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1
Bobrowsky, Peter, and Nathaniel W. Rutter. "The Quaternary Geologic History of the Canadian Rocky Mountains." Géographie physique et Quaternaire 46, no. 1 (November 23, 2007): 5–50. http://dx.doi.org/10.7202/032887ar.
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ABSTRACT The Canadian Rocky Mountains figured prominently during the glacial history of western Canada. First as a western limit or boundary to the Laurentide Ice Sheet, second as an eastern margin of the Cordilleran Ice Sheet, and finally as a centre of local Montane ice. Throughout the Quaternary, complex interactions of glacier ice from these three ice sources markedly changed the physical form of the Rocky Mountains, Trench and Foothills areas. Investigations into the Quaternary history of this region have been ongoing since the beginning of the last century. Since about 1950, the number of studies performed in this area have increased significantly. This paper briefly reviews the historical accomplishments of Quaternary work in the region up to the period of about 1950. From this time to the present, individual study efforts are examined in detail according to the three geographic regions: 1) the northern Rocky Mountains (from the Liard Plateau south to the McGregor Plateau), 2) the central Rocky Mountains (from the McGregor Plateau south to the Porcupine Hills) and 3) the southern Rocky Mountains (from the Porcupine Hills south to the international border). In the northern region, geologic data suggest a maximum of two Rocky Mountain glaciations and only one Laurentide glaciation and no ice coalescence. In the central region, three of four Rocky Mountain events, and at least two Laurentide events are known. Only in the central region is there good evidence for ice coalescence, but the timing of this event is not clearly established. In the south, at least three Rocky Mountain episodes and a variable number of Laurentide episodes are recognized. There is no evidence for ice coalescence. A number of facts support the proposal that Cordilleran ice crossed the Continental Divide and joined with local Montane ice at several locations. However, this expansion of western ice occurred before the Late Wisconsinan in all areas but Jasper. In general, the chronological data presented suggest that the Late Wisconsinan glaciation in the Rocky Mountains was a short-lived event which started around or after 20 ka years ago and ended before 12 ka ago.
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Sjostrom, Derek J., Michael T. Hren, and C. Page Chamberlain. "Oxygen isotope records of goethite from ferricrete deposits indicate regionally varying holocene climate change in the Rocky Mountain region, U.S.A." Quaternary Research 61, no. 1 (January 2004): 64–71. http://dx.doi.org/10.1016/j.yqres.2003.08.008.
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Oxygen isotopes of goethite from ferricrete deposits were measured from both northern and southern Rocky Mountain localities to assess geographic variability in regional Holocene paleoclimate change. A ∼3.7‰ increase in oxygen isotope values of 14C-dated goethites in the northern Rocky Mountains suggests a regional-scale relative increase in amounts of isotopically heavy summer precipitation since the early Holocene. In contrast, oxygen isotope values from the southern Rocky Mountains increase abruptly ∼2.1‰ at ∼6200 14C yr B.P. then decrease ∼2.4‰ between ∼2000 14C yr B.P. and the present. We interpret this period of relatively high δ18O values as evidence for a middle Holocene warm period combined with a relatively strong summer monsoon. These variable climate records suggest that the Rocky Mountains of the western United States have had a spatially heterogeneous Holocene climate history.
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Gray, Philip Howard. "‘A Turrible Looking and Furious Anamal’: Comparative Psychology in the Rocky Mountains from Lewis and Clark to Washoe." Psychological Reports 60, no. 1 (February 1987): 59–62. http://dx.doi.org/10.2466/pr0.1987.60.1.59.
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A preliminary attempt is made to identify the progress of the study of animal behavior, from native bears to imported apes, in the Rocky Mountain region. The survey includes naturalistic encounters, ethological observations, and laboratory studies, but is not a complete enumeration of animal research in the Rocky Mountains.
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Rovnak, Joel, Laura A. St. Clair, Elena Lian, Carley McAlister, Rushika Perera, and Randall J. Cohrs. "The 19th Rocky Mountain Virology Association Meeting." Viruses 12, no. 1 (January 11, 2020): 85. http://dx.doi.org/10.3390/v12010085.
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This autumn, 95 scientists and students from the Rocky Mountain area, along with invited speakers from Colorado, California, Montana, Florida, Louisiana, New York, Maryland, and India, attended the 19th annual meeting of the Rocky Mountain Virology Association that was held at the Colorado State University Mountain Campus located in the Rocky Mountains. The two-day gathering featured 30 talks and 13 posters—all of which focused on specific areas of current virology and prion protein research. The keynote presentation reviewed new tools for microbial discovery and diagnostics. This timely discussion described the opportunities new investigators have to expand the field of microbiology into chronic and acute diseases, the pitfalls of sensitive molecular methods for pathogen discovery, and ways in which microbiology help us understand disruptions in the social fabric that pose pandemic threats at least as real as Ebola or influenza. Other areas of interest included host factors that influence virus replication, in-depth analysis of virus transcription and its effect on host gene expression, and multiple discussions of virus pathology, epidemiology as well as new avenues of diagnosis and treatment. The meeting was held at the peak of fall Aspen colors, surrounded by five mountains >11,000 ft (3.3 km), where the secluded campus provided the ideal setting for extended discussions, outdoor exercise and stargazing. On behalf of the Rocky Mountain Virology Association, this report summarizes 43 selected presentations.
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Polziehn, R. O., J. Hamr, F. F. Mallory, and C. Strobeck. "Phylogenetic status of North American wapiti( Cervus elaphus) subspecies." Canadian Journal of Zoology 76, no. 6 (June 1, 1998): 998–1010. http://dx.doi.org/10.1139/z98-026.
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By the turn of the century, North American elk, or wapiti (Cervus elaphus), had been extirpated from all regions ofthe continent and two subspecies were extinct. The recovery of wapiti is largely a response to the large number of relocatedRocky Mountain (C. e. nelsoni) and Manitoban wapiti (C. e. manitobensis). A phylogenetic study was performed to determinethe present genetic relationships among tule (C. e. nannodes), Roosevelt (C. e. roosevelti), Rocky Mountain, and Manitobansubspecies, using sequences from the D-loop region of the mitochondrial DNA of 28 individuals. All Roosevelt wapiti weregrouped together, as were tule wapiti, which supports the classification of tule and Roosevelt subspecies. Yellowstone, ElkIsland, and Riding Mountain National Parks have not introduced wapiti into their indigenous populations. When thesepopulations were used, Manitoban wapiti were found to be monophyletic and Rocky Mountain wapiti to be paraphyletic.However, including animals from the Canadian Rocky Mountains places Rocky Mountain wapiti in clades by themselves orgrouped with Manitoban wapiti. The clade containing a mixture of Manitoban and Rocky Mountain wapiti suggests that bothtypes recently descended from a common ancestor. Hybridization or insufficient time for separation may explain the presenceof the two types in the same clade.
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Lehmann-Horn, J. A., J. O. Walbrecker, M. Hertrich, G. Langston, A. F. McClymont, and A. G. Green. "Imaging groundwater beneath a rugged proglacial moraine." GEOPHYSICS 76, no. 5 (September 2011): B165—B172. http://dx.doi.org/10.1190/geo2011-0095.1.
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With the changing precipitation patterns and melting of mountain glaciers and permafrost that result from global warming, information on the distribution of groundwater in mountainous terrains is becoming increasingly important for developing prudent resource and hazard management strategies. Obtaining this information across topographically craggy and variably frozen ground in a cost-effective and nonintrusive manner is challenging. We introduce a modified 2D surface nuclear magnetic resonance (NMR) tomographic technique that allows us to account for substantial variations in surface topography in locating and quantifying groundwater occurrences in rugged mountains. Because contact with the ground is not necessary, it is a rare geophysical technique not affected by sensor-to-ground coupling problems common in high mountain environments. To demonstrate the efficacy of the tomographic imaging scheme, we invert a large multioffset surface NMR data set collected across a partially ice-cored proglacial terminal moraine in the Canadian Rocky Mountains. Our preferred model contains a 2- to 5-m-thick water layer, the top of which has practically the same elevation as the surface of a nearby lake and the bottom of which coincides with bedrock resolved in companion seismic and ground-penetrating radar studies.
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Margold, Martin, John C. Gosse, Alan J. Hidy, Robin J. Woywitka, Joseph M. Young, and Duane Froese. "Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka." Quaternary Research 92, no. 2 (April 17, 2019): 469–82. http://dx.doi.org/10.1017/qua.2019.10.
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AbstractThe Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. We use 10Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 ± 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. A later separation of the western LIS margin from the mountain front implies higher ice margin–retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later.
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Jabbarov, MT, AS Ibragimov, FH Nabieva, VV Atamov, and S. Karaman Erkul. "Phytosociological features of frigana vegetation of Nakhchivan, Azerbaijan." Bangladesh Journal of Botany 49, no. 2 (September 19, 2020): 273–86. http://dx.doi.org/10.3329/bjb.v49i2.49300.
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The phytosociological and floristic properties of mountain xerophyte plant associations (Frigana) spread on the territory of Nakhchivan Autonomous Republic of Azerbaijan were investigated. These unions are dominated by barbed and grassy plants. On the other hand Acantholimon spp., Astragalus spp. and Onobrychis cornuta are common in the area and dominant in the mountainous regions of Nakhchivan. The major parts of Shahbuz, Julfa and Ordubad are dominanted by vegetation. In the floristic composition of the frigana units the shrubs are dominant and the characteristic species are: Pyrus oxyprion, Astragalus microcephalus, Astragalus aureus, Juniperus polycarpos, Rhamnus pallasii, Atraphaxis spinosa, Acantholimon bracteatum, Rhus coriaria, Acer ibericum, Lonicera iberica, Prangos ferulacea, Thymus kotschyanus etc. The frigana units dominate the region's vegetation. The mountainous xerophyte vegetation encompasses strongly torn by relief, rocky slopes, and talus of the territory of the mountains. The continentalization of the climate after the glacial era, as well as the advent of anthropogenic activity, appears to be effective in expanding the range of vegetation. Although skeleton is the only plant bitumen in the rocky slopes, it is important to protect the dive lining of the slopes along the slopes and to prevent the wash away and spoilage residues.
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Leary, Ryan J., Paul Umhoefer, M. Elliot Smith, Tyson M. Smith, Joel E. Saylor, Nancy Riggs, Greg Burr, et al. "Provenance of Pennsylvanian–Permian sedimentary rocks associated with the Ancestral Rocky Mountains orogeny in southwestern Laurentia: Implications for continental-scale Laurentian sediment transport systems." Lithosphere 12, no. 1 (January 30, 2020): 88–121. http://dx.doi.org/10.1130/l1115.1.
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Abstract The Ancestral Rocky Mountains system consists of a series of basement-cored uplifts and associated sedimentary basins that formed in southwestern Laurentia during Early Pennsylvanian–middle Permian time. This system was originally recognized by aprons of coarse, arkosic sandstone and conglomerate within the Paradox, Eagle, and Denver Basins, which surround the Front Range and Uncompahgre basement uplifts. However, substantial portions of Ancestral Rocky Mountain–adjacent basins are filled with carbonate or fine-grained quartzose material that is distinct from proximal arkosic rocks, and detrital zircon data from basins adjacent to the Ancestral Rocky Mountains have been interpreted to indicate that a substantial proportion of their clastic sediment was sourced from the Appalachian and/or Arctic orogenic belts and transported over long distances across Laurentia into Ancestral Rocky Mountain basins. In this study, we present new U-Pb detrital zircon data from 72 samples from strata within the Denver Basin, Eagle Basin, Paradox Basin, northern Arizona shelf, Pedregosa Basin, and Keeler–Lone Pine Basin spanning ∼50 m.y. and compare these to published data from 241 samples from across Laurentia. Traditional visual comparison and inverse modeling methods map sediment transport pathways within the Ancestral Rocky Mountains system and indicate that proximal basins were filled with detritus eroded from nearby basement uplifts, whereas distal portions of these basins were filled with a mix of local sediment and sediment derived from marginal Laurentian sources including the Arctic Ellesmerian orogen and possibly the northern Appalachian orogen. This sediment was transported to southwestern Laurentia via a ca. 2,000-km-long longshore and aeolian system analogous to the modern Namibian coast. Deformation of the Ancestral Rocky Mountains slowed in Permian time, reducing basinal accommodation and allowing marginal clastic sources to overwhelm the system.
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Argus, George W. "Studies of the Salix lucida and Salix reticulata complexes in North America." Canadian Journal of Botany 64, no. 3 (March 1, 1986): 541–51. http://dx.doi.org/10.1139/b86-069.
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A study of morphological variation in the Salix lucida complex revealed three geographical races: one in northeastern North America, a second in western North America extending from Alaska to California, and a third in the southern Rocky Mountains, S. lucida ssp. lucida, Salix lucida ssp. lasiandra comb, nov., and Salix lucida ssp. caudata comb, nov., respectively. The Salix reticulata complex in the Rocky Mountain region is represented by two geographical races, ssp. reticulata in the north and ssp. nivalis in the south. Variation in ssp. nivalis suggests that hybridization and introgression occur where the two races overlap, and that the results of past hybridization are still evident in the southern Rocky Mountains.
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Gruber, Urs, Pascal Hägeli, David M. McClung, and Evan Manners. "Large-scale snow instability patterns in western Canada: first analysis of the CAA–InfoEx database 1991–2002." Annals of Glaciology 38 (2004): 15–20. http://dx.doi.org/10.3189/172756404781814979.
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AbstractDaily weather measurements, snow stability assessments and recorded weak layers of 23 stations covering an observation area of approximately 40 000 km2 in western Canada were analyzed. The study area includes three major mountain ranges with different snow climates. All stations included assess the stability of the snow cover. However, the focus of the avalanche safety program of the different types of operation (heli-ski operation, ski resorts and parks) varies significantly. The three stations in the Coast Mountains show the highest snow stability, followed by the South Columbia Mountains and then the North Columbia and Rocky Mountains. The weather data were analyzed to try to explain some of these differences. Intensive snowfall at relatively high temperatures proved to be important for the higher snow stability over the season in the Coast Mountains. Theweak-layer data were used to complement the snow stability assessments. Most persistent weak layers were reported in the Columbia Mountains, followed by the three stations in the Coast Mountains and trailed by the Rocky Mountains. Although some weather observations indicate climatic reasons for the smaller number of weak layers in the Rocky Mountains, it cannot be excluded that these differences are also related to the different type of operations.
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Aguirre, Tomás Martínez, Judit E. Dopazo, Agustina Cortelezzi, María Luz Arellano, Clara Trofino Falasco, María Verónica Simoy, and Igor Berkunsky. "Two New Species of the Genus Melanophryniscus (Amphibia: Anura: Bufonidae) from Pampa Grasslands of Argentina." Russian Journal of Herpetology 28, no. 2 (May 3, 2021): 108–16. http://dx.doi.org/10.30906/1026-2296-2021-28-2-108-116.
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Two new species of small-sized terrestrial toad of the genus Melanophryniscus from the highland grasslands of the Ventania and Tandilia Mountain Systems in Buenos Aires province, Argentina, are described. We assign provisionally Melanophryniscus diabolicus sp. nov. (Ventania mountains) and Melanophryniscus nigricans sp. nov. (Tandilia mountains) as both belonging to the Melanophryniscus stelzneri group. The new species differs from other congeners by a distinctive combination of characters: dorsum dark black, tympanum concealed, venter blackish, and distribution on highland rocky grasslands in the mountains of Tandilia (M. nigricans sp. nov.), and on highland rocky grasslands in the mountains of Ventania and coastal dune grassland (M. diabolicus sp. nov.). Moreover, the advertisement call of the new species is noticeable different between species and close related species M. atroluteus and M. montevidensis. Both species have experienced local extinctions and should be categorized as threatened species.
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Rovnak, Joel, Laura Clair, Kirsten Krieger, Elena Lian, Rushika Perera, and Randall Cohrs. "The 18th Rocky Mountain Virology Association Meeting." Viruses 11, no. 1 (December 21, 2018): 4. http://dx.doi.org/10.3390/v11010004.
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This autumn, approximately 100 scientists and students from the Rocky Mountain area along with invited speakers attended the 18th annual meeting of the Rocky Mountain Virology Association that was held at the Colorado State University Mountain Campus. The two-day gathering featured 31 talks and 33 posters all of which focused on specific areas of current virology and prion protein research. Since the keynote presentation focused on the oligoadenylate synthetase-ribonuclease L pathway the main area of focus was on host–virus interactions, however other areas of interest included virus vectors, current models of virus infections, prevention and treatment of virus infections, separate sessions on RNA viruses and prion proteins, and a special talk highlighting various attributes of targeted next-generation sequencing. The meeting was held at the peak of the fall Aspen colors surrounded by five mountains >11000 ft (3.3 km) where the secluded campus provided the ideal setting for extended discussions and outdoor exercise. On behalf of the Rocky Mountain Virology Association, this report summarizes 42 selected presentations.
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Nykanen, Deborah K. "Linkages between Orographic Forcing and the Scaling Properties of Convective Rainfall in Mountainous Regions." Journal of Hydrometeorology 9, no. 3 (June 1, 2008): 327–47. http://dx.doi.org/10.1175/2007jhm839.1.
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Abstract Heavy rainfall over mountainous terrain often results in catastrophic flooding and presents a great challenge for forecasters. Statistical downscaling methods provide a way to bridge across the scale gap between rainfall forecasts from numerical weather prediction models and the high-resolution needs of hydrologic models for flash flood prediction. In this study, multiscale statistical analysis was used to analyze several heavy convective rainfall events that produced catastrophic flooding in the Appalachian Mountains and Front Range of the Rocky Mountains with the motivation of developing predictive relationships for a priori parameter estimation needed in downscaling applications. The multiscale behavior of the rainfall was analyzed over time and linked to underlying topographic elevation and predominate orographic forcing. It was found that in storms located on the leeward side (i.e., the side of the mountain facing away from the upper-level winds), one of the parameters increased with increasing topographic elevation. An opposite trend was found for this parameter in storms located on the windward side (i.e., the side of the mountain facing toward the direction of the upper-level winds). These trends held across different geographical regions and both upslope and downslope directions of storm motion. The interaction between orographic and meteorological forcings was found to be important in developing predictive relationships for the multiscale statistical parameters.
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Wu, Chenglai, Xiaohong Liu, Zhaohui Lin, Stefan R. Rahimi-Esfarjani, and Zheng Lu. "Impacts of absorbing aerosol deposition on snowpack and hydrologic cycle in the Rocky Mountain region based on variable-resolution CESM (VR-CESM) simulations." Atmospheric Chemistry and Physics 18, no. 2 (January 18, 2018): 511–33. http://dx.doi.org/10.5194/acp-18-511-2018.
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Abstract. The deposition of light-absorbing aerosols (LAAs), such as black carbon (BC) and dust, onto snow cover has been suggested to reduce the snow albedo and modulate the snowpack and consequent hydrologic cycle. In this study we use the variable-resolution Community Earth System Model (VR-CESM) with a regionally refined high-resolution (0.125°) grid to quantify the impacts of LAAs in snow in the Rocky Mountain region during the period 1981–2005. We first evaluate the model simulation of LAA concentrations both near the surface and in snow and then investigate the snowpack and runoff changes induced by LAAs in snow. The model simulates similar magnitudes of near-surface atmospheric dust concentrations as observations in the Rocky Mountain region. Although the model underestimates near-surface atmospheric BC concentrations, the model overestimates BC-in-snow concentrations by 35 % on average. The regional mean surface radiative effect (SRE) due to LAAs in snow reaches up to 0.6–1.7 W m−2 in spring, and dust contributes to about 21–42 % of total SRE. Due to positive snow albedo feedbacks induced by the LAA SRE, snow water equivalent is reduced by 2–50 mm and snow cover fraction by 5–20 % in the two regions around the mountains (eastern Snake River Plain and southwestern Wyoming), corresponding to an increase in surface air temperature by 0.9–1.1 °C. During the snow melting period, LAAs accelerate the hydrologic cycle with monthly runoff increases of 0.15–1.00 mm day−1 in April–May and reductions of 0.04–0.18 mm day−1 in June–July in the mountainous regions. Of all the mountainous regions, the Southern Rockies experience the largest reduction of total runoff by 15 % during the later stage of snowmelt (i.e., June and July). Compared to previous studies based on field observations, our estimation of dust-induced SRE is generally 1 order of magnitude smaller in the Southern Rockies, which is ascribed to the omission of larger dust particles (with the diameter > 10 µm) in the model. This calls for the inclusion of larger dust particles in the model to reduce the discrepancies. Overall these results highlight the potentially important role of LAA interactions with snowpack and the subsequent impacts on the hydrologic cycles across the Rocky Mountains.
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Johnston, Katherine S., Bruce Jamieson, and Alan Jones. "Estimating extreme avalanche runout for the Columbia Mountains and Fernie area Rocky Mountains of British Columbia, Canada." Canadian Geotechnical Journal 49, no. 11 (November 2012): 1309–18. http://dx.doi.org/10.1139/t2012-079.
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Extreme snow avalanche runout is typically estimated using a combination of historical and vegetation records as well as statistical and dynamic models. The two classes of statistical models (α–β and runout ratio) are based on estimating runout distance past the β-point, which is typically defined as the point where the avalanche slope incline first decreases to 10°. The parameters for these models vary from mountain range to mountain range. In Canada, α–β and runout ratio parameters have been published for the combined Rocky and Purcell Mountains and for the British Columbia Coast Mountains. Despite active development, no suitable tall avalanche path model parameters have been published for the Columbia Mountains or for the Lizard Range area around Fernie, B.C. Using a dataset of 65 avalanche paths, statistical model parameters have been derived for these regions.
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Hein, Peter, Harald Kürschner, and Gerald Parolly. "Phytosociological studies on high mountain plant communities of the Taurus mountains (Turkey) 2. Rock communities." Phytocoenologia 28, no. 4 (November 30, 1998): 465–563. http://dx.doi.org/10.1127/phyto/28/1998/465.
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Westbrook, Cherie J., and Angela Bedard-Haughn. "Sibbald Research Wetland: Mountain peatland form and ecohydrologic function as influenced by beaver." Forestry Chronicle 92, no. 01 (January 2016): 37–38. http://dx.doi.org/10.5558/tfc2016-011.
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Sibbald Research Wetland is a 1.3 km2 peatland in the foothills of the Rocky Mountains. The primary research foci are 1) the influence of beaver ponds on mountain peatland hydrology and 2) the potential influence of climate change on these beaver-impacted peatlands. This paper summarizes initial results and implications of the research.
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Bingham, D. K., D. I. Gough, and M. R. Ingham. "Conductive structures under the Canadian Rocky Mountains." Canadian Journal of Earth Sciences 22, no. 3 (March 1, 1985): 384–98. http://dx.doi.org/10.1139/e85-037.
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The paper reports results from an array of 33 three-component magnetometers that recorded time-varying fields in 1981 over an area of some 56 000 km2 in the Canadian Cordillera. The array was centred at Tête Jaune Cache in the Rocky Mountain Trench, where a large magnetovariation anomaly had been located in an earlier array study. It was bisected by the trench and extended to the northeast across the Rocky Mountains to the Alberta Foothills and to the southwest across the Cariboo and Monashee mountains. Magnetograms and Fourier transform maps covering the period range 10–91 min show strong attenuation of the vertical component, Z, southwest of the Rocky Mountain Trench, with very large Z amplitudes in the Main Ranges of the Rockies. The horizontal components show an elongated anomaly along the Rocky Mountains Main Ranges and Trench, with three-dimensional features superimposed. The conductive structures include a highly conductive layer, probably in the lower crust, southwest of the trench and a conductive ridge rising into the upper crust near the edge of that layer. Current models have been fitted to observed vertical -and horizontal-component anomalies and show that both layer and ridge are necessary for a fit and that the ridge is 50–80 km wide. Single-station transfer functions at periods of 10 and 22 min have been calculated from a number of variation events of various polarizations, to reduce any displacement of the anomalies by auroral-zone source currents. Artificial-event analysis, with these transfer functions, shows that the conductive ridge lies under the Main Ranges of the Rockies and not under the trench. Its great width indicates a structure of major tectonic significance, which will be considered in another paper.
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Flesch, Thomas K., and Gerhard W. Reuter. "WRF Model Simulation of Two Alberta Flooding Events and the Impact of Topography." Journal of Hydrometeorology 13, no. 2 (April 1, 2012): 695–708. http://dx.doi.org/10.1175/jhm-d-11-035.1.
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Abstract This study examines simulations of two flooding events in Alberta, Canada, during June 2005, made using the Weather Research and Forecasting Model (WRF). The model was used in a manner readily accessible to nonmeteorologists (e.g., accepting default choices and parameters) and with a relatively large spatial resolution for rapid model runs. The simulations were skillful: strong storms were developed having the correct timing and location, generating precipitation rates close to observations, and with precipitation amounts near that observed. The model was then used to examine the sensitivity of the two storms to the topography of the Rocky Mountains. Comparing model results using the actual topographic grid with those of a reduced-mountain grid, it is concluded that a reduction in mountain elevation decreases maximum precipitation by roughly 50% over the mountains and foothills. There was little sensitivity to topography in the precipitation outside the mountains.
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Czarnetzki, Alan C. "Regional Mountain Torque Estimates over the Rocky Mountains in Lee Cyclones." Journal of the Atmospheric Sciences 54, no. 15 (August 1997): 1986–97. http://dx.doi.org/10.1175/1520-0469(1997)054<1986:rmteot>2.0.co;2.
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Strong, W. L. "Mountain Park area: a plant refugium in the Canadian Rocky Mountains?" Journal of Biogeography 26, no. 2 (March 1999): 413–23. http://dx.doi.org/10.1046/j.1365-2699.1999.00289.x.
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Höy, Trygve, and P. van der Heyden. "Geochemistry, geochronology, and tectonic implications of two quartz monzonite intrusions, Purcell Mountains, southeastern British Columbia." Canadian Journal of Earth Sciences 25, no. 1 (January 1, 1988): 106–15. http://dx.doi.org/10.1139/e88-011.
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The Reade Lake and Kiakho stocks are posttectonic mesozonal quartz monzonite porphyries that intrude dominantly Middle Proterozoic Purcell Supergroup rocks in southeastern British Columbia. K–Ar dates of hornblende from the Reade Lake stock range from 103 to 143 Ma. However, a U–Pb date of 94 Ma from zircon concentrates is interpreted to be the age of emplacement of the stock, suggesting the range and older K–Ar dates are due to excess 40Ar. A K–Ar date of 122 Ma for the hornblende from the Kiakho stock is believed to be a more reliable intrusive age.Both stocks cut across and apparently seal two faults that have played roles in the tectonic evolution of the Purcell anticlinorium and Rocky Mountain thrust belt. The Reade Lake stock cuts the St. Mary fault, an east-trending reverse thrust that crosses the Rocky Mountain trench and links with thrusts in the Rocky Mountains; the Kiakho stock cuts the Cranbrook fault, an older east-trending normal fault. Hence, the 94 Ma date on the Reade Lake stock constrains the latest movement on the St. Mary fault to early Late Cretaceous; and the 122 Ma date on the Kiakho stock appears to limit latest movement on the Cranbrook fault to Early Cretaceous. These faults and the intrusions are part of an allochthonous package, displaced eastward by underlying thrust faults during formation of the Purcell anticlinorium and more eastern thrusts in the Rocky Mountains.
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Schnabel, Andrew, J. L. Hamrick, and P. V. Wells. "Influence of Quaternary history on the population genetic structure of Douglas-fir (Pseudotsugamenziesii) in the Great Basin." Canadian Journal of Forest Research 23, no. 9 (September 1, 1993): 1900–1906. http://dx.doi.org/10.1139/x93-240.
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We used data from 20 enzyme loci to test hypotheses concerning the population genetic structure of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) in the Great Basin relative to the southern Rocky Mountains of Utah. Detailed macrofossil data from wood rat (Neotoma) middens indicate that P. menziesii was absent from the central and northern Great Basin during the last glacial (20 000–12 000 years before present), but has recolonized several of the "island" mountain ranges of that region during the past 10 000 years by long-distance dispersal from populations on the southern Rocky Mountain "mainland". The genetic consequences of rare, chance dispersal events should be a reduction in levels of genetic diversity on Great Basin montane islands and more diversity among island populations relative to the Rocky Mountain mainland. We found moderate overall reductions in the level of polymorphism (65 vs. 85%), numbers of alleles per polymorphic locus (2.69 vs. 2.82), and gene diversity (0.113 vs. 0.141) in Great Basin P. menziesii relative to P. menziesii from the Rocky Mountain mainland. Within-population estimates of allozyme diversity, as well as relative partitioning of that diversity among populations of each region, differed to a lesser extent between island and mainland regions. Founder effects and genetic drift thus appear to have had a minor role in shaping the present-day genetic structure of Great Basin P. menziesii populations.
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Lerner-Lam, A. L., A. Sheehan, S. Grand, E. Humphreys, K. Dueker, E. Hessler, H. Guo, D. K. Lee, and M. Savage. "Deep structure beneath the Southern Rocky Mountains from the Rocky Mountain Front Broadband Seismic Experiment." Rocky Mountain Geology 33, no. 2 (October 1, 1998): 199–216. http://dx.doi.org/10.2113/33.2.199.
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Balestra and Nüesch. "Mitbringsel aus den Ferien." Praxis 94, no. 47 (November 1, 2005): 1869–70. http://dx.doi.org/10.1024/0369-8394.94.47.1869.
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Eine 37-jährige Patientin stellt sich nach der Rückkehr von einer Rundreise durch Nordamerika mit einem Status febrilis seit zehn Tagen und einem makulösem extremitätenbetontem Exanthem seit einem Tag vor. Bei suggestiver Klinik und Besuch der Rocky Mountains wird ein Rocky Mountain spotted fever diagnostiziert. Die Serologie für Rickettsia conorii, die mit Rickettsia rickettsii kreuzreagiert, war positiv und bestätigte die klinische Diagnose. Allerdings konnte der beweisende vierfache Titeranstieg, möglicherweise wegen spät abgenommener ersten Serologie, nicht nachgewiesen werden. Nach zweiwöchiger antibiotischer Therapie mit Doxycycline waren Status febrilis und Exanthem regredient.
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Letcher, Theodore W., and Justin R. Minder. "The Simulated Impact of the Snow Albedo Feedback on the Large-Scale Mountain–Plain Circulation East of the Colorado Rocky Mountains." Journal of the Atmospheric Sciences 75, no. 3 (February 22, 2018): 755–74. http://dx.doi.org/10.1175/jas-d-17-0166.1.
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Abstract The Front Range mountain–plain circulation (FRMC) is a large-scale diurnally driven wind system that occurs east of the Colorado Rocky Mountains in the United States and affects the weather both in the Rocky Mountains and Great Plains. As the climate warms, the snow albedo feedback will amplify the warming response in the Rocky Mountains during the spring, increasing the thermal contrast that drives the FRMC. In this study, the authors perform a 7-yr pseudo–global warming (PGW) regional climate change experiment along with an idealized PGW “fixed albedo” experiment to test the sensitivity of the FRMC to the snow albedo feedback (SAF). The authors find a mean increase in the springtime FRMC strength in the PGW experiment that is primarily driven by the snow albedo feedback. Furthermore, interannual variability of changes in FRMC strength is strongly influenced by interannual variability in the SAF. An additional case study experiment configured with a much higher resolution is performed to examine the finescale details of how the SAF and the FRMC interact. This experiment includes a passive tracer to investigate subsequent impacts on pollution transport. The case study reveals that loss of snow cover causes an increase in the strength of the FRMC. Advection by the strengthened FRMC increases the concentration of tracers emitted over the Great Plains in the boundary layer over the Front Range mountains.
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Tucker, Donna F., and N. Andrew Crook. "Flow over Heated Terrain. Part II: Generation of Convective Precipitation." Monthly Weather Review 133, no. 9 (September 1, 2005): 2565–82. http://dx.doi.org/10.1175/mwr2965.1.
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Abstract Previous studies have shown that thunderstorms in the Rocky Mountain region have preferred areas in which to form. There has been some indication that these areas depend on the midtropospheric wind direction. A nonhydrostatic model with a terrain-following horizontal grid is employed to investigate the initiation of precipitating convection over heated topography. Horizontally homogeneous meteorological conditions with no directional shear in the vertical wind profile are used. The numerical simulations indicate that precipitating convection was more likely to be generated downwind of ridges than upwind of them. Initiation of these storms was more likely downwind of ridges with their long axis parallel to the wind direction than downwind of ridges with their long axis perpendicular to the wind direction. In Part I of this study it was shown that heating-induced convergence is larger downwind of a ridge with its longer axis parallel to the wind direction. For the orographic configuration of the Rocky Mountains, total precipitation is maximized for southerly and northwesterly winds. Slower wind speeds are more likely and faster wind speeds are less likely to produce convective storms. Soundings with larger instability are more likely to produce convection. The soundings with a greater temperature lapse rate produce more initiation locations, and soundings with greater moisture produce greater amounts of precipitation. Even though a number of assumptions were made for this study, the authors believe the results explain a significant amount of the observed variability in the initiation locations of precipitating convection in the Rocky Mountains during the summer. Because of the theoretical basis for this work, detailed in Part I of this study, the authors believe it should explain convective initiation in other mountainous areas that are subject to strong solar heating.
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Fyfe, John C., and Gregory M. Flato. "Enhanced Climate Change and Its Detection over the Rocky Mountains." Journal of Climate 12, no. 1 (January 1, 1999): 230–43. http://dx.doi.org/10.1175/1520-0442-12.1.230.
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Abstract Results from an ensemble of climate change experiments with increasing greenhouse gas and aerosols using the Canadian Centre for Climate Modelling and Analysis Coupled Climate Model are presented with a focus on surface quantities over the Rocky Mountains. There is a marked elevation dependency of the simulated surface screen temperature increase over the Rocky Mountains in the winter and spring seasons, with more pronounced changes at higher elevations. The elevation signal is linked to a rise in the snow line in the winter and spring seasons, which amplifies the surface warming via the snow-albedo feedback. Analysis of the winter surface energy budget shows that large changes in the solar component of the radiative input are the direct consequence of surface albedo changes caused by decreasing snow cover. Although the warming signal is enhanced at higher elevations, a two-way analysis of variance reveals that the elevation effect has no potential for early climate change detection. In the early stages of surface warming the elevation effect is masked by relatively large noise, so that the signal-to-noise ratio over the Rocky Mountains is no larger than elsewhere. Only after significant continental-scale warming does the local Rocky Mountain signal begin to dominate the pattern of climate change over western North America (and presumably also the surrounding ecosystems and hydrological networks).
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Spensberger, Clemens, Joseph Egger, and Thomas Spengler. "Synoptic Systems Interacting with the Rocky Mountain Barrier: Observations and Theories." Monthly Weather Review 145, no. 3 (March 2017): 783–94. http://dx.doi.org/10.1175/mwr-d-16-0195.1.
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Using a composite analysis for strong sea level pressure perturbations off the west coast of North America, the evolution of large-amplitude synoptic systems upstream of the Rocky Mountains is investigated for the winter season. Corresponding previous analyses are refined by avoiding multiple counting of events and extended by including potential vorticity, vertical motion, and deformation in the analysis. Cyclonic and anticyclonic anomalies behave similarly, with weak local extrema forming in the lee of the mountain range southeast of the parent systems. However, neither the geopotential anomaly nor the associated potential vorticity anomaly cross the mountain range. Nevertheless, these anomalies contribute to the sea level pressure anomaly in the lee. For both positive and negative anomalies, potential vorticity exhibits a bipolar structure with lobes over the reference point and over the Cordillera, respectively. The relevance of several theories describing the interaction between synoptic systems and mountains are discussed in the light of these findings. It is important to note that these findings differ considerably from results reported in an earlier study. Key differences are the previously reported passage of a wave train over the reference point and the movement of the anomalies over the Rocky Mountains. Both features are absent in the current analysis. However, these features can be recovered if a 6-day high-pass filter is applied before the events are selected or if the analysis is applied to predominantly zonal flow situations.
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Malone, David, John Craddock, Eric Deck, Tenley Banik, and Brian Hampton. "Detrital zircon geochronology of quartzite clasts in the Permian Abo Formation, Sacramento Mountains, New Mexico, USA." Mountain Geologist 54, no. 2 (April 2017): 53–68. http://dx.doi.org/10.31582/rmag.mg.54.2.53.
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More than 2500 m of Paleozoic strata, ranging in age from Cambrian to Permian occur in the Sacramento Mountains of New Mexico, making these rocks the largest and most complete exposures of Paleozoic strata in North America. The core of the Sacramento Mountains reveals compressional structures associated with the Pennsylvanian-Permian Ancestral Rocky Mountain orogeny. The Permian Abo Formation is 120–450 m in thickness, and consists of interbedded sandstone, conglomerate, limestone and shale and rests above the Ancestral Rocky Mountain unconformity. U-Pb analysis of detrital zircons extracted from quartzite clasts in basal conglomerates reveal a maximum depositional age of their protolith to be 1110 ± 15 Ma. Most (∼40%) of the detrital zircon age spectrum is Grenville (1000–1300 Ma) in age, with a peak age of 1209 Ma. Midcontinent Granite-Rhyolite (1300–1500 Ma) ages comprise about 33% of the data, and have a peak age of 1431 Ma. Smaller age populations of Yavapai-Mazatzal (1600–1800 Ma; age peak =1676 Ma), Trans-Hudson (1800–2000 Ma; peak age = 1820 Ma), and Archean (>2.5 Ga, age peak = 2819 Ma) also are present. U-Pb detrital zircon ages from these quartzite clasts indicate that they were likely derived from the Proterozoic Lanoria Formation, which is exposed now in the Franklin Mountains >150 km to the south. The Lanoria is identical to the Abo clasts in terms of maximum depositional age and detrital zircon age peaks. The protolith sandstone of these quartzite clasts and quartzites of the Lanoria were derived from the Grenville high-lands of the Llano region of central Texas, and then transported west to the Rodinian continental margin at ∼1110 Ma, where they were eventually buried and metamorphosed to quartzite. These quartzites were subsequently uplifted and eroded during the Ancestral Rocky Mountain orogeny and transported north and west along the Pedernal Uplift to the adjacent Orogrande Basin during the early Permian.
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Zhalov, Holmurod Akimovich. "DISTRIBUTION OF BRYOPHYTES OF AGALYK BASIN (KARATEPA MOUNTAINS OF ZERAVSHAN MOUNTAIN RANGE)." Samara Journal of Science 4, no. 2 (June 15, 2015): 80–82. http://dx.doi.org/10.17816/snv20152123.
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From bryological point of view Zeravshan mountain range remains one of the least studied region. Identification of species composition of true mosses and their ecological-biological peculiarities were not earlier aimed for this region. In the territory of Agalyk basin Karatepa mountains can be divided into four types of substrates where moss species occur: soil, bark of living trees, decayed wood, stones. Characteristics of substrate groups become complicated due to wide range of ecological valency of moss species. Most species select not only one, but several substrates for their settling. During the research period in the soils of Agaliksay basin 20 species were recorded belonging to 13 genera and 10 family. On decayed wood 9 species were recorded belonging to 7 genera and 5 family. On the bark of living trees 15 moss species were recorded belonging to 8 genera and 6 family. Epilyte bryophytes occurred on rocky substrates. On rocky substrates of Agaliksay basin 34 moss species were recorded from 16 genera and 13 family. On the basis of results obtained during the study of substrate groups of mosses in Agaliksay basin, we have conducted comparative analyses of studied substrate groups with the purpose of determining their characteristic features.
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Ishbirdina, L. M., N. I. Fedorov, and A. A. Muldashev. "Geographical and phytocoenotic areas of endemic of the South Urals Delphinium uralense Nevski." Vegetation of Russia, no. 28 (2016): 37–54. http://dx.doi.org/10.31111/vegrus/2016.28.37.
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The geographical and phytocoenotic areas of the endemic of the Southern Urals Delphinium uralense that is a relic species of the ancient Pleistocene steppe were studied. Species is listed in the Red book of the Russian Federation (2008) and the Red Book of the Republic of Bashkortostan (2011). The main part of the geographical area of the investigated species is limited by the Zilair plateau located in the south-western tip of the Ural Mountains, within the Urals fold-block surface. The phytocoenotic area of this species includes the xerophytic communities referring to 2 classes, 3 orders, 4 alliances, 1 suballiance, 2 associations, 1 subassociation, 1 variantand 4 non-ranking communities The formation of the unique complex of xerophytic oak-larch sparse forests and rocky steppes in the southern Urals is linked with the occurrence of the mountainous steppe with larch groves, which were the remnants of the xerophytic mountain landscape —“Pleistocene floristic complex” (Igoshina, 1961, 1963). The enrichment the floristic composition of the complex took place in the late Pleistocene due to following facts: the appearance of rock and mountain-steppe Asian relict species (Ryabinina, 1993), the migration of Eastern Siberian elements to the West, the movement of European species to the East, the formation of the Urals endemic floristic races (Krasheninnikov, 1939). Later, in the Holocene, the Pleistocene floristic complex was enriched by some species of broad-leaved forests (including oak Quercus robur), the penetration ofthe south richsteppe flora, and replenishment of the floristic complex by the Pontic and Sarmatic species (Igoshina, 1961). As a result of mentioned above processes a unique complex of xerophytic rocky mountain steppes and of sparse oak and larch elfin woodswas formed in the Zilair plateau.
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Brooks, B. G. J., A. R. Desai, B. B. Stephens, D. R. Bowling, S. P. Burns, A. S. Watt, S. L. Heck, and C. Sweeney. "Assessing filtering of mountaintop CO<sub>2</sub> mole fractions for application to inverse models of biosphere-atmosphere carbon exchange." Atmospheric Chemistry and Physics 12, no. 4 (February 22, 2012): 2099–115. http://dx.doi.org/10.5194/acp-12-2099-2012.
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Abstract. There is a widely recognized need to improve our understanding of biosphere-atmosphere carbon exchanges in areas of complex terrain including the United States Mountain West. CO2 fluxes over mountainous terrain are often difficult to measure due to unusual and complicated influences associated with atmospheric transport. Consequently, deriving regional fluxes in mountain regions with carbon cycle inversion of atmospheric CO2 mole fraction is sensitive to filtering of observations to those that can be represented at the transport model resolution. Using five years of CO2 mole fraction observations from the Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON), five statistical filters are used to investigate a range of approaches for identifying regionally representative CO2 mole fractions. Test results from three filters indicate that subsets based on short-term variance and local CO2 gradients across tower inlet heights retain nine-tenths of the total observations and are able to define representative diel variability and seasonal cycles even for difficult-to-model sites where the influence of local fluxes is much larger than regional mole fraction variations. Test results from two other filters that consider measurements from previous and following days using spline fitting or sliding windows are overly selective. Case study examples showed that these windowing-filters rejected measurements representing synoptic changes in CO2, which suggests that they are not well suited to filtering continental CO2 measurements. We present a novel CO2 lapse rate filter that uses CO2 differences between levels in the model atmosphere to select subsets of site measurements that are representative on model scales. Our new filtering techniques provide guidance for novel approaches to assimilating mountain-top CO2 mole fractions in carbon cycle inverse models.
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Hartman, Gregory M. D., John J. Clague, René W. Barendregt, and Alberto V. Reyes. "Late Wisconsinan Cordilleran and Laurentide glaciation of the Peace River Valley east of the Rocky Mountains, British Columbia." Canadian Journal of Earth Sciences 55, no. 12 (December 2018): 1324–38. http://dx.doi.org/10.1139/cjes-2018-0015.
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In the past, researchers have disagreed over the maximum extent of the Cordilleran Ice Sheet in the Peace River valley during the Late Wisconsinan. Some workers argued that Cordilleran ice reached beyond the Rocky Mountains and briefly coalesced with the Laurentide Ice Sheet on the westernmost Interior Plains. In contrast, others asserted that Cordilleran ice did not reach beyond the eastern front of the Rocky Mountains. Stratigraphic interpretation of three sections within a Middle Wisconsinan paleovalley and re-examination of a previously published regional stratigraphic framework show that western-sourced ice (likely the Cordilleran Ice Sheet) extended east of the mountain front during the Late Wisconsinan, prior to the incursion of the Laurentide Ice Sheet into the area. This conclusion has implications for Cordilleran Ice Sheet reconstruction and modelling, and provides insight into the interactions between the Cordilleran and Laurentide ice sheets during the last glaciation.
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Janes, Jasmine K., Yisu Li, Christopher I. Keeling, Macaire M. S. Yuen, Celia K. Boone, Janice E. K. Cooke, Joerg Bohlmann, et al. "How the Mountain Pine Beetle (Dendroctonus ponderosae) Breached the Canadian Rocky Mountains." Molecular Biology and Evolution 31, no. 7 (April 22, 2014): 1803–15. http://dx.doi.org/10.1093/molbev/msu135.
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Romme, William H., Dennis H. Knight, and Joseph B. Yavitt. "Mountain Pine Beetle Outbreaks in the Rocky Mountains: Regulators of Primary Productivity?" American Naturalist 127, no. 4 (April 1986): 484–94. http://dx.doi.org/10.1086/284497.
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Chapman, Teresa B., Thomas T. Veblen, and Tania Schoennagel. "Spatiotemporal patterns of mountain pine beetle activity in the southern Rocky Mountains." Ecology 93, no. 10 (October 2012): 2175–85. http://dx.doi.org/10.1890/11-1055.1.
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Scott, Daniel N., and Ellen E. Wohl. "Geomorphic regulation of floodplain soil organic carbon concentration in watersheds of the Rocky and Cascade Mountains, USA." Earth Surface Dynamics 6, no. 4 (November 23, 2018): 1101–14. http://dx.doi.org/10.5194/esurf-6-1101-2018.
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Abstract. Mountain rivers have the potential to retain OC-rich soil and store large quantities of organic carbon (OC) in floodplain soils. We characterize valley bottom morphology, floodplain soil, and vegetation in two disparate mountain river basins: the Middle Fork Snoqualmie in the Cascade Mountains and the Big Sandy in the Wind River Range of the Rocky Mountains. We use this dataset to examine variability in OC concentration between these basins as well as within them at multiple spatial scales. We find that although there are some differences between basins, much of the variability in OC concentration is due to local factors, such as soil moisture and valley bottom geometry. From this, we conclude that local factors likely play a dominant role in regulating OC concentration in valley bottoms and that interbasin differences in climate or vegetation characteristics may not translate directly into differences in OC storage. We also use an analysis of OC concentration and soil texture by depth to infer that OC is input to floodplain soils mainly by decaying vegetation, not overbank deposition of fine, OC-bearing sediment. Geomorphology and hydrology play strong roles in determining the spatial distribution of soil OC in mountain river corridors.
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Lipman, Peter W. "Raising the West: Mid-Cenozoic Colorado-plano related to subvolcanic batholith assembly in the Southern Rocky Mountains (USA)?" Geology 49, no. 9 (June 3, 2021): 1107–11. http://dx.doi.org/10.1130/g48963.1.
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Abstract The Southern Rocky Mountains of Colorado, United States, have the highest regional elevation in North America, but present-day crustal thickness (∼42–47 km) is no greater than for the adjacent, topographically lower High Plains and Colorado Plateau. The chemistry of continental-arc rocks of the mid-Cenozoic Southern Rocky Mountain volcanic field, calibrated to compositions and Moho depths at young arcs, suggests that paleocrustal thickness may have been 20%–35% greater than at present and elevations accordingly higher. Thick mid-Cenozoic Rocky Mountain crust and high paleo-elevations, comparable to those inferred for the Nevadaplano farther west in the United States from analogous volcanic chemistry, could be consistent with otherwise-perplexing evidence for widespread rapid erosion during volcanism. Variable mid-Cenozoic crustal thickening and uplift could have resulted from composite batholith growth during volcanism, superimposed on prior crustal thickening during early Cenozoic (Laramide) compression. Alternatively, the arc–crustal thickness calibration may be inappropriate for high-potassium continental arcs, in which case other published interpretations using similar methods may also be unreliable.
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Cripps, C., and E. Horak. "Checklist and Ecology of the Agaricales, Russulales and Boletales in the alpine zone of the Rocky Mountains (Colorado, Montana, Wyoming) at 3000-4000 m a.s.l." Sommerfeltia 31, no. 1 (February 1, 2008): 101–23. http://dx.doi.org/10.2478/v10208-011-0005-5.
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Checklist and Ecology of the Agaricales, Russulales and Boletales in the alpine zone of the Rocky Mountains (Colorado, Montana, Wyoming) at 3000-4000 m a.s.l.Previously, the Rocky Mountain alpine zone was a mycological blank spot. There have only been a few scattered records of macrofungi from this region and limited number of publications. This alpine survey covers the Beartooth Plateau in Montana/Wyoming for the North-central Floristic Region (lat 45°N) and the Front Range, San Juan Mountains, Sawatch Range for the Southern Floristic Region in Colorado (lat 36°-38°N), and reports over 165 species in 46 genera and 11 families (ca 1 500 collections). It is estimated that over 75% are known arctic-alpine macromycetes and the remainder are Rocky Mountain species. Of these, we estimate that 2-5% are new to science, 75% are new records for this Rocky Mountain alpine zone, and that over half will be new to Colorado or Montana/Wyoming. Approximately 56% are mycorrhizal species associated with Salix reticulata, S. arctica, S. planifolia, S. glauca, Betula nana = B. glandulosa, Dryas octopetala and Polygonum viviparum. Mycorrhizal species that occur with Betula are rare in the Rockies due to a paucity of this host. The most diverse mycorrhizal family is the Cortinariaceae with over 74 species, primarily of Inocybe and Cortinarius. Saprobic genera associate with a diversity of bryophytes or are terrestrial primarily in grassland; macrofungi on woody debris are rare. A greater diversity occurs in southern mountain ranges which are more diverse in geology and habitat. The southern extent of the Rockies at latitudes of 36-38°N likely includes the southernmost extent of certain Arctic-alpine fungi such as Arrhenia auriscalpium for the Northern hemisphere. Macrofungal fruitings are sparse compared to those in maritime arctic-alpine habitats due to a well-defined continental climate with drying winds, low relative humidity, periodic droughts, fire, strong diurnal temperature fluctuations and high elevations of 3 000-4 000 m. This report helps complete distributions of arctic-alpine fungi, and discusses the ecology of individual taxonomic groups in relation to other Arctic-alpine areas.
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Frey, Jennifer K., and Michael T. Calkins. "Habitat Use of the Rocky Mountain Water Shrew in the White Mountains, Arizona." Journal of Fish and Wildlife Management 11, no. 1 (March 24, 2020): 196–209. http://dx.doi.org/10.3996/102019-jfwm-092.
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Abstract The population of Rocky Mountain water shrew Sorex navigator occurring in the White Mountains, Arizona, is isolated, genetically divergent, and of conservation concern. However, little is known about its distribution and habitat use due to difficulty capturing animals during previous surveys. The objectives of this study were to report captures of S. navigator that occurred during a survey for the New Mexico jumping mouse Zapus luteus luteus that expand its known distribution, evaluate habitat of capture sites, report natural history observations, and describe methods for capturing S. navigator. We captured 17 S. navigator at six sites, making this the most successful survey for this population. The records included two new sites and confirmation of the persistence of two historical populations considered extirpated. At the landscape scale, elevation was the best predictor of sites for capture of S. navigator. We captured Rocky Mountain water shrews on small cold-water streams and seeps on saturated soil with high vertical cover of herbaceous plants primarily consisting of sedges Carex. Sherman live traps were ideal for capturing S. navigator, if set appropriately. Given the population's restricted distribution, fragile habitat, and ongoing threats, conservation measures may be warranted.
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Kite, Geoff. "Measuring glacier outflows using a computerized conductivity system." Journal of Glaciology 40, no. 134 (1994): 93–96. http://dx.doi.org/10.3189/s0022143000003841.
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AbstractThe traditional method of calculating glacier outflows by measuring velocities and areas is difficult, inaccurate and sometimes dangerous in fast mountain streams. The salt-dilution method offers a more accurate alternative but, until now, its use has been restricted because of the difficulty of mixing chemical solutions and measuring chemical concentrations in the field. A computer program has been written which uses a laptop microcomputer to control measurements of stream conductivity and which quickly computes the stream flow directly in the field. The development of this method is described and examples are presented of the application of the method for glaciers in the Rocky Mountains and the Coast Mountains of Canada.
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Cruden, D. M., and T. M. Eaton. "Reconnaissance of rockslide hazards in Kananaskis Country, Alberta." Canadian Geotechnical Journal 24, no. 3 (August 1, 1987): 414–29. http://dx.doi.org/10.1139/t87-052.
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Kananaskis Country is situated in the Front Ranges of the Canadian Rockies in southwestern Alberta. Sedimentary rock thrust northeastwards forms mountain ridges that trend northwest–southeast parallel to the major thrust faults. Older, Palaeozoic rocks—mainly limestone and dolomite—form the ridges and peaks. Younger, Mesozoic rocks—sandstones, quartzites, siltstones, shales, conglomerates, and coals—are more easily eroded and form mountain passes and valleys.A reconnaissance mapped 228 rockslides, 8 km2 of rockslide debris and 96 km2 of talus. The largest rockslide exceeds 50 × 106 m3. Rockslides are most probable in the Devonian Palliser Formation, then in the Permo-Pennsylvanian Rocky Mountain Group, Mississippian Rundle Group, Devonian Fairholme Group, Mississippian Banff Formation, and the younger detrital rocks. Rockslides are most probable on dip and overdip slopes, followed by reverse-dip slopes, oblique and strike-dip slopes, and underdip slopes. Large rock masses have not slid on slopes below their basic friction angle, [Formula: see text]The reconnaissance shows that certain facilities in valleys below steep mountain slopes are exposed to rockslide hazards, and provides a guide for the location of new facilities. Analyses of two mountain slopes show that there are large, hypothetical hazards in Kananaskis. Rockslides are likely and could be destructive. Key words: Front Ranges, Rocky Mountains, Alberta, rockslides, hazards.
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Veblen, Thomas T. "Historic range of variability of mountain forest ecosystems: concepts and applications." Forestry Chronicle 79, no. 2 (April 1, 2003): 223–26. http://dx.doi.org/10.5558/tfc79223-2.
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Concepts of historical range of variability (HRV) have taken on an increasingly important role in resource planning and the management of mountain forest ecosystems. This essay draws on examples from the study of the history of disturbance ecology in the Colorado Rocky Mountains and the southern Andes to examine key HRV concepts and their applications. These case studies show that historical perspectives can reduce the chances of major future surprises in ecosystem conditions related to climatic variation, which often overrides many of the effects of management practices. They demonstrate the long-lasting legacy effects of relatively infrequent but severe disturbances in the past that shaped the present landscape and its potential response to future climatic variation. Finally, the case studies illustrate the importance of conducting area-specific research in potential management areas rather than simply extrapolating research findings from studies of historic range of variability of forest ecosystems conducted elsewhere. Key words: climatic variation, disturbance, Rocky Mountains, Andes, Patagonia, Ponderosa pine, landscape, ecosystem management, fire
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Ballesteros Possú, William, James R. Brandle, and Héctor Ramiro Ordóñez. "Carbon storage potential of windbreaks in the United States." Revista de Ciencias Agrícolas 36, E (October 16, 2019): 108–23. http://dx.doi.org/10.22267/rcia.1936e.111.
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In the United States of America, agriculture is performed on large farms of monocultures, affecting ecosystems and making a great contribution to climate change. The carbon storage potential for twelve field windbreak designs containing one-, two- and three-rows and nine farmstead windbreaks encompassing three- to ten-rows of mixed tree species were analyzed in nine regions: Northern Lake States (NLS), Corn Belt (CB), Southern Plains (SP), Delta States (DS), Appalachia (AP), Rocky Mountains North (RMN), Rocky Mountains South (RMS), North East (NE), y Northern Plains (NP), using the US Forest Inventory and Analysis database and allometric equations. Carbon storage potentials for different field windbreak designs across regions ranged from 0.3 Mg C km-1 yr-1 for a single-row small-conifer windbreak in the Northeast region to 5.8 Mg C km-1 yr-1 for a three-row tall-deciduous windbreak in the Appalachia region. Carbon storage potentials for farmstead windbreaks ranged from 0.8 Mg C 300 m-1 yr-1 for a three-row of mixed tree species windbreak in the Rocky Mountain North to 12.7 Mg C 300-1 yr-1 for a ten-row of mixed tree species windbreak in Delta States region.
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Deakin, Samuel, Jamieson C. Gorrell, Jeffery Kneteman, David S. Hik, Richard M. Jobin, and David W. Coltman. "Spatial genetic structure of Rocky Mountain bighorn sheep (Ovis canadensis canadensis) at the northern limit of their native range." Canadian Journal of Zoology 98, no. 5 (May 2020): 317–30. http://dx.doi.org/10.1139/cjz-2019-0183.
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The Canadian Rocky Mountains are one of the few places on Earth where the spatial genetic structure of wide-ranging species has been relatively unaffected by anthropogenic disturbance. We characterized the spatial genetic structure of Rocky Mountain bighorn sheep (Ovis canadensis canadensis Shaw, 1804) in the northern portion of their range. Using microsatellites from 1495 individuals and mitochondrial DNA sequences from 188 individuals, we examined both broad- and fine-scale spatial genetic structure, assessed sex-biased gene flow within the northern portion of the species range, and identified geographic patterns of genetic diversity. We found that broad-scale spatial genetic structure was consistent with barriers to movement created by major river valleys. The fine-scale spatial genetic structure was characterized by a strong isolation-by-distance pattern, and analysis of neighborhood size using spatial autocorrelation indicated gene flow frequently occurred over distances of up to 100 km. However, analysis of sex-specific spatial autocorrelation and analysis of mitochondrial haplotype distributions failed to detect any evidence of sex-biased gene flow. Finally, our analyses reveal decreasing genetic diversity with increasing latitude, consistent with patterns of post-glacial recolonization of the Rocky Mountains.
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Taylor, Peter John, Aubrey Munyai, Ian Gaigher, and Rod Baxter. "Afromontane small mammals do not follow the hump-shaped rule: altitudinal variation in the Soutpansberg Mountains, South Africa." Journal of Tropical Ecology 31, no. 1 (December 8, 2014): 37–48. http://dx.doi.org/10.1017/s0266467414000613.
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Abstract:Altitudinal transects of biodiversity are important to understanding macro-ecological patterns. Hump-shaped altitudinal profiles in species richness are a common pattern in terrestrial small-mammal communities studied previously mostly in New World mountain ranges. Based on capture–mark–recapture live-trapping conducted over four seasons (four nights per session) along an altitudinal transect from 1000 to 1747 m asl on the southern slopes of the Soutpansberg Mountains of northern South Africa, we recorded 12 species of small mammal, including nine rodents, two shrews and one elephant shrew (sengi). Three species of rodent and the sengi dominated the communities whilst six species were recorded with three or fewer captures. Although we found no effect of season, we found a significant linear increase in terrestrial small-mammal richness (but not Simpson's diversity, D) with altitude in the Soutpansberg Mountains located just north of the Tropic of Capricorn in South Africa. This trend could best be explained by an increase in the proportion of rocky cover and a change in vegetation from savanna to grassland. Peak densities of three common rodent species and one common insectivore varied from 10 ha−1 (Elephantulus myurus) to 54 ha−1 (Micaelamys namaquensis) and density showed no significant variation with season. However, density either declined (Aethomys ineptus) or increased (Rhabdomys dilectus and Elephantulus myurus) significantly with altitude; this variation was best explained by the proportion of rocky cover. Seasonal variation had a significant effect on body mass of two rodent species. A review of small-mammal studies from major mountain ranges in Africa and Madagascar found that the hump-shaped pattern is not common. Declines in richness with increasing altitude as well as cases of no significant altitudinal change were the most common patterns noted. Tropical African mountains (including the Soutpansberg with 27 species) have far higher small-mammal diversity than temperate African mountains.
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Kite, Geoff. "Measuring glacier outflows using a computerized conductivity system." Journal of Glaciology 40, no. 134 (1994): 93–96. http://dx.doi.org/10.1017/s0022143000003841.
Full textAbstract:
Abstract The traditional method of calculating glacier outflows by measuring velocities and areas is difficult, inaccurate and sometimes dangerous in fast mountain streams. The salt-dilution method offers a more accurate alternative but, until now, its use has been restricted because of the difficulty of mixing chemical solutions and measuring chemical concentrations in the field. A computer program has been written which uses a laptop microcomputer to control measurements of stream conductivity and which quickly computes the stream flow directly in the field. The development of this method is described and examples are presented of the application of the method for glaciers in the Rocky Mountains and the Coast Mountains of Canada.
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Nixon, D. J., and D. M. Mcclung. "Snow avalanche runout from two Canadian mountain ranges." Annals of Glaciology 18 (1993): 1–6. http://dx.doi.org/10.1017/s0260305500011162.
Full textAbstract:
Field measurements on maximum runout from two different mountain ranges in Canada are presented and compared: the Coast Mountains in British Columbia and the Rocky Mountains. We include a statistical analysis of topographic terrain parameters such as starting zone catchment area, horizontal reach, vertical drop and relevant slope angles. Following McClung and Mears (1991), we derived a dimensionless parameter which is a measure of runout for each avalanche and we found that the runout ratios (defined below) for a given mountain range obey a Gumbel distribution consistent with previous results. In addition, we found that the runout ratios for both mountain ranges have a length-scale dependence which is potentially very important for land-use planning procedures: the mean value of the runout ratio decreases significantly as the horizontal reach increases. Together with data from other mountain ranges, our results show that path length effects will have to be incorporated when using statistical prediction methods for engineering zoning purposes. The runout ratio is defined as the quotient of two lengths, Δx/Xβ, where Δ is the horizontal distance from the 10° point to the maximum runout position, and Xβ is the horizontal distance from the start position to the point where slope angle first declines to 10°.