Alaska Highway Research Articles

Permafrost Carbon: What soil science has to say about its distribution and fate

Permafrost Carbon: What soil science has to say about its distribution and fate

Debris Flow Chronology and Potential Hazard along the Alaska Highway in Southwest Yukon Territory

We studied 30 large debris fans along the Alaska Highway between the Alaska-Yukon boundary near Beaver Creek and the south end of Kluane Lake to document late Holocene and historic debris flow activity and to evaluate the hazard that debris flows pose to the highway and other infrastructure. We used dendrochronology and tephrochronology to date surfaces on the fans and to estimate debris flow recurrence. All of the fans are paraglacial landforms of largely latest Pleistocene and early Holocene age. Debris flows continued to occur, probably at a diminishing rate, during the middle and late Holocene, but have only left an irregular carapace of deposits on the early Holocene fans. The White River tephra, which is about 1,200 years old, occurs across the surface of most of the fans, indicating that few debris flows and floods have escaped existing channels of streams on the fans. We conclude that future debris flows, like those that have occurred on nine fans in the past few decades, will mostly be restricted to present stream crossings.

A geosystems approach to permafrost investigations for engineering applications, an example from a road stabilization experiment, Beaver Creek, Yukon, Canada

The Alaska Highway crosses numerous terrain units underlined by warm and ice-rich discontinuous permafrost highly susceptible to thermal degradation. For years, this infrastructure, which is essential to transportation in northwestern Canada and Alaska, has been showing signs of road damage induced by permafrost degradation. In 2008, Yukon Highways and Public Works, and its international collaborators, implemented a road experimental site near Beaver Creek (Yukon) to test mitigation techniques aiming to control permafrost degradation. Permafrost investigations were done accordingly to a geosystem approach based on the hypothesis that permafrost has a distinctive sensitivity to climate and terrain conditions at a local scale and that changes (dynamics) in the system must be integrated in the analysis to obtain a holistic understanding of permafrost conditions and consequences of potential changes through time. Therefore, permafrost assessment at BC-RES came along with other components assessment such as local climate, natural terrain and embankment conditions.Four main units identified were typically ice-rich, with the exception of one shallow sub-unit (2B) that was ice-poor, but which contained the top of inactive ice-wedges, and Unit 3 at depth. The extent of the syngenetic ice wedges was not encountered, but reached at least a depth of 10.7m. Units 1 and 2 (likely eolian periglacial deposits) were fine-grained soils characterized by a potential to liquefy, if soils thaw and maintain their natural moisture content, and to differential thaw-settlement. Unit 3 (likely interglacial deposit) was mainly made of peat, while Unit 4 (likely glacial deposit) was a diamicton with a fine-grained matrix containing abundant excess ice. Impact from road embankment was measured at many locations in permafrost below the infrastructure. Isothermal profile under the road and embankment subsidence, assessed from core-drilling combination with GPR and ground temperatures, reflected the thermal impact of embankment and its interaction with other geosystem components (e.g. snow, groundwater) on the underlying ice-rich cryostratigraphic units. Thaw depth below embankment sideslopes had mostly reached sub-unit 2B, exposing now excess ground ice from the underlying very ice-rich sub-unit 2C and ice wedge to melting. In this context, an increase in permafrost degradation is expected in the near future, regardless of the mitigation technique performance.Application of the geosystem approach for road infrastructure in permafrost regions was beneficial at the BC-RES to identify the comprehensive critical engineering conditions that should be considered at the infrastructure spatial scale for road sustainability through timescale of its life. This approach emphasized the importance of changes in properties and processes, including their variability and dynamic related to interactions within the system. Overall, engineering studies in permafrost regions, which are typically sensitive to changes in conditions, would clearly benefit from applications of the geosystem approach, which can be adapted to spatial and time scales of these studies.

Multi-decadal degradation and persistence of permafrost in the Alaska Highway corridor, northwest Canada

Changes in permafrost distribution in the southern discontinuous zone were evaluated by repeating a 1964 survey through part of the Alaska Highway corridor (56° N–61° N) in northwest Canada. A total of 55 sites from the original survey in northern British Columbia and southern Yukon were located using archival maps and photographs. Probing for frozen ground, manual excavations, air and ground temperature monitoring, borehole drilling and geophysical techniques were used to gather information on present-day permafrost and climatic conditions. Mean annual air temperatures have increased by 1.5–2.0 ° C since the mid-1970s and significant degradation of permafrost has occurred. Almost half of the permafrost sites along the entire transect which exhibited permafrost in 1964 do so no longer. This change is especially evident in the south where two-thirds of the formerly permafrost sites have thawed and the limit of permafrost appears to have shifted northward. The permafrost that persists is patchy, generally less than 15 m thick, has mean annual surface temperatures >0 ° C, mean ground temperatures between −0.5 and 0 ° C, is in peat or beneath a thick organic mat, and appears to have a thicker active layer than in 1964. Its persistence may relate to the latent heat requirements of thawing permafrost or to the large thermal offset of organic soils. The study demonstrates that degradation of permafrost has occurred in the margins of its distribution in the last few decades, a trend that is expected to continue as the climate warms.

Addressing historic environmental exposures along the Alaska Highway

BackgroundA World War II defense site at Northway, Alaska, was remediated in the 1990s, leaving complex questions regarding historic exposures to toxic waste. This article describes the context, methods, limitations and findings of the Northway Wild Food and Health Project (NWFHP).ObjectiveThe NWFHP comprised 2 pilot studies: the Northway Wild Food Study (NWFS), which investigated contaminants in locally prioritized traditional foods over time, and the Northway Health Study (NHS), which investigated locally suspected links between resource uses and health problems.DesignThis research employed mixed methods. The NWFS reviewed remedial documents and existing data. The NHS collected household information regarding resource uses and health conditions by questionnaire and interview. NHS data represent general (yes or no) personal knowledge that was often second hand. Retrospective cohort comparisons were made of the reported prevalence of 7 general health problems between groups based on their reported (yes or no) consumption of particular resources, for 3 data sets (existing, historic and combined) with a two-tailed Fisher's Exact Test in SAS (n=325 individuals in 83 households, 24 of which no longer exist).ResultsThe NWFS identified historic pathways of exposure to petroleum, pesticides, herbicides, chlorinated byproducts of disinfection and lead from resources that were consumed more frequently decades ago and are not retrospectively quantifiable. The NHS found complex patterns of association between reported resource uses and cancer and thyroid-, reproductive-, metabolic- and cardiac problems.ConclusionLack of detail regarding medical conditions, undocumented histories of exposure, time lapsed since the release of pollution and changes to health and health care over the same period make this exploratory research. Rather than demonstrate causation, these results document the legitimacy of local suspicions and warrant additional investigation. This article presents our findings, with discussion of limitations related to study design and limitations that are inherent to such research.

Climatic determinants of white spruce cone crops in the boreal forest of southwestern Yukon

White spruce ( Picea glauca (Moench) Voss) cone crops were measured from 1986 to 2011 in the Kluane region of southwestern Yukon to test the hypothesis that the size of cone crops could be predicted from spring and summer temperature and rainfall of years t, t – 1, and t – 2. We counted cones in the top 3 m of an average of 700 white spruce trees each year spread over 3–14 sites along 210 km of the Alaska Highway and the Haines Highway. We tested the conventional explanation for white spruce cone crops that implicates summer temperatures and rainfall in years t and t – 1 and rejected it, since it explained very little of the variation in our 26 years of data. We used exploratory data analysis with robust multiple regressions coupled with Akaike’s information criterion corrected (AICc) analysis to determine the best statistical model to predict the size of cone crops. We could statistically explain 54% of the variation in cone crops from July and August temperatures of years t – 1 and t – 2 and May precipitation of year t – 2. There was no indication of a periodicity in cone crops, and years of large cone crops were synchronous over the Kluane region with few exceptions. This is the first quantitative model developed for the prediction of white spruce cone crops in the Canadian boreal forest and has the surprising result that weather conditions 2 years prior to the cone crop are the most significant predictors.

Alaska's place in the West: from the last frontier to the last great wilderness

From Sarah Palin's surprising rise to political stardom to recurring environmental battles over oil drilling in the arctic and public works projects like the Bridge to Nowhere, the remote state of Alaska continues to occupy center stage in the national spotlight. Yet for most Americans the history of this sparsely populated region remains a vast unknown. Roxanne Willis takes readers behind common and simplistic representations of the state to explore the rich history and extreme diversity of a land that cannot easily be pigeonholed into typical American conceptions about place. Alaska's story is usually confined to regional history books, and in many American history texts, the state simply disappears after the Klondike gold rush. Willis's book marks the first comprehensive examination of Alaskan development schemes from 1890 to the present, connecting these plans to the changing priorities of American culture and politics. She examines competing definitions of Alaska--from a Last Frontier meant to be exploited to a Last Wilderness to be protected at all costs--and explains how the contemporary Alaskan landscape is a result of this ongoing struggle to define this mythic state's place in the American West. Willis focuses on five historic battles between environmentalists and developers: the Alaska Native reindeer herding industry, the New Deal homesteader program in the Matanuska Colony, the construction of the Alaska Highway, the political dispute over the Rampart Dam, and the ongoing struggles over the Trans-Alaska Pipeline. She presents these case histories in clear language that will engage general readers while using new historical analysis that will appeal to scholars of environmental history and the American West. The result is an effective introduction to the historical origins of current political conflicts in Alaska. Transcending the typical regional histories of the state, Willis's study shows how Alaska development schemes have affected the history of American development more broadly, with conclusions that will be useful to anyone interested in environment and development issues in America or the circumpolar North--including a consideration of Alaska as the new frontier in global climate change. By showing why Alaska continues to resonate in the American imagination, Willis's book situates the forty-ninth state within the environmental movement, within the definition of the American West, and within American culture as a whole.

Remote sensing and field‐based mapping of permafrost distribution along the Alaska Highway corridor, interior Alaska

AbstractWe employed an integrated approach that combined remote sensing techniques with field measurements to predict the presence/absence of near‐surface permafrost in a section of the Alaska Highway corridor. We investigated the correlative relationships among vegetation type, topography, moss thickness, tussock condition and near‐surface permafrost in the study area. Analysis of moss thickness and active‐layer depth in low‐lying plains (slope <8°) showed an inverse relationship in different vegetation classes. The maximum likelihood classification of remotely sensed data mapped 80% of the study area as covered with vegetation. We developed an empirical‐statistical (Binary Logistic Regression) model to establish the statistical relationship between surface variables and permafrost. The statistical relationships between the surface variables (vegetation, aspect and elevation classes) and permafrost were used within a spatial model to estimate the probability of permafrost presence at any given location (or pixel) in the study area. The statistical model yielded an overall classification accuracy of 80%. The spatial model mapped 62% of the total vegetated area as underlain by permafrost, including 99.5% of the scattered short spruce, 92.5% of the dense tall spruce, and 35.8% of the mixed spruce and deciduous vegetation classes. Comparison of our probabilistic permafrost map with an independently produced photo‐interpreted permafrost map showed 75% agreement for the continuously frozen class and very close agreement for the discontinuously frozen class. Copyright © 2010 John Wiley & Sons, Ltd.

Challenges and Accomplishments: A Celebration of the Arctic Institute of North America

IN THE 1930S, EXPLORER VILHJALMUR STEFANSSON, northern scientists (particularly geologists), and developers such as Gilbert LaBine recognized the strategic nature and economic potential of the Arctic regions. The Second World War brought this potential into focus with various projects, especially the Northeast and Northwest Staging Routes for air traffic, the Alaska Highway, and the Canol Pipeline from Norman Wells, as well as the weather stations and the voyage of the St. Roch through the Northwest Passage. In 1942, a group of Canadians held private discussions about how Canada could increase her administrative, scientific, and technical competence in the Arctic to match that of other Arctic nations, such as the Soviet Union. These discussions about Arctic competence and Canadian sovereignty took place against a backdrop of disinterest and ignorance shared by the Canadian government and the public. Through personal contact with the Canadian Trevor Lloyd, American military people and scientists became aware of these discussions: the military was preoccupied with the strategic importance of the Arctic, while the scientists were interested in preserving and making accessible “a remarkable collection of hitherto unassembled information,” bequeathing it to an institution at war’s end (Parkin, 1966:8). By March 1944, Canadian initiatives had led to the realization that some objectives could best be achieved by an international organization. Accordingly, in May 1944, nine Americans and eleven Canadians met in New York: though they were there as individuals, they included senior bureaucrats and university people on the Canadian side and scientists and government Arctic specialists on the American side. Individual relations between these people were important dynamics in the formative stages. Despite differing perspectives, they established a private binational organization, with room for Greenland and Newfoundland and Labrador, and appointed Raleigh Parkin as pro tem secretary. This meeting also stressed the need for a headquarters close to an important library and other facilities, with good access to the capital cities. After a vigorous debate, an American-sponsored motion selected Montreal, with its well-equipped university libraries. In September 1944, at Montreal, the proposal for the new institute was approved. Its board of governors would include not only scientists, but also members with broad experience in financial management and administration. The proposal identified a need for independent scientific research: basic general research, studies on the problems of Arctic living, and an examination of the Arctic’s relationship to the physical, social, and economic problems of the world. The new institute would strive to coordinate its research with other ongoing research and to cooperate with government bodies and other research institutes. Geophysicist Laurence Gould became acting director in 1944, and Lincoln Washburn replaced him in October 1945. Offices were established at McGill University and in December 1945, by Act of Parliament, the Arctic Institute of North America was chartered. Its stated purposes were the following:

Energetic costs of male reproduction in a scramble competition mating system

1. The assumption that the primary limitations on reproductive success differ between the sexes is inherent in traditional sexual selection theory. Although the energy that can be allocated to reproduction is assumed to be the main limitation to females, the ability to attract and defend oestrous females is assumed to be the primary limitation to males. 2. Estimates of the energetic costs of reproduction in male mammals are, however, limited and have largely been obtained from sexually dimorphic species exhibiting female defence mating systems. These studies often reveal that the energetic cost of male reproduction is similar to or even exceeds that of females, and therefore challenge long-held assumptions of inter-sexual reproductive limitations, but their generality is little known. 3. We coupled measurements of energy expenditure with detailed behavioural observations of reproductive male North American red squirrels (Tamiasciurus hudsonicus). This species displays minimal sexual dimorphism and exhibits a scramble competition mating system, under which sexual selection favours enhanced mate searching effort by males. 4. We conducted the study over 2 years characterized by a substantial variation in upcoming natural food availability and across two study populations that experienced either natural food abundance or an ad libitum food-supplementation to investigate the influence of resource availability on male reproductive energy expenditure. 5. Under natural conditions, mean energy expenditure of males across the 2 years was high, approximating that of females during lactation. Furthermore, in the anticipation of high upcoming natural food availability and resultant offspring survival, expenditure approximately doubled (from 290 +/- 7 to 579 +/- 73 kJ day(-1)). When current food availability (and consequently the density of receptive females) was experimentally elevated, males displayed the highest levels of energy expenditure we recorded (873 +/- 98 kJ day(-1)). 6. Our results provide compelling evidence that the energy available for reproductive allocation places a strong limitation on reproduction in male North American red squirrels and contribute to previous work suggesting that high and limiting energetic costs of male reproduction may be a general feature of mammalian reproduction.

Mushroom crops in relation to weather in the southwestern Yukon

Epigeous mushroom production in the boreal forest ecosystem varies dramatically from year to year. We tested the hypothesis that the aboveground production of epigeous mushrooms in the Kluane region, Yukon, could be predicted by summer rainfall. There is a single crop in this part of the boreal zone with maximum production during the first 2 weeks of August. We measured standing crops from 1993 to 2007 at 13 areas along 210 km of the Alaska Highway and Haines Road in the southwestern Yukon. Aboveground mushroom crops averaged 24 kg/ha wet weight but varied from 0.0 to 117 kg/ha over the 15 years of study, with a coefficient of variation among years of 143%. Epigeous mushroom production could be predicted from June rainfall of the current year and May rainfall of the year previous with R2 = 0.85. Part of the lack of a perfect fit to rainfall was due to the constraint that years of high mushroom crops could not be followed by another high year, no matter what the rainfall pattern. We were not able to identify the species of mushrooms in this study but we confirm from natural history observations that mushrooms are a critical food for several of the small mammal species in the Yukon boreal forest.

Range Extension of the Northern Long-eared Bat (Myotis septentrionalis) in the Yukon

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Building the Alaska Highway

Building the Alaska Highway

Science and the St Elias: an evolving framework for sustainability in North America's highest mountains

The past, present, and future contributions of science in the St Elias Mountains, and its relationship with regional development, resource management, and traditional ecological knowledge is examined. Science has evolved from an early foundation of exploration, through stages of resource inventories and surveys, to deductive scientific research and, more recently, a promising reconnection with traditional knowledge. Directly and indirectly, events such as the Klondike Gold Rush, construction of the Alaska Highway, creation of the Arctic Institute of North America's Kluane Lake Research Station, and establishment of protected areas have helped foster scientific activities in the region. In turn, this scientific perspective has influenced regional development by providing detailed information that has been utilized, to varying degrees, in resource use, planning, and decisionmaking. Over the past decade, management of the region has become less sectoral and more cooperative in nature, due partly to the implementation of co‐management agreements, regional land use planning, and settlement of first nations’ land claims. Incorporating both science and traditional knowledge into this process through collaborative endeavours such as long‐term ecological monitoring, adaptive management, and information integration will contribute to ecosystem‐based management of the St Elias and ensure that both perspectives play an integral role in sustainable development of the region.

The Use of Film as a Vehicle for Traditional Storytelling Forms

Abstract Introduction. One way storytelling and narrative heal is by helping families, communities, and even whole cultures develop and maintain a sense of who they are in the face of disruption, conflict, and change. Without this anchoring sense of identity, it is difficult to remain healthy in a rapidly changing world. The building of the Alaska Highway in the early 1940s was just such a disruptive experience for many First Nations people in the Yukon, and its legacy persists today. A foreshortened sense of the future and its possibilities is a common aftermath of traumatic experiences—and rapid cultural change can be traumatic. This presentation points out ways that narrative forms can help people who are caught in the turmoil of such change to rebuild a sense of identity and develop a more positive view of the future and its directions. Carol Geddes, a filmmaker from Teslin, Yukon, paraphrases Hopi storyteller Terry Tafoya when she talks about storytelling for these purposes as “a sacred and necessary responsibility.” As technology has changed, so have some aspects of storytelling, but the healing possibilities remain. In her film, Picturing a People: George Johnston, Tlingit Photographer, Geddes shows how she has adapted some of the traditional healing benefits of storytelling to a modern medium. At the same time Geddes’ presentation also makes a strong case for another, more traditional form of storytelling. In talking about how she came to make this film, Geddes tells her own personal story of finding her identity as a Native filmmaker. WHA

Intergenerational Differences in Ethnic Identification in a Northern Athapaskan Community

Introduction This paper is a first attempt to explore various features of ethnicity present in the aboriginal community of Upper Tanana Athapaskans of the Yukon-Alaska borderlands. In particular, I wish to focus on the presence and nature of intergenerational distinctions in identification. It is clear that there are differences between those people born after systematic state intervention in the region-from about 1960 onwards-and those whose lives include the period before this intervention. What is less clear is whether these differences are best accounted for by the increasing hegemony of the state or whether they are differences due to the age of the individuals within a locally constructed cultural life cycle. The concept of ethnicity that lam using here is based on understanding it as the social expression of group membership, which serves to maintain group identity, particularly in distinction with other groups, and the recognition that ethnic identities are neither ascribed nor achieved; they are both. They are wedged between situational selection and imperatives imposed from without (Ericksen 1993, 57). It is situational because ascriptive or proscriptive categories of ethnicity may vary with the particular social context in which it is applied (A. Cohen 1974). As a mode of consciousness, ethnicity is an emic-that is, from an insider's point of view-category of ascribed individual status, which is recognized and validated etically-from the outside-by proscriptive social action. Moerman's conclusions as to Who are the Lue? sum up this dual nature of ethnicity: One is Lue by virtue of believing and calling himself Lue and of acting in ways which validate his Lueness (1965, 1219). The Fieldwork Area I am principally working with people who speak or are descendants of speakers of the Athapaskan native language known as Upper Tanana, more specifically the dialect of Scottie Creek--a people who identify themselves as the Scottie Creek Dindeh. Today, most of these people live in Beaver Creek, Yukon, and Northway, Alaska, two Alaska Highway communities that lie astride the international border, about 130 kilometers distant from each other. Although members of this group can be found in many other communities within and outside this region, having moved for marriage or economic opportunity, they maintain a primary identification as Scottie Creek people. [1] Until one hundred years ago, these people were exclusively foragers. In this regard they shared much with their Athapaskan cognates within the western Subarctic. Their economic adaptation of hunting and gathering natural resources followed a seasonal round within an ecological region defined by a geographical watershed. They aggregated within semipermanent villages for labor-intensive economic and ritual activity, and dispersed as small extended families during times of resource scarcity. They traveled widely for the purposes of trade and establishing and maintaining consanguinal and affinal kin relations (McKennan 1959). Kin-based economic and ritual activity was promoted and regulated by clan membership bifurcated into moieties. This included prescriptive marriage and ritual relations between moieties, which were socially recognized through potlatch aggregations (Guedon 1974). [2] Political relations were egalitarian, with a strong emphasis on the authority and responsibility of the individual in determining and pursuing an appropriate choice of action (Ridington 1982,1983; Goulet 1998). Extensive oral traditions provided the ideological basis for many aspects of social life, as well as support to a naturalistic worldview that understood humans and nature to be bound by reciprocal ties. The interpretation of dreams, visions, and communications from animals informed decisionmaking, contextualized experience, and explained misfortune (Easton n.d.; Nelson 1983; Ridington 1968). The effects of the arrival of Europeans to the region were diffused along existing aboriginal exchange networks prior to their meeting. …

Long-Span Deep-Corrugated Structural Plate Arches with Encased-Concrete Composite Ribs

The design and construction of two long-span reinforced deep-corrugated structural plate arch culverts are described. The arch structures have maximum spans of 23.3 and 19.0 m. They were constructed on the Alaska Highway in northern British Columbia, Canada, during the fall of 1998. The 23.3-m-span arch is the largest of its kind in the world. Both structures are intermittently reinforced using a system of encased-concrete stiffeners. This system employs concrete pumped into the cavities formed by opposing deep-corrugated steel plates fitted with shear studs. The reinforcement for the 19.0-m structure was terminated at a location above the springline of the arch. The reinforcement for the 23.3-m-span arch extended to the top of the foundation. The arches were designed in accordance with the provisions of the Ontario Highway Bridge Design Code and the new Canadian Highway Bridge Design Code for Buried Structures. They were also reviewed using a nonlinear frame analysis (Structural Optimization Design and Analysis, or SODA) and a finite-element analysis (Nonlinear Soil-Structure Interaction Program, or NLSSIP). The deflected shapes of the two arches were monitored by instruments in the field during the construction and backfilling operation. The design results and field-measured deflections are evaluated.

In Situ Investigation of Liquefiable Gravels

A series of dynamic in situ penetration tests was performed in deep alluvial gravel deposits at Seward, Alaska, that were shaken and apparently liquefied by the March 27, 1964, Alaska earthquake. Both a U.S. standard penetration test split spoon and a larger-diameter drive sampler were used, and dynamic cone penetrometers of two sizes were also driven into the gravels near the mouth of the Resurrection River that had exhibited settlement and lateral spreading as a result of earthquake shaking. Two safety hammers were used [nominally 623 N (140 lb) and 1334 N (300 lb)], and the energy delivered with various hammer and penetrometer combinations was measured throughout all tests. Limited measurements of hammer velocity were also made by a radar system developed for that purpose to allow for kinetic energy determination. Soils recovered in the split spoon samplers were sent to the U.S. Army Engineer Waterways Experiment Station Soils Research Facility in Vicksburg, Mississippi, where they were evaluated for classification (gradation and index properties). The sampling and testing procedures used at the Seward site, as well as preliminary analysis of the various penetration test results, are summarized. Comparisons are made with penetration resistance measurements made by the Alaska Highway Department immediately after the 1964 earthquake. Results of this investigation will be adapted to guide future practice for in situ determination of liquefaction resistance in coarse alluvial soils.

The response (1958-1997) of permafrost and near-surface ground temperatures to forest fire, Takhini River valley, southern Yukon Territory

Forest fires in permafrost areas often modify ground surface conditions, causing deepening of the active layer and thawing of near-surface permafrost. Takhini River valley lies in the discontinuous permafrost zone of southern Yukon Territory. The valley floor is covered by glaciolacustrine deposits, which are locally ice rich. In 1958 extensive forest fires burned most of the vegetation and the soil organic horizon in the valley, but, 50 km west of Whitehorse, 1 km2 of spruce forest adjacent to the Alaska Highway escaped burning. Permafrost beneath this stand of trees is in equilibrium with surface conditions: the active layer is 1.4 m thick, the base of permafrost is at 18.5 m, the annual mean temperature at the top of permafrost (1.5 m) is -0.8°C, and the temperature gradient in permafrost is constant with depth. At burned sites nearby there has been little regeneration of forest vegetation since the fire, and long-term permafrost degradation has occurred. At one burned site, the permafrost table is more than 3.75 m below the ground surface, the mean annual ground temperature is -0.2°C or warmer throughout the profile, the annual mean temperature at 1.5 m is 0.1°C, and permafrost is thawing from top and bottom. A simplified analytical model for thawing of permafrost indicates that over a millennium will be required to degrade permafrost completely at this site, if thawing proceeds from the top down. The result demonstrates the persistence of ice-rich permafrost a few metres below the ground surface, even at sites near the southern margin of permafrost in Canada.

Raison d'Étre

... Sometimes, amidst the rush and complexity of what passes for academic life in the last years of the second millennium, we miss the opportunity to reflect quietly on the reasons why we do what we do. This commentary is being written in the boardroom/poster room of the Arctic Institute's Kluane Lake Research Station in the Yukon. All around me on the walls are poster displays on such topics as the University of Ottawa Field School Program from 1975 to 1998, How Do Glaciers Surge?, Vertebrate Community Dynamics in the Yukon Boreal Forest, and the Mount Logan Ice Core Climatic Change Project. These displays focus on past and current projects at the research station, and are pinned up to explain to this season's field school students, graduate student researchers, and the occasional inquisitive tourist just what the Arctic Institute does in its 37th year of logistical support to Yukon science. ... when I met with my colleagues on the Kluane Lake Research Station Users' Committee, we talked of our obligation to submit a Major Facilities Access Grant application to NSERC by October 1 to ensure that all of this tradition, science, and exuberant discovery can continue. Amidst a general air of good-humoured collaboration, social, biological, and physical scientists reviewed their progress over the past year and talked of their research dreams for the future. While the works conveyed strong commitment and rigor in the cause, the faces shone with the excitement of another good field season, renewed Yukon friendships, and the joy of sharing learning in one of the most beautiful places on earth. ... Behind the kitchen counter, ... I spied my 16-year-old son Lance washing dishes as a summer volunteer. ... Yesterday he told me that Andy Williams, the base manager, had taken him up in his Helio-Courier airplane to see the Icefield Ranges from 10,000 feet, and that it had been "one of the best things I've ever done in my life." ... As we cruise down the Alaska Highway back to the land of e-mail, appointment books, and commercial pleasures, we'll both know one thing: we'll be back.