly or approximately understood and the landscape perception of the deglaciated area was vague. Furthermore the moraine area is somewhat unpopular. Almost 50 % of the people considered the deglaciated area to have a little or no aesthetic value in the high mountain landscape, as opposed to 25 % who qualified the moraine as aesthetic to very aesthetic (fig. 6C). The proglacial environment could be introduced especially in the way of geomorphology as a way to understand the earlier positions of the glacier and the history of its retreat. To know how to distinguish each landscape component of the moraine area such as vallum, erratic rock, and chattermark is one of the keys to interpreting and understanding the landscape. Ecologic aspects can also be exploited. Indeed, 30 % of the people did not know if vegetation grew on the moraines. Plant colonisation is probably poorly known and the floristic stages which are connected with the periods of glacial retreat are an ecologic richness to be discovered.
Fig. 6 – Perception of the moraine landscape.
Fig. 6 – Perception du paysage morainique.
A: Which landscape elements allow you to see that the glacier is retreating (several answers possible)? X-axis, answers left to right : moraine, rock on the glacier, color limit, flagstone, lake, crevasse, I do not know (items indicated by repondents). Y-axis : percentage of answers. B : Which terms do you know ? X-axis, answers left to right : moraine, ice front, riegel, lateral moraine, erratic block, roches moutonnées, rock basin, proglacial area, vallum, sandur. Y-axis : percentage of answers. C : How do you rate the moraine landscape ? X-axis, answers left to right : not aesthetic, a little aesthetic, aesthetic, very aesthetic, indistinguishable, original. Y-axis : percentage of answers.
(A : les réponses indiquées correspondent aux mots utilisés par les personnes enquêtées). A : Quels sont les éléments du paysage qui vous permettent de voir que le glacier est en recul (plusieurs réponses possibles) ? Axe des abscisses, de gauche à droite : moraine, rocher sur glacier, limite de couleur, dalle, lac, crevasses, je ne sais pas. Axe des ordonnées : pourcentage de réponses. B : Parmi cette liste de mots, quels sont les termes que vous connaissez ? Axe des abscisses, de gauche à droite : moraine, front glaciaire, verrou, moraine latérale, bloc erratique, roche moutonnée, ombilic, marge proglaciaire, vallum, sandur. Axe des ordonnées : pourcentage de réponses. C : Comment percevez-vous l’espace déglacé par rapport au paysage de la haute montagne ? Axe des abscisses, de gauche à droite : pas esthétique, un peu esthétique, esthétique, très esthétique, identique, original. Axe des ordonnées: pourcentage de réponses.
7Glacial retreat perception and knowledge in relation with type of mountain recreation. The factor analysis revealed a strong relation between the type of mountain recreation and the perception of the glacial retreat. Two main groups can be distinguished : mountaineers and hikers, shown in the factor analysis along the first axis (fig. 7). The groups have different mountain activities and length of stay which impact their landscape interpretation. Within each group, individuals were distinguished by their level of knowledge of the landscape, shown by the second axis, and their perception of glacial retreat shown by the third axis (fig. 7). Finally four groups were distinguished and symbolised in the factor space by ellipses (fig. 7). Most hikers were women, young working people (less than 30 years old) and retired people. They came to the Évettes Cirque during the day for a walk and to view the panorama. The hikers group defined the high mountain landscape with what they saw during their walk to the Évettes Cirque : cirque, runoff (they had to cross a channel ; fig. 7), col, lake. Among the hikers, two groups of people were distinguished. The first group did not see the visual evidences of glacial retreat in the landscape and did not know if the Évettes Glacier was currently receding (fig. 7A). The second hiker group (fig. 7B) assumed that the landscape was changing but they did not know clearly what was changing. Their assertions about the glacial retreat probably reflected a media view and not their own observations about the landscape. The mountaineers were mostly men, management and aged around 50 years old. They came to the Évettes area to climb and for the glacier. The mountaineers stayed at least one night at the Hut. Mountaineers had a wide experience in the high mountains and had a good knowledge of this environment. Climbing defined their perception of the high mountain landscape and they characterised that landscape with words used for climbing : crest line, firn, talus, peak, moraine. They also had a good knowledge of moraine words : riegel, roches moutonnées, erratic block, moraine. Among the mountaineers, some differences existed about the perception of landscape change. One group (fig. 7C) was characterised by a good knowledge of the Évettes Cirque and high mountain vocabulary. But they did not see the landscape change precisely : in particular they underestimated the glacial retreat distance. In constrast, a second mountaineers group (fig. 7D) had a good estimation of the retreat of the Évettes Glacier in both historical and ecological respects : distance and time of the retreat steps, knowledge about geomorphology and vegetation. This group included the people with the longest time-stay in the Évettes Cirque, at least two nights. Knowledge of the Évettes Cirque and assessement of the glacial retreat is in good agreement with the length of stay at the site and the form of mountain recreation. There are differences between hikers (who just visit), and mountaineers (who stay) in their level of perception and abilities to interpret the landscape. The longer people stay, the better they know how to read and understand the landscape. This shows the desirability of guiding visitors in how to interpret landscapes in order to develop recognition and appreciation of the unknown landscape parts such as the moraine area.
Fig. 7 – Perception of glacial retreat in relation to the type of mountain recreation.
Fig. 7 – Les perceptions du retrait glaciaire selon la pratique de la montagne.
Variable captions: mountaineering – main reason for the Évettes visit; moraine – terms best characterising the high mountain landscape; rock bar – terms known. First axis corresponds to the type of mountain recreation (mountaineers on left, and hikers on the right) ; second axis corresponds to the concern about glacial retreat from low on the top, to high at the base ; third axis corresponds to the perception/feeling about the proglacial area from indistinct at the top of the axis to precise on the lower part.
Légende des variables : alpinisme – raison de la visite du site ; moraine - élément paysager caractéristique de la haute montagne ; verrou – termes que vous connaissez. L’axe 1 différencie les individus selon le type de pratique en montagne (à droite les randonneurs, à gauche les alpinistes). L’axe 2 distingue les individus selon le niveau d’appréhension du retrait glaciaire (partie supérieure, niveau faible à fort dans la partie inférieure). L’axe 3 oppose les individus selon la visulatisaiton qu’ils ont de l’espace proglaciaire dans le paysage (partie supérieure, indistinct, à précis dans la partie inférieure).
8The results of the statistical survey showed that although the glacial retreat is known it is often not seen in the landscape. Research is being conducted in the process of optimisation of the proglacial geomorphosite in order to identify glacier evidence in the landscape. N. Cayla (2009) indicated that tourist development of the proglacial area could be a way to stimulate the tourism attraction of the vulnerable area resulting from glacial rereat. In fact, as shown by the statistical survey results, the glacier has an important place within the social portrayal of the high mountain landscape due to its beauty, by being an emblem of the altitude, and as it is conveyed by literature, advertising and in the media through the public’s imagination of the mountains. Will the disappearance of glaciers have some effect on the number of people going to high mountain areas ? D. Scott et al. (2007) examined how climate change may influence park tourism in the Rocky Mountain region (western North America). Glacier National Park (USA, Montana) has lost 115 of its 150 glaciers over the past century and scientists estimate that the remaining 35 glaciers will disappear within the next 30 years (Hall and Farge, 2003). Glacier National Park would lose its namesake and the very resource that defined it. This study showed a situation where the response of a whole mountainous area to global warming is known : the glacier patrimony is condemned. For Norwegian mountains, A. Nesje et al. (2008) showed, based on future climate scenarios, that about 98 % of the Norwegian glaciers are likely to disappear and that the glacier area may decreased by about 34 % by AD 2100. Another study in the French Alps predicted that the consequence of an increase in temperature of +3°C in 2100 (IPCC scenario) would lead to a rapid withdrawal with a total disappearance of the Saint-Sorlin Glacier by the year 2070 (Le Meur et al., 2007). In that context, it seems necessary to diversify summer tourism activies in order to develop the tourism attraction of the upper Alpine valleys.
9Hikers are a tourist group with a poor knowledge of glacial retreat and understanding of the high mountain landscape and, in this way, are an especially interesting potential tourist audience to sensitise to proglacial geomorphosites. The development of a sense of proglacial patrimony will present another type of recreation for mountaineers whose visits otherwise might decrease in the face of glacial retreat. In fact, among the responses of the mountaineers, 55 % said that the routes had changed and 27 % found the climb more difficult. The glacier shrinkage leads to changing climbing routes and makes it more difficult to avoid falling. If some glacier climbing routes cannot be done as a consequence of the changing glacier morphology, the high mountain economy could be impacted, including the nights in the Hut which are associated with climbing activities. In fact, 54 % of the people who spent a night in the Hut said they came for climbing. A possible decrease in the number of climbing routes would also have some consequences on the work of guides. 11 % of the people who came to the Évettes Cirque came with a mountain guide.
10In the face of glacier retreat, questions about the impact of summer tourism development in the high mountains and the economic consequences are growing. It seems especially important to anticipate a possible decrease in the number of tourists with a process for optimising tourism linked to the glaciers and their proglacial area as a geomorphosite through the glacial history and the geomorphology (proglacial dynamics, moraines). Also protection and optimisation of glacier foreland ecology could be linked to the way plants colonise deglaciated terrain. Previous research has shown that plant colonisation created plant species diversity different from that present in the neighbouring meadows (Matthews, 1992). In this way, the moraine locally increases plant species biodiversity (Moreau, 2001 ; Pech et al., 2007). But moraines are also fragile environments especially in the case of the Évettes proglacial area as its location, in the peripheral area of the Vanoise National Park, leads to more picking of vegetation because it is forbidden inside the limits of the park. For example, Génépy, Artemesia sp. (wormwood), which colonises the moraines, is used for making liqueur. This plant species could be vulnerable to picking.
11The geomorphological richness of proglacial areas is still poorly known. Paradoxically despite a lack of interpretive glacier trails in France, glaciers are popular and are sometimes the main reason for visiting high mountains, as is the case for the Évettes Cirque. Our research showed that mountain visitors do not resist learning about the landscape but that interpretation can only be done within both the time of the stay and the type of mountain recreation. The more intense the mountain recreation is, the better the landscape is known. The knowledge of the Évettes Cirque is associated with the length of stay : the longer the stay, the more the visitor has time to observe and understand the landscape. The limited perception of landscape changes by visitors opens up new possibilities for considering the information which needs to be acquired and the development of a sense of landscape patrimony for mountaineers and hikers. Especially regarding the history and the scale of glacial retreat, it is necessary to become aware of a dynamic beginning over 30 years ago, and to understand that global warming is not only a result of human activities but also a consequence of natural climate trends. Spatial dimensions of the glacial retreat could be approached by emphasising the geomorphological diversity of moraines such as lines from the earlier glacial front positions and the considerable size of the glacier (lateral moraine, erratic block, vallum). The dynamic aspect of the glacial retreat is less recognised by visitors. Finally, the ecological aspects of the proglacial environment could be exploited for tourist attraction. It is important to view the moraine landscape as an integrated patrimony and to protect the proglacial area as a recent and complex environment, ecologically rich and fragile, with evidence of a recent glacial presence and an ongoing history of dramatic change.