Columbia Mountains Research Articles

The influence of fluvial and glacial watershed dynamics on Holocene sediment accumulation in Cariboo Lake, Columbia Mountains, British Columbia, Canada

Records of sedimentation collected from Cariboo Lake, situated in the northern Columbia Mountains, British Columbia, Canada, are analyzed to assess Holocene fluvial and glacial watershed dynamics. The aim of this study is to provide a proxy record of Holocene hydroclimate and glacier change from sediment archives at a higher temporal resolution compared to available records for the Interior Ranges of British Columbia. Deglacial and Holocene sediment accumulation is observed to reach a maximum thickness of 35 m in deep parts of the lake, using sub-bottom acoustic soundings. A transition from massive to well-stratified sediments is observed in the sub-bottom acoustic record during final phases of valley deglaciation in the region (~10.5–9 cal ka BP). Laminae couplets are interpreted to be deposited annually according to two 14C dates and a varve counting chronology. Two long cores, 2.9 and 3.8 m in length, were selected for analysis with estimated basal dates of 2 cal ka BP. Trends in downcore sediment characteristics were linked to environmental changes in the glaciated catchment headwaters at a temporal resolution of ~100 years. Upstream lake filtering of river floodplains and lakes prevented finding a higher temporal resolution linkage between the sediment characteristics and headwater fluvial and glacial activity. Despite some upstream filtering, the Cariboo River was found to be the primary source of sediment to the long core sites. Observed grain size and varve thickness from two long cores show above average trends, which are coincident with cooler temperatures and the primary glacier advances over the last 2 ka.

Recent changes in forest structure and growth at the alpine‐treeline ecotone in the Rocky and Columbia Mountains of central British Columbia, Canada

AbstractAimGlobally, forests at the alpine‐treeline ecotone (ATE) are considered sensitive to warming temperatures; however, responses to recent climate change show high variability and many underlying processes remain unclear. This study aims to provide further insight into possible ATE forest responses to climate change by examining spatiotemporal patterns in recent tree regeneration and growth responses to climate across treeline forms.LocationThis study is situated at the ATE in the Rocky Mountain and Columbia Mountain ranges in central British Columbia, Canada.TaxonGymnosperms – subalpine fir (Abies lasiocarpa Hooker (Nutall)).MethodsWe collected tree and stand data from 48 plots across five study sites. Plots were distributed across three treeline stand types: (i) islands; (ii) abrupt; and (iii) fringes of regeneration adjacent to tree islands. We used a dendrochronological approach to analyse the ages of recently established trees in fringe stand types, detect long‐term trends in annual tree growth and quantify climate‐growth relationships.ResultsSeedling recruitment adjacent to tree islands occurred over a period of approximately 40 years (1960–2000), with two regeneration “pulses” in the late 1970s and 1980s. Abrupt and fringe trees showed a similar age structure and annual radial growth has increased in most trees over the past 30 years. Across the study region and stand types, summer temperature has the strongest influence on radial growth. Over the past 70 years, growth in tree islands has become increasingly correlated with growing season temperature variables.Main ConclusionsForest growth and structure have changed in coherent spatial and temporal patterns over recent decades at the ATE in central BC. Projections for sustained warming in this region will likely result in increased tree growth and potential continued expansion of forests into untreed areas below the treeline. These changes will have implications for hydrological regimes, wildlife habitat and carbon sequestration.

Genomics of founders for conservation breeding: the Jasper caribou case.

The online version contains supplementary material available at 10.1007/s10592-023-01540-3.

Automated snow avalanche release area delineation in data-sparse, remote, and forested regions

Abstract. Potential avalanche release area (PRA) modeling is critical for generating automated avalanche terrain maps which provide low-cost, large-scale spatial representations of snow avalanche hazard for both infrastructure planning and recreational applications. Current methods are not applicable in mountainous terrain where high-resolution (≤5 m) elevation models are unavailable and do not include an efficient method to account for avalanche release in forested terrain. This research focuses on expanding an existing PRA model to better incorporate forested terrain using satellite imagery and presents a novel approach for validating the model using local expertise, thereby broadening its application to numerous mountain ranges worldwide. The study area of this research is a remote portion of the Columbia Mountains in southeastern British Columbia, Canada, which has no pre-existing high-resolution spatial datasets. Our research documents an open-source workflow to generate high-resolution digital elevation models (DEMs) and forest land cover datasets using optical satellite data processing. We validate the PRA model by collecting a polygon dataset of observed potential release areas from local guides, using a method which accounts for the uncertainty in human recollection and variability in avalanche release. The validation dataset allows us to perform a quantitative analysis of the PRA model accuracy and optimize the PRA model input parameters to the snowpack and terrain characteristics of our study area. Compared to the original PRA model our implementation of forested terrain and local optimization improved the percentage of validation polygons accurately modeled by 11.7 percentage points and reduced the number of validation polygons that were underestimated by 14.8 percentage points. Our methods demonstrate substantial improvement in the performance of the PRA model in forested terrain and provide means to generate the requisite input datasets and validation data to apply and evaluate the PRA model in vastly more mountainous regions worldwide than was previously possible.

Trichomycetes from the Columbia Mountains, British Columbia, Canada

Trichomycetes are a group of fungi and protists living in the guts of immature aquatic insects and other arthropods. The nature of this relationship is poorly understood but it is mostly described as obligately commensalistic, with the microbes exploiting a unique microhabitat. Collections of trichomycetes were made from freshwater insects in aquatic habitats near Castlegar in the Columbia Mountains, part of the Rocky Mountain Range in southeastern British Columbia. The collection sites were at altitudes ranging from 435 to 935 m and were made in July 2006. A total of 32 species were recorded including four new species, Harpella filispora sp. nov., Orphella columbiensis sp. nov., Smittium nodiradicatum sp. nov., and Smitium basiangustatum sp. nov. described here. These are the first records from Western Canada and two, Austrosmittium patagonicum and Glotzia distorta are new continental records. These findings are compared to reports from the western edge of the Rocky Mountain range near the Boise Mountains in Idaho and the Southern Rockies in Colorado.

Future Snow Changes over the Columbia Mountains, Canada, using a Distributed Snow Model

Future Snow Changes over the Columbia Mountains, Canada, using a Distributed Snow Model

Characterizing the Ectomycorrhizal Fungal Community of Whitebark Pine in Interior British Columbia: Mature Trees, Natural Regeneration and Planted Seedlings

Whitebark pine (Pinus albicaulis Engelm.; WBP) is an endangered subalpine tree species and requires associations with ectomycorrhizal fungi (ECMF) for survival and growth. Despite this obligate dependence, there are gaps in the identification of ECMF that associate with WBP. In addition, ECMF rarely feature in assessments of recovery actions and little is known about the relationship between ECMF and the insects and pathogens affecting WBP. We used next-generation sequencing to characterize ECMF occurring in soil and mycorrhizal root tip samples from naturally occurring mature WBP trees and seedlings as well as planted WBP seedlings in the Columbia Mountains of Interior British Columbia, Canada. ECMF data was paired with data on tree age, tree health and soil conditions. Thirty-three species and twenty-one genera of ECMF were identified with medium or high confidence from mycorrhizal root tip samples. Major groups were: generalist ascomycetes [Cenococcum, Meliniomyces (=Hyaloscypha)], Atheliales (Piloderma, Amphinema, Tylospora), non-ascomycetous generalists (e.g., Amphinema), associates of high-elevation conifers (species of Cortinarius, Russula) and Suilloids (Suillus, Rhizopogon). Differences in WBP ECMF with other, drier and southerly regions that have been studied previously, were consistent with a distinct forest type and an endemism hypothesis. Soil at the planting site and planted seedlings hosted a reduced ECMF community or were non-ectomycorrhizal, which can be explained by site factors and is expected to affect seedling survival. ECMF composition on mature trees was correlated with tree health, which may have implications for WBPs resistance to pathogens and signals that ECMF are affected by the decline of their host. Understanding the ecology of WBP ECMF and their relationship with tree performance is essential for WBP recovery efforts.

Surface Mass-Balance Gradients From Elevation and Ice Flux Data in the Columbia Basin, Canada

The mass-balance—elevation relation for a given glacier is required for many numerical models of ice flow. Direct measurements of this relation using remotely-sensed methods are complicated by ice dynamics, so observations are currently limited to glaciers where surface mass-balance measurements are routinely made. We test the viability of using the continuity equation to estimate annual surface mass balance between flux-gates in the absence of in situ measurements, on five glaciers in the Columbia Mountains of British Columbia, Canada. Repeat airborne laser scanning surveys of glacier surface elevation, ice penetrating radar surveys and publicly available maps of ice thickness are used to estimate changes in surface elevation and ice flux. We evaluate this approach by comparing modeled to observed mass balance. Modeled mass-balance gradients well-approximate those obtained from direct measurement of surface mass balance, with a mean difference of +6.6 ± 4%. Regressing modeled mass balance, equilibrium line altitudes are on average 15 m higher than satellite-observations of the transient snow line. Estimates of mass balance over flux bins compare less favorably than the gradients. Average mean error (+0.03 ± 0.07 m w.e.) between observed and modeled mass balance over flux bins is relatively small, yet mean absolute error (0.55 ± 0.18 m w.e.) and average modeled mass-balance uncertainty (0.57 m w.e.) are large. Mass conservation, assessed with glaciological data, is respected (when estimates are within 1σ uncertainties) for 84% of flux bins representing 86% of total glacier area. Uncertainty on ice velocity, especially for areas where surface velocity is low (<10 m a−1) contributes the greatest error in estimating ice flux. We find that using modeled ice thicknesses yields comparable modeled mass-balance gradients relative to using observations of ice thickness, but we caution against over-interpreting individual flux-bin mass balances due to large mass-balance residuals. Given the performance of modeled ice thickness and the increasing availability of ice velocity and surface topography data, we suggest that similar efforts to produce mass-balance gradients using modern high-resolution datasets are feasible on larger scales.

Bias-corrected estimates of glacier thickness in the Columbia River Basin, Canada

AbstractSeveral global datasets of glacier thickness exist, but the number of observations from western Canada are sparse and spatially biased. To supplement these limited observations, we measured ice thickness with ice penetrating radar on five glaciers in the Columbia Mountains, Canada. Our radar surveys, when combined with previous surveys for two glaciers in the Rocky Mountains, total 182 km of transects that represent 34 672 point measurements of ice thickness. Our measurements are, on average, 38% thicker than previous surface inversion model estimates of glacier thickness. Using our measurements within a cross-validation scheme, we model ice thickness with the Open Global Glacier Model (OGGM) driven with recent observations of surface mass balance and glacier elevation. We calibrated OGGM ice thickness by optimizing the ice creep parameter in the model. The optimized OGGM yields an ice volume for Columbia Basin of 122.5 ± 22.4 km3for the year 2000, which is 23% greater than the range of previous estimates. At current rates of glacier mass loss for this region, glaciers would disappear from the basin in about 65–80 years. Disappearance of these glaciers will negatively affect the basin's surface hydrology, freshwater availability and aquatic ecosystems.

Seasonal movements of White-tailed Deer (<i>Odocoileus virginianus</i>) in the Rocky Mountains of British Columbia

Nineteen adult female White-tailed Deer (Odocoileus virginianus), fitted with very high frequency or global positioning system collars in the Rocky Mountains of southeast British Columbia, exhibited straight-line seasonal movements ranging from <4 km to 109 km. Movement was almost entirely along the floor of both low- and high-elevation valleys, although there was some use of mid-elevation mountainsides during early winter. Spatial locations of deer spanned 891–2234 m above sea level. Seasonal movements of these deer from a single winter range extended to two provinces, three national parks, one provincial park, non-park provincial Crown land, and private land. Deer populations with similar movement patterns may be most effectively managed by considering their extensive movements and coordinating approaches across jurisdictions.

Satellite-Based Time Series of Chlorophyll in Chilko Lake, British Columbia, Canada

In Canada, many northern lakes are remote and difficult to access, with limited limnological data. Satellite sensors provide widespread coverage and growing time series of data unavailable via conventional sampling, but global validation is still limited. We evaluated chlorophyll estimates from the MERIS (Medium Resolution Imaging Spectrometer) sensor on board the European Space Agency (ESA) ENVISAT satellite for the ultra-oligotrophic Chilko Lake in the coastal mountains of central British Columbia. This lake supports a valuable sockeye salmon (Oncorhynchus nerka) population. We obtained good temporal coverage, through 1,425 scenes between June 18, 2002 and April 6, 2012. Although pre-processing was required to produce a high-quality dataset, one standard ESA algorithm generated chlorophyll estimates similar to field data. Regional and interannual phenological patterns were clear, and differences that may be important determinants of salmon production were well described. Although MERIS ceased operation in April 2012, it was replaced by the OLCI (Ocean and Land Color Instrument) on the SENTINEL 3a and 3b satellites launched in February 2016 and April 2018, respectively. We conclude that, with appropriate quality control and in situ validation, satellite-generated chlorophyll time series in sockeye salmon rearing lakes have significant potential as a fisheries planning and analysis tool.

Mechanisms influencing the winter distribution of wolverine Gulo gulo luscus in the southern Columbia Mountains, Canada

To better understand the mechanisms driving the distribution of a threatened carnivore, wolverine Gulo gulo, in the southern Columbia Mountains, we contrasted four hypotheses; climate, food, human disturbance and trapping harvest. We used non-invasive hair snagging methods to examine wolverine occupancy with respect to these factors, collectively and by sex, at a 5 km radius scale around sampling sites and at a larger 10 km radius to evaluate consistency over changes in scale. For all analyses our top models included food and human disturbance. Of the four food items examined; caribou Rangifer tarandus, mountain goat Oreamnos americanus, moose Alces alces and hoary marmot Marmota caligata, wolverine occurrence was most closely related to hoary marmot habitat. With regards to human disturbance, we documented a negative association with forestry road density and a positive association with protected areas. The importance of climate was low compared to the food and disturbance hypotheses. Somewhat surprisingly, recent harvest was positively associated with subsequent wolverine presence. Our top 10 km scale models were similar to the 5 km scale, but with a stronger positive link to caribou distribution. We show that marmot habitat is important to wolverine in winter and suggest that management actions for conservation prioritize factors related to female occurrence, as these were more clearly defined than male. We demonstrate that human disturbance is a major driver of wolverine distribution. Protected areas appear to be providing secure habitat, and reducing road density or mechanized use of roads in winter should be considered for species conservation. A positive spatial relationship with recent harvest, in the context of a heavily harvested population, suggests that harvest data alone may not be useful in detecting population declines.

The Cariboo Alpine Mesonet: sub-hourly hydrometeorological observations of British Columbia's Cariboo Mountains and surrounding area since 2006

Abstract. This article presents the development of a sub-hourly database of hydrometeorological conditions collected in British Columbia's (BC's) Cariboo Mountains and surrounding area extending from 2006 to present. The Cariboo Alpine Mesonet (CAMnet) forms a network of 11 active hydrometeorological stations positioned at strategic locations across mid- to high elevations of the Cariboo Mountains. This mountain region spans 44 150 km2, forming the northern extension of the Columbia Mountains. Deep fjord lakes along with old-growth western redcedar and hemlock forests reside in the lower valleys, montane forests of Engelmann spruce, lodgepole pine and subalpine fir permeate the mid-elevations, while alpine tundra, glaciers and several large ice fields cover the higher elevations. The automatic weather stations typically measure air and soil temperature, relative humidity, atmospheric pressure, wind speed and direction, rainfall and snow depth at 15 min intervals. Additional measurements at some stations include shortwave and longwave radiation, near-surface air, skin, snow, or water temperature, and soil moisture, among others. Details on deployment sites, the instrumentation used and its precision, the collection and quality control process are provided. Instructions on how to access the database at Zenodo, an online public data repository, are also furnished (https://doi.org/10.5281/zenodo.1195043). Information on some of the challenges and opportunities encountered in maintaining continuous and homogeneous time series of hydrometeorological variables and remote field sites is provided. The paper also summarizes ongoing plans to expand CAMnet to better monitor atmospheric conditions in BC's mountainous terrain, efforts to push data online in (near-)real time, availability of ancillary data and lessons learned thus far in developing this mesoscale network of hydrometeorological stations in the data-sparse Cariboo Mountains.

Ten Years of Monitoring Illustrates a Cascade of Effects of White Pine Blister Rust and Focuses Whitebark Pine Restoration in the Canadian Rocky and Columbia Mountains

Whitebark pine forests are declining due to infection by white pine blister rust and mountain pine beetle, combined with the effects of climate change and fire suppression. The Canadian Rocky and Columbia Mountains represent a large portion of the whitebark range; a vast area, exemplifying the need for knowledge about whitebark pine stands to target restoration. The aim of our work was to identify variables predicting live tree infection, seedling infection, canopy kill, mortality, and regeneration across this region, and present the results in spatially-explicit formats to assist land managers with restoration. Live tree and seedling infection by white pine blister rust increased over the last decade and cascading effects of the disease are intensifying, including canopy kill and mortality. We show that large diameter trees are more likely to be infected, and the highest infection rates are in southern and western areas. The conditions for seedling infection are more strongly influenced by fine-scale climatic conditions than for trees. Areas with low regeneration are: (1) the dry east slopes where live tree infection is low; and (2) where live tree infection rates are high, suggesting that canopy kill and mortality are influencing regeneration. Results highlight where to target restoration and coordinate across boundaries.

The Alpine Club of Canada’s ‘Mountain Heritage’: Adventure and Advocacy in the Twentieth Century and Beyond

Founded in 1906, the Alpine Club of Canada (ACC) was a key proponent of mountain adventure and advocacy. This paper examines the club’s annual camps, physical culture, and conservation involvement as indicators to understand the integration of mountaineering and parks in Canada in the twentieth century. It surveys the club’s origins and highlights its shifting agendas. The ACC mountaineering camps and classic alpine ascents invented a tradition for middle-class sport and tourism in mountain parks, particularly in the Rockies and Columbia Mountains. The club advocated for climbers but also for conservation in wild places. It participated in contested debates on parks and resource use as a stakeholder on public lands. The paper argues the ACC was a leading proponent of mountain pursuits, conservation, and tourism in a complex political ecology of engaged land use for sport and recreation intertwined with physical spaces and the social production of mountain parks in Canada. Adventure and advocacy were its legacy as well as education on the land. Based on archives, alpine journals, and other published sources, the paper illustrates an integration of people and places in landscapes of sport as well as contemporary mountain adventure, tourism, and conservation issues in Canada and internationally.

Forest vegetation change and disturbance interactions over the past 7500 years at Sasquatch Lake, Columbia Mountains, western Canada

Fire is the most important abiotic disturbance in the interior cedar-hemlock (ICH) and Engelmann spruce–subalpine fir (ESSF) forest zone of southeastern British Columbia, Canada. Other disturbances are also important, such as defoliator and boring insect outbreaks, windthrow, diseases, and rapid mass movements. Few studies have examined the interaction between multiple types of disturbances in these forests over long timescales. Here we present high-resolution analyses of biomass burning, erosion, and vegetation assemblage changes at Sasquatch Lake (NEL02), a valley lake in the Columbia Mountains. The 531.5 cm sediment core was radiocarbon dated and provided a 7500-year stratigraphy that was used for pollen, macroscopic charcoal (>150 μm), and sedimentologic analyses. Pollen and charcoal data provided evidence of forest composition changes and fire activity. Magnetic susceptibility, loss-on-ignition, and particle size distribution analyses characterised changes in erosion into the basin. The results show that coniferous forests, with a high abundance of Pinus pollen, had established in the catchment by the beginning of the record and were subject to intermittent burning and high-energy erosive events. Tsuga heterophylla expanded by 4400 cal BP and the modern interior cedar-hemlock forests expanded throughout the lower elevations due to increased regional continentality since 4500 cal BP. High-energy erosional inputs to the lake were less frequent from 3500 to 750 cal BP and rapid mass movements may have increased in frequency during the Little Ice Age. Dendrochronological evidence in these stands suggests a mixed-severity fire regime during past ∼300 years, which has not been fully examined for charcoal-based fire event reconstruction. Here we use identified peaks as an indicator of increased biomass burning and charcoal movement in the catchment in relation to peaks in allochthonous clastic material to understand the potential relationships between biomass burning and erosion events at multiple temporal scales in the catchment. This suggests that post-fire conditions, up to several decades, were subject to increased erosion to the lake and erosion events were more common during the early Holocene. Establishment of dense ESSF and ICH forests decreased siliciclastic input to the lake throughout the mid Holocene until a recent rockslide. The high-resolution sampling of this lake sediment record provides long-term evidence of variability in the relationships between vegetation cover, fire and erosion at a catchment scale.

Validating the Space-Time Model for Infrequent Snow Avalanche Events Using Field Observations from the Columbia and Rocky Mountains, Canada

ABSTRACTAvalanche runout distance and return period estimates are essential to snow avalanche risk assessment for hazard mapping and mitigation design. We present a validation of the Space-Time (ST) model, a statistical model that expresses runout distance as a function of return period. The validation is based on field observations of tree damage and tree ring data of infrequent (1:5 to 1:100 year return period) avalanches from 34 paths in the Canadian Rocky and Columbia Mountains. While the ST model has been applied successfully for a longer return period (>100 year) runouts in one path, our validation showed that it does not independently estimate infrequent runout distances with sufficient accuracy for hazard mapping and mitigation design. As with estimating extreme runouts, it should be used in combination with other methods. The model was found to perform differently across mountain ranges, and tended to estimate runout distance downslope of those observed in the field.

Meteorological, elevation, and slope effects on surface hoar formation

Abstract. Failure in layers of buried surface hoar crystals (frost) can cause hazardous snow slab avalanches. Surface hoar crystals form on the snow surface and are sensitive to micro-meteorological conditions. In this study, the role of meteorological and terrain factors was investigated for three layers of surface hoar in the Columbia Mountains of Canada. The distribution of crystals over different elevations and aspects was observed on 20 days of field observations during a period of high pressure. The same layers were modelled over simplified terrain on a 2.5 km horizontal grid by forcing the snow cover model SNOWPACK with forecast weather data from a numerical weather prediction model. Modelled surface hoar growth was associated with warm air temperatures, high humidity, cold surface temperatures, and low wind speeds. Surface hoar was most developed in regions and elevation bands where these conditions existed, although strong winds at high elevations caused some model discrepancies. SNOWPACK simulations on virtual slopes systematically predicted smaller surface hoar on south-facing slopes. In the field, a complex combination of surface hoar and sun crusts were observed, suggesting the simplified model did not adequately resolve the surface energy balance on slopes. Overall, a coupled weather–snow cover model could benefit avalanche forecasters by predicting surface hoar layers on a regional scale over different elevation bands.

Patterns of bedload entrainment and transport in forested headwater streams of the Columbia Mountains, Canada

AbstractWe monitor bedload transport and water discharge at six stations in two forested headwater streams of the Columbia Mountains, Canada. The nested monitoring network is designed to examine the effects of channel bed texture, and the influence of alluvial (i.e. step pools and riffle pools) and semialluvial morphologies (i.e. boulder cascades and forced step pools) on bedload entrainment and transport. Results indicate that dynamics of bedload entrainment are influenced by differences in flow resistance attributable to morphology. Scaled fractional analysis shows that in reaches with high form resistance most bedload transport occurs in partial mobility fashion relative to the available bed material, while calibers finer than 16 mm attain full mobility during bankfull flows. Equal mobility transport for a wider range of grain sizes is achieved in reaches exhibiting reduced form resistance. Our findings confirm that the Shields value for mobilization of the median surface grain size depends on channel gradient and relative submergence; however, we also find that these relations vary considerably for cobble and gravel bed channels due to proportionality between dimensionless shear stress and grain size. Exponents of bedload rating curves across sites correlate most with the D90s of the mobile bed, however, where grain effects are controlled (i.e. along individual streams), differences in form resistance across morphologies exert a primary control on bedload transport dynamics. Application of empirical formulae developed for use in steep alpine channels present variable success in predicting transport rates in forested snowmelt streams. Formulae that explicitly account for reductions in mobile bed area and high morphological resistance associated with woody debris provide the best approximation to observed empirical data. Copyright © 2014 John Wiley & Sons, Ltd.

Modelling the formation of surface hoar layers and tracking post-burial changes for avalanche forecasting

Predicting the spatial distribution and persistence of buried surface hoar layers is important when evaluating avalanche hazard. This study used weather-based models to predict the formation of surface hoar and investigated how buried layers change over time. Seven years of study plot observations from the Columbia Mountains of British Columbia were used to calibrate models for surface hoar formation. The latent heat flux was modelled with weather station data and forecasted data from the Canadian numerical weather prediction model (GEM15). A linear relationship was found between vapour mass flux and observed surface hoar crystal size (r2 of 0.84 with weather station data and 0.70 with GEM15 data), and was used to predict crystal size over seven winters. Crystal size predictions had root mean square errors of 2.4 and 4.1mm with weather station and GEM15 data, respectively. The model was compared with other empirical weather-based models. Layers of buried surface hoar were tracked with shear frame tests, compression tests (CT) and propagation saw tests (PST). PSTs and fracture character in CTs indicated that the propensity for propagation in layers of surface hoar remained high for up to six weeks. Layers with large crystals were found to weakly indicate low stability. Results from this study could be used to improve the representation of surface hoar layers in snow cover models and make spatial predictions with NWP data.