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2017002963 Carturan, Luca (University of Padova, Department of Land, Environment, Agriculture and Forestry, Padova, Italy); Zuecco, G.; Seppi, R.; Zanoner, T.; Borga, M.; Carton, A. and Dalla Fontana, G. Catchment-scale permafrost mapping using spring water characteristics: Permafrost and Periglacial Processes, 27(3), p. 253-270, illus. incl. geol. sketch maps, charts, 81 ref., September 2016.
This study presents a method for mapping the spatial distribution of mountain permafrost based on the chemical-physical characterisation of spring water in a 36 km2 high-elevation catchment in the Eastern Italian Alps. Water temperature, electrical conductivity and isotopic composition (d2H and d18O) were measured in 45 springs during summer 2007, 2010 and 2012. Existing evidence of permafrost enabled the areas upslope of springs to be classified into two categories of permafrost occurrence (probable permafrost and no permafrost) and used to determine the most suitable tracer for permafrost mapping. Springs from probable permafrost areas have a specific water temperature signature. Spring water temperature was therefore used as a response variable in multiple linear regression, and mean elevation and mean clear sky radiation of spring upslope areas were used as predictors. The multiple regression models were statistically significant and used to map the potential spatial distribution of spring water temperature, which was reclassified into three permafrost categories (probable, possible and improbable). Cross-validation and independent validation by ground surface temperature data provided evidence that the spring water temperature can be used alone for easy and low-cost assessment of the catchment-scale permafrost distribution in similar alpine catchments. Copyright Copyright 2015 John Wiley & Sons, Ltd.
DOI: 10.1002/ppp.1875
2017002964 Milana, Juan Pablo (Universidad Nacional de San Juan, San Juan, Argentina). Molards and their relation to landslides involving permafrost failure: Permafrost and Periglacial Processes, 27(3), p. 271-284, illus. incl. 1 table, 49 ref., September 2016.
Molards are conical-shaped, often symmetrical debris mounds with a distinctive radial grain size gradation, which were first named in the Alps over 100 years ago. Historically, these landforms did not receive much academic attention as they were rarely observed. Today, six different genetic hypotheses can be applied to molards, and the most recent has suggested a link to permafrost failure. The aim of this research was to test the hypothesis that molards result from the failure of permafrost-bearing ground and subsequent thawing of the frozen debris boulders. This hypothesis is tested by: (1) reviewing the known global distribution of molard-bearing mass movements with respect to permafrost distribution; (2) investigating a landslide in the Andes of Argentina that unequivocally relates to permafrost failure; (3) describing and interpreting the external and internal structure of molards, applying sedimentary transport concepts; and (4) reproducing molards by laboratory simulation. The results show that, with few exceptions, molards are produced by melt-out of ground ice in permafrost blocks. In particular, a permafrost source of the mass flow is more certain for landslide deposits that are densely populated by molards. This study serves to reappraise the presence of molards as they could be used to track ground ice loss and potential permafrost degradation in mountainous areas and hence climate change. Copyright Copyright 2015 John Wiley & Sons, Ltd.
DOI: 10.1002/ppp.1878
2017001034 Painter, Scott L. (Oak Ridge National Laboratory, Climate Change Science Institute, Oak Ridge, TN); Coon, Ethan T.; Atchley, Adam L.; Berndt, Markus; Garimella, Rao; Moulton, J. David; Svyatskiy, Daniil and Wilson, Cathy J. Integrated surface/subsurface permafrost thermal hydrology; model formulation and proof-of-concept simulations: Water Resources Research, 52(8), p. 6062-6077, illus., 63 ref., August 2016.
The need to understand potential climate impacts and feedbacks in Arctic regions has prompted recent interest in modeling of permafrost dynamics in a warming climate. A new fine-scale integrated surface/subsurface thermal hydrology modeling capability is described and demonstrated in proof-of-concept simulations. The new modeling capability combines a surface energy balance model with recently developed three-dimensional subsurface thermal hydrology models and new models for nonisothermal surface water flows and snow distribution in the microtopography. Surface water flows are modeled using the diffusion wave equation extended to include energy transport and phase change of ponded water. Variation of snow depth in the microtopography, physically the result of wind scour, is modeled phenomenologically with a diffusion wave equation. The multiple surface and subsurface processes are implemented by leveraging highly parallel community software. Fully integrated thermal hydrology simulations on the tilted open book catchment, an important test case for integrated surface/subsurface flow modeling, are presented. Fine-scale 100 year projections of the integrated permafrost thermal hydrological system on an ice wedge polygon at Barrow Alaska in a warming climate are also presented. These simulations demonstrate the feasibility of microtopography-resolving, process-rich simulations as a tool to help understand possible future evolution of the carbon-rich Arctic tundra in a warming climate. Abstract Copyright (2016), . American Geophysical Union. All Rights Reserved.
DOI: 10.1002/2015WR018427
2017001281 Edwards, Mary (University of Southampton, Department of Geography and Environment, Southampton, United Kingdom); Grosse, Guido; Jones, Benjamin M. and McDowell, Patricia. The evolution of a thermokarst-lake landscape; late Quaternary permafrost degradation and stabilization in Interior Alaska: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 3-14, illus. incl. 1 table, sketch maps, 80 ref., July 2016.
Thermokarst processes characterize a variety of ice-rich permafrost terrains and often lead to lake formation. The long-term evolution of thermokarst landscapes and the stability and longevity of lakes depend upon climate, vegetation and ground conditions, including the volume of excess ground ice and its distribution. The current lake status of thermokarst-lake landscapes and their future trajectories under climate warming are better understood in the light of their long-term development. We studied the lake-rich southern marginal upland of the Yukon Flats (northern interior Alaska) using dated lake-sediment cores, observations of river-cut exposures, and remotely-sensed data. The region features thick (up to 40 m) Quaternary deposits (mainly loess) that contain massive ground ice. Two of three studied lakes formed ~ 11,000-12,000 cal yr BP through inferred thermokarst processes, and fire may have played a role in initiating thermokarst development. From ~ 9000 cal yr BP, all lakes exhibited steady sedimentation, and pollen stratigraphies are consistent with regional patterns. The current lake expansion rates are low (0 to < 7 cm yr-1 shoreline retreat) compared with other regions (~ 30 cm yr-1 or more). This thermokarst lake-rich region does not show evidence of extensive landscape lowering by lake drainage, nor of multiple lake generations within a basin. However, LiDAR images reveal linear "corrugations" (> 5 m amplitude), deep thermo-erosional gullies, and features resembling lake drainage channels, suggesting that highly dynamic surface processes have previously shaped the landscape. Evidently, widespread early Holocene permafrost degradation and thermokarst lake initiation were followed by lake longevity and landscape stabilization, the latter possibly related to establishment of dense forest cover. Partial or complete drainage of three lakes in 2013 reveals that there is some contemporary landscape dynamism. Holocene landscape evolution in the study area differs from that described from other thermokarst-affected regions; regional responses to future environmental change may be equally individualistic.
DOI: 10.1016/j.sedgeo.2016.01.018
2017001280 Oliva, Marc (Universidade de Lisboa, Center for Geographical Studies, Lisbon, Portugal) and Antoniades, Dermot, editors. Limnological processes in permafrost environments: Sedimentary Geology, 340, p. 1-95, illus., July 2016. Individual papers are cited separately.
2017001288 Szopinska, Malgorzata (Gdansk University of Technology, Department of Analytical Chemistry, Gdansk, Poland); Dymerski, Tomasz; Polkowska, Zaneta; Szuminska, Danuta and Wolska, Lidia. The chemistry of river-lake systems in the context of permafrost occurrence (Mongolia, Valley of the Lakes); Part II, Spatial trends and possible sources of organic composition: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 84-95, illus. incl. 3 tables, sketch map, 81 ref., July 2016.
The chemistry of river-lake systems located in Central Mongolia near the southern border of permafrost occurrence has not been well studied. The main aim of this paper is to summarize patterns in water chemistry in supply springs, rivers and lakes in relation to permafrost occurrence, as well as other natural and anthropogenic impacts. The analyses involved water samples taken from two river-lake systems: the Baydrag River-Boon Tsagaan Lake system and the Shargalyuut/Tuyn Rivers-Orog Lake system. Total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) were detected and quantified. Other organic compounds, such as organic halogen compounds, phthalates, and higher alkanes were also noted. The main factors which influence differences in TOC concentrations in the water bodies involve permafrost occurrence, mainly because compounds are released during active layer degradation (in the upper reach of the Tuyn river), and by intensive livestock farming in river valleys and in the vicinity of lakes. In relation to the concentrations of PAHs, high variability between samples (> 300 ng L-1), indicates the influence of thermal water and local geology structures (e.g., volcanic and sedimentary deposits), as well as accumulation of suspended matter in lakes transported during rapid surface runoff events. The monitoring of TOC as well as individual PAHs is particularly important to future environmental studies, as they may potentially reflect the degradation of the environment. Therefore, monitoring in the Valley of the Lakes should be continued, particularly in the light of the anticipated permafrost degradation in the 21st century, in order to collect more data and be able to anticipate the response of river-lake water chemistry to changes in permafrost occurrence.
DOI: 10.1016/j.sedgeo.2016.03.001
2017001287 Szopinska, Malgorzata (Gdansk University of Technology, Department of Analytical Chemistry, Gdansk, Poland); Szuminska, Danuta; Polkowska, Zaneta; Machowiak, Katarzyna; Lehmann, Sara and Chmiel, Stanislaw. The chemistry of river-lake systems in the context of permafrost occurrence (Mongolia, Valley of the Lakes); Part I, Analysis of ion and trace metal concentrations: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 74-83, illus. incl. 1 table, sketch map, 57 ref., July 2016.
This study provides a description of water chemistry in river-lake systems located in central Mongolia, at the borderline of permafrost occurrence. The analysis involved water samples collected from two river-lake systems: Baydrag River-Boon Tsagaan Lake system, and Shargalyuut/Tuyn Rivers-Orog Lake system. In the water samples, ions and trace elements were detected and quantified. Additionally, the parameters of pH, electrical conductivity (SEC), total dissolved solids (TDS) and total organic carbon (TOC) were determined. Principal Component Analysis (PCA) was performed on the sample results. Water chemistry is mostly influenced by geochemical and hydrometeorological processes. Permafrost thawing could increase the concentration of nitrogen (NH4+, NO3-) as well as Na+ and Ca2+, Cl- and SO42-. However, it may also be an effect of other factors such as livestock farming. Seasonal drying out of lakes (e.g., Lake Orog) may also influence water chemistry by deflation of evaporites from exposed lake beds and, at the same time, with lower concentration of chemical compounds in water. The PCA shows that water samples can be divided into two groups. The first group contains lake samples, where water chemistry is shaped by prevailing evaporation processes, whereas the second includes samples from rivers and springs. Water chemistry of the latter is predominantly influenced by geochemical and hydro-meteorological processes.
DOI: 10.1016/j.sedgeo.2016.03.004
2017001286 Szuminska, Danuta (Kazimierz Wielki University, Institute of Geography, Bydgoszcz, Poland). Changes in surface area of the Boon Tsagaan and Orog Lakes (Mongolia, Valley of the Lakes, 1974-2013) compared to climate and permafrost changes: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 62-73, illus. incl. 2 tables, geol. sketch map, 64 ref., July 2016.
The main aim of the study is the analysis of changes in surface area of lake Boon Tsagaan (45°35'N, 99°8'E) and lake Orog (45°3'N, 100°44'E) taking place in the last 40 years in the context of climate conditions and permafrost degradation. The lakes, located in Central Mongolia, at the borderline of permafrost range are fed predominantly by river waters and groundwater from the surrounding mountain areas, characterized by continuous and discontinuous permafrost occurrence - mostly the Khangai. The analysis of the Boon Tsagaan and Orog lake surface area in 1974-2013 was conducted based on satellite images, whereas climate conditions were analysed using the NOAA climate data and CRU dataset. Principal Component Analysis (PCA) was used to study the relationship patterns between the climatic factors and changes in the surface area of the lakes. A tendency for a decrease in surface area, intermittent with short episodes of resupply, was observed in both studied lakes. Climate changes recorded in the analysed period had both direct and indirect impacts on water supply to lakes. Taking into account the results of PCA analysis, the most significant factors include: fluctuation of annual precipitation, increase in air temperature and thickness of snow cover. The extended duration of snow cover in the last decades of the 20th century may constitute a key factor in relation to permafrost degradation.
DOI: 10.1016/j.sedgeo.2016.03.002
2017001284 Weiss, Niels (Stockholm University, Department of Physical Geography, Stockholm, Sweden); Blok, Daan; Elberling, Bo; Hugelius, Gustaf; Jorgensen, Christian Juncher; Siewert, Matthias Benjamin and Kuhry, Peter. Thermokarst dynamics and soil organic matter characteristics controlling initial carbon release from permafrost soils in the Siberian Yedoma region: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 38-48, illus. incl. 3 tables, geol. sketch maps, 42 ref., July 2016.
This study relates soil organic matter (SOM) characteristics to initial soil incubation carbon release from upper permafrost samples in Yedoma region soils of northeastern Siberia, Russia. Carbon (C) and nitrogen (N) content, carbon to nitrogen ratios (C:N), d13C and d15N values show clear trends that correspond with SOM age and degree of decomposition. Incubation results indicate that older and more decomposed soil material shows higher C respiration rates per unit incubated C than younger and less decomposed samples with higher C content. This is important as undecomposed material is often assumed to be more reactive upon thawing. Large stocks of SOM and their potential decomposability, in combination with complex landscape dynamics that include one or more events of Holocene thaw in most of the landscape, are of consequence for potential greenhouse gas release from permafrost soils in the Yedoma region.
DOI: 10.1016/j.sedgeo.2015.12.004
2017000815 Malakhova, V. V. (Russian Academy of Sciences, Siberian Division, Institute of Computational Mathematics, Novosibirsk, Russian Federation) and Golubeva, Ye. N. Otsenka ustoychivosti sostoyaniya merzloty na shel'fe vostochnoy Arktiki pri ekstremal'nom stsenarii potepleniya v XXI v. [Assessment of permafrost stability on continental shelf in the eastern Arctic according to extreme climate warming scenario for the 21st century]: Led i Sneg = Ice and Snow, 56(1), p. 61-72 (English sum.), illus., 29 ref., 2016.
A state of permafrost in the Arctic is the key to understanding whether methane, stored in the permafrost related gas hydrate, can release into the atmosphere. The global warming can lead to destabilization of the submarine permafrost and, thus, cause the methane releasing into the water. The near-bottom water temperature plays a significant role in the current state of the submarine permafrost, because it specifies a depth of thawing of the permafrost. We have numerically simulated evolution of the submarine permafrost on the East Siberia Arctic shelf for the last glacial cycle. In order to estimate a possible state and stability of the submarine permafrost we did carry out a numerical run based on the ICMMG SBRAS the coupled ocean-ice and submarine permafrost model. For the atmosphere forcing, the GFDL CM3 coupled climate model output, simulated under the scenario RCP8.5, was used. The scenario RCP8.5 was used since it predicted the strongest warming by the end of the 21-st century. The GFDL CM3 model, predicting the most pronounced Arctic warming, was also used in order to put the tentative upper boundary on the submarine permafrost degradation in this century. The results obtained show that the offshore permafrost exists across the vast East Siberia shelf. This permafrost occurs continuously but its thickness changes. Thickness of the permafrost within the most part of the East Siberia shelf is estimated 470-590 m when the value of 60 W/m2 was used for the geothermal flux. Our results reveal a certain rising of the bottom layer temperature on the shelf and subsequent penetration of a heat flux into the sediments. However, our results show that even the extreme warming is not sufficient to destabilize the submarine permafrost on the shelf of both, the Laptev Sea and the East Siberian Sea. By the end of the 21st century, upper boundary of the permafrost deepens by value from 1 to 11 m only due to the thermal effects, and by 5-10 m in addition if we take into account the salinity of sediments. However, the depth of the permafrost upper boundary is still smaller than that of the hydrate stability zone. The thickness of the methane hydrate stability zone on the shelf is estimated 770-870 m. Moreover, upper boundary of this zone occurs at a depth of 120-220 m below the sea bottom, which makes the gas hydrates be isolated from the seabed surface by the permafrost layer. The submarine permafrost functions as an impermeable lid and prevents the methane from destroyed gas hydrates.
DOI: 10.15356/2076-6734-2016-1-61-72
2017000634 Ma Wei (Chinese Academy of Sciences, Laboratory of Frozen Soil Engineering, Lanzhou, China) and Chen Tuo. Analysis of permanent deformations of railway embankments under repeated vehicle loadings in permafrost regions: Sciences in Cold and Arid Regions, 7(6), p. 645-653, illus. incl. 2 tables, 21 ref., December 2015.
By large-scale dynamic tests carried out on a traditional sand-gravel embankment at the Beilu River section along the Qinghai-Tibet Railroad, we collected the acceleration waveforms close to the railway tracks when trains passed. The dynamic train loading was converted into an equivalent creep stress, using an equivalent static force method. Also, the creep equation of frozen soil was introduced according to the results of frozen soil rheological triaxial tests. A coupled creep model based on a time-hardening power function rule and the Druker-Prager yield and failure criterion was established to analyze the creep effects of a plain fill embankment under repeated train loads. The temperature field of the embankment in the permafrost area was set at the current geothermal conditions. As a result, the permanent deformation of the embankment under train loading was obtained, and the permanent deformation under the train loads to the total embankment deformation was also analyzed.
DOI: 3724/SP.J.1226.2015.00645
2017005098 Iglovsky, S. A. (Russian Academy of Sciences, Ural Branch, Institute of Ecological Problems of the North, Arkhangelsk, Russian Federation). Anthropogenic changes of permafrost in the European North and their consequences: Water Resources, 41(7), p. 865-871, 34 ref., December 2014.
The anthropogenic changes of permafrost are studied at the key sites in the European North, i.e., Koida Village (Mezen' tundra), Nes' Village (Kanin Peninsula), Shoina Village (Kanin Peninsula), Mezen' Town, Vashutkiny Lakes (Bol'shezemel'skaya tundra), Amderma (Yugorskii Peninsula), and the northern part of Vaigach island. Geocryological characteristics of the sites are provided, and the main types of anthropogenic changes in permafrost conditions are described. Copyright 2014 Pleiades Publishing, Ltd.
DOI: 10.1134/S0097807814070069
2017003379 Lee, Hanna (Uni Research Climate, Bergen, Norway); Swenson, Sean C.; Slater, Andrew G. and Lawrence, David M. Effects of excess ground ice on projections of permafrost in a warming climate: Environmental Research Letters, 9(12), Paper no. 124006, illus. incl. sketch maps, 50 ref., December 2014.
In permafrost soils, 'excess ice', also referred to as ground ice, exists in amounts exceeding soil porosity in forms such as ice lenses and wedges. Here, we incorporate a simple representation of excess ice in the Community Land Model (CLM4.5) to investigate how excess ice affects projected permafrost thaw and associated hydrologic responses. We initialize spatially explicit excess ice obtained from the Circum-Arctic Map of Permafrost and Ground-Ice Conditions. The excess ice in the model acts to slightly reduce projected soil warming by about 0.35 °C by 2100 in a high greenhouse gas emissions scenario. The presence of excess ice slows permafrost thaw at a given location with about a 10 year delay in permafrost thaw at 3 m depth at most high excess ice locations. The soil moisture response to excess ice melt is transient and depends largely on the timing of thaw with wetter/saturated soil moisture conditions persisting slightly longer due to delayed post-thaw drainage. Based on the model projections of excess ice melt, we can estimate spatially explicit gridcell mean surface subsidence with values ranging up to 0.5 m by 2100 depending on the initial excess ice content and the extent of melt. Copyright (Copyright) 2014 IOP Publishing Ltd
DOI: 10.1088/1748-9326/9/12/124006
2017001957 Azharul Hoque, M. (McGill University, Department of Geography, Montreal, QC, Canada) and Pollard, Wayne H. Stability of permafrost dominated coastal cliffs in the Arctic: Polar Science, 10(1), p. 79-88, illus., 52 ref., March 2016.
URL: http://dx.doi.org/10.1016/j.polar.2015.10.004
2017002966 Ishikawa, Mamoru (Hokkaido University, Faculty of Environmental Earth Science, Japan) and Yamkhin, Jambaljav. Formation chronology of Arsain Pingo, Darhad Basin, northern Mongolia: Permafrost and Periglacial Processes, 27(3), p. 297-306, illus. incl. strat. col., 1 table, sketch map, 56 ref., September 2016.
Numerous frost mounds exist on the meander belt and alluvial fan around Arsain Gol River in Darhad basin, northern Mongolia, at the southern fringe of the north-eastern Eurasian permafrost zone. In this environment, abundant water supply and inter-permafrost taliks may allow the development of artesian pressure that leads to groundwater upwelling. The aim of this study was to determine the formation chronology of pingos in this region. The Arsain pingo was drilled to a depth of 35 m to determine the stratigraphy, and data were collected on ground-ice stable isotopic composition, electrical resistivity, ground temperature, and radiocarbon dating and interpreted in conjunction with the chronology of paleo-lake retreat in the basin. A 10 m thick ice core sandwiched between fine-grained lacustrine sediments was identified by drilling and electrical resistivity tomography (ERT). Stable isotope values of ice core samples indicated Rayleigh-type isotope fractionation during the freezing of liquid water. Consequently, closed-system freezing of artesian groundwater appears to be the driving mechanism of pingo formation. Near-surface, segregated ground ice formed from the open-system freezing of meteoric water, concurrent with pingo growth. The lake coverage was extensive until about 10,000 years before present (yr bp), and the growth of the Arsain pingo began after 4500 yr bp, when the paleo-lake was completely drained. The pingo is not presently growing because of a limited groundwater supply to feed the ice core. Copyright Copyright 2015 John Wiley & Sons, Ltd.
DOI: 10.1002/ppp.1877
2017002965 Vasil'chuk, Yurij K. (Lomonosov Moscow State University, Moscow, Russian Federation); Alexeev, Sergey V.; Arzhannikov, Sergey G.; Alexeeva, Ludmila P.; Budantseva, Nadine A.; Chizhova, Julia N.; Arzhannikova, Anastasia V. and Vasil'chuk, Alla C. Lithalsas in the Sentsa River valley, eastern Sayan Mountains, southern Russia: Permafrost and Periglacial Processes, 27(3), p. 285-296, illus. incl. sketch maps, strat. cols., 29 ref., September 2016.
Perennial frost mounds identified as lithalsas occur in the Sentsa River valley of the Eastern Sayan Mountains, Russia. We report the first detailed study of permafrost in this region, based on analysis of the cryostructure and distribution of stable isotopes of oxygen and hydrogen, and ion concentrations from the ice-rich cores of two lithalsas 3-7 m high. Their main cryostructures are reticulate and lenticular, with visible ice contents exceeding 50-60%. The vertical and lateral distribution of d18O and dD values show a step-by-step mechanism of lithalsa growth: in the first stage a large lithalsa formed, and in the second stage a small lithalsa formed. The more negative isotope values of ice in the large lithalsa ice probably resulted from gradual release of isotopically depleted water from the central to peripheral part of the massif during ice segregation in water-saturated fine-grained lake sediments. Minor variations of isotope values suggest intensive recharge of lake-fen and meteoric water supply during freezing and lithalsa growth. Copyright Copyright 2015 John Wiley & Sons, Ltd.
DOI: 10.1002/ppp.1876
2017001063 Lachniet, Matthew S. (University of Nevada at Las Vegas, Department of Geoscience, Las Vegas, NV); Lawson, Daniel E.; Stephen, Haroon; Sloat, Alison R. and Patterson, William P. Isoscapes of d18O and d2H reveal climatic forcings on Alaska and Yukon precipitation: Water Resources Research, 52(8), p. 6575-6586, illus. incl. sketch map, 39 ref., August 2016.
Spatially extensive Arctic stable isotope data are sparse, inhibiting the climatic understanding required to interpret paleoclimate proxy records. To fill this need, we constrained the climatic and physiographic controls on d18O and dD values of stream waters across Alaska and the Yukon to derive interpolated isoscape maps. d18O is strongly correlated to winter temperature parameters and similarity of the surface water line (d2H = 8.0 ´ d18O + 6.4) to the Global Meteoric Water Line suggests stream waters are a proxy for meteoric precipitation. We observe extreme orographic d18O decreases and a trans-Alaskan continental gradient of -8.3 ppm 1000 km-1. Continental gradients are high in coastal zones and low in the interior. Localized d18O increases indicate inland air mass penetration via topographic lows. Using observed d18O/temperature gradients, we show that d18O decreases in a ~24 ka permafrost ice wedge relative to the late Holocene indicate mean annual and coldest quarter temperature reductions of 8.9 ± 1.7°C and 17.2 ± 3.2°C, respectively. Abstract Copyright (2016), . American Geophysical Union. All Rights Reserved.
DOI: 10.1002/2016WR019436
2017006338 Simpson, Jocelyn M. (University of Alaska at Fairbanks, Fairbanks, AK); Darrow, Margaret M.; Huang, Scott L.; Daanen, Ronald P. and Hubbard, Trent D. Investigating movement and characteristics of a frozen debris lobe, south-central Brooks Range, Alaska: Environmental & Engineering Geoscience, 22(3), p. 259-277, illus. incl. 4 tables, sketch maps, 49 ref., August 2016.
Frozen debris lobes (FDLs) are large masses of soil, rock, incorporated organic material, and ice moving down permafrost-affected slopes. In this paper, we focus on FDL-A in the south-central Brooks Range, Alaska, which is an impending geohazard to the Dalton Highway, located just under 40 m away from the highway embankment. We present the results of multi-faceted research, including field-based studies, laboratory testing of soil samples, slope stability analysis, and a geographic information system (GIS) analysis. Subsurface instrumentation indicates that major movement of FDL-A occurs in a shear zone 20.6 to 22.8 m below the ground surface, with temperature-dependent internal flow as a secondary movement mechanism. Surface measurements show an overall average rate of movement of 1.2 cm per day, which is an increase over historic rates. The slope stability analysis required a back analysis to determine soil strength parameters at failure, resulting in cohesion values between 43 and 53 kPa and friction angles between 10° and 16°. The modeling results indicated a high sensitivity to pore-water pressure and cohesion. This is critical since the melting of massive ice and thawing of frozen soil will increase pore-water pressure and lower shear strength, resulting in the acceleration of FDL-A towards the Dalton Highway. The GIS analysis also provided insight into the movement and instability of FDL-A and provided groundwork for a GIS protocol for examining catchment and lobe features of all FDLs along the highway corridor.
DOI: 10.2113/gseegeosci.22.3.259
2017001282 Coulombe, Olivier (Universite Laval, Centre d'etudes Nordiques, Quebec City, QC, Canada); Bouchard, Frederic and Pienitz, Reinhard. Coupling of sedimentological and limnological dynamics in subarctic thermokarst ponds in northern Québec (Canada) on an interannual basis: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 15-24, illus. incl. 2 tables, sketch map, 60 ref., July 2016.
Landscapes are changing at fast rates in subarctic regions due to recent climate warming and related permafrost thaw. As a consequence, thermokarst lakes and ponds are forming and their properties are changing rapidly. Here, we report on the interannual (2012-2014) variability of sedimentological and limnological conditions in a recently formed thermokarst pond in discontinuous permafrost terrain in Northern Quebec, and we discuss various aspects of pond sedimentation processes. Sediment samples from collecting traps and a short core were analyzed for particle size, organic matter content and geochemical composition, as well as 14C dating of a peat sample from the core. Results reveal the preponderance of silts containing 2 to 13% organic matter and an age of 1825-1950 cal. yr. BP for the peat sample. A hypoxic hypolimnion formed in the pond during the short summers. Apparent sedimentation rates (up to 5.5 mm/d) varied in relation to local meteorological conditions and snow cover. The results also reveal major parameters associated with sediment composition, most notably dissolved oxygen in the water column, sampling depth and the year of sampling. Microplankton (20-200 mm) is likely the main source of organic matter, which represents up to 10 to 13% of sediment trap samples, considering its size matching a major grain size mode (44.9-59.0 mm). Using sedimentation rates and an estimation of long-term sediment compaction, the pond's "life span" was calculated at 370 to 600 years. This represents a baseline for the general understanding of the development of young (15-20 years) subarctic thermokarst ponds overlying impermeable soils, and provides an approximate time frame for the potential response of such systems to climate change impacts on northern landscapes.
DOI: 10.1016/j.sedgeo.2016.01.012
2017001283 Farquharson, Louise (University of Alaska at Fairbanks, Department of Geoscience, Fairbanks, AK); Anthony, Katey Walter; Bigelow, Nancy; Edwards, Mary and Grosse, Guido. Facies analysis of yedoma thermokarst lakes on the northern Seward Peninsula, Alaska: in Limnological processes in permafrost environments (Oliva, Marc, editor; et al.), Sedimentary Geology, 340, p. 25-37, illus. incl. 4 tables, sketch map, 77 ref., July 2016.
Thermokarst lakes develop as a result of the thaw and collapse of ice-rich, permanently frozen ground (permafrost). Of particular sedimentological importance are thermokarst lakes forming in late Pleistocene icy silt (yedoma), which dramatically alter the land surface by lowering surface elevation and redistributing upland sediment into lower basins. Our study provides the first description of yedoma thermokarst lake sedimentology based on the cross-basin sampling of an existing lake. We present lake sediment facies descriptions based on data from sediment cores from two thermokarst lakes of medium depth, Claudi and Jaeger (informal names), which formed in previously non thermokarst-affected upland yedoma on the northern Seward Peninsula, Alaska. We identify four prominent facies using sedimentological, biogeochemical, and macrofossil indicators: a massive silt lacking aquatic macrofossils and other aquatic indicators situated below a sub-lacustrine unconformity (Facies 1); two basal deposits: interbedded organic silt and chaotic silt (Facies 2-3); and a silt-rich mud (Facies 4). Facies 1 is interpreted as yedoma that has thawed during lake formation. Facies 3 formed adjacent to the margin due to thaw and collapse events from the lake shore. Material from Facies 3 was reworked by wave action to form Facies 2 in a medium energy margin environment. Facies 4 formed in a lower energy environment toward the lake basin center. This facies classification and description should enhance our ability (i) to interpret the spatial and temporal development of lakes and (ii) to reconstruct long-term patterns of landscape change.
DOI: 10.1016/j.sedgeo.2016.01.002
2017002960 Scapozza, Cristian (University of Applied Sciences and Arts of Southern Switzerland, Canobbio, Switzerland). Evidence of paraglacial and paraperiglacial crisis in alpine sediment transfer since the last glaciation (Ticino, Switzerland): Quaternaire (Paris), 27(2), p. 139-155 (French sum.), illus. incl. strat. cols., 10 tables, sketch maps, 56 ref., June 2016.
The "paraglacial" and "paraperiglacial" concepts were introduced in the second half of 20th Century for describe processes, landforms and deposits directly conditioned by deglaciation (paraglacial), respectively by permafrost degradation (paraperiglacial). They represents theoretical models describing the transition from glacial to periglacial, or more generally non glacial conditions (paraglacial model), and from periglacial to temperate conditions (paraperiglacial model). Evidences of sediment transfer conditioned by these processes were described in particular in the Arctic and Subarctic domains. These evidences are less generalised in the Alps and they consider rarely both concepts, integrating periglacial landforms and deposits in source to sink sediment transfer in a single catchment. Here we present evidences of para(peri)glacial sedimentary crises by quantifying sediment transfer from the periglacial zone to the delta in Lake Maggiore for the Ticino River catchment (southern Swiss Alps). Compilation and revision of chronological data, the assessment of sedimentation rates in the Ticino Valley, of progradation rates of the Ticino River delta and of rockwall erosion rates in the periglacial zone, allowed empirical models of sediment transfer to be produced. These models highlights significant high sedimentation rates in the valley floor during the beginning of the deglaciation, and significant rates of rockwall erosion during periods of intense temperature warming and intense permafrost degradation (such as at the beginning of Bolling and during the Preboreal), showing a very good correspondence with paraglacial and paraperiglacial theoretical models. Sediment transfer evolution during the entire Lateglacial and the first half of Holocene in the southern Swiss Alps may then be explained by a combination of a paraglacial erosion phase related to the deglaciation and of two paraperiglacial erosion phases related with significant periods of temperature warming during the Bolling/Allerod and the first part of the Holocene.
2017000636 Chang Xiaoli (Hunan University of Science and Technology, Xiangtan, China); Jin Huijun; Zhang Yanlin and Sun Haibin. Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains, northeastern China: Sciences in Cold and Arid Regions, 7(6), p. 666-674, illus. incl. 4 tables, sketch map, 23 ref., December 2015.
Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the western flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7-8.2°C higher than the mean annual air temperatures recorded at the Gen'he Weather Station. The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.
DOI: 10.3724/SP.J.1226.2015.00666
2017005099 Yastrebov, A. A. (Russian Academy of Sciences, Sergeev Institute of Environmental Geoscience, Moscow, Russian Federation) and Mamaev, Yu. A. Goals of geoenvironmental assessment of groundwater conditions in the Eocene-Quaternary aquifer in the Yamal-Nenets autonomous district in the context of the development of hydrocarbon deposits: Water Resources, 41(7), p. 872-875, illus. incl. 1 table, sketch map, 7 ref., December 2014.
Regional regularities in the spatial variations of permafrost conditions in the Yamal-Nenets Autonomous District, i.e., permafrost massif structure, cryogenic processes, and the hummock-depression relief they create, control the areal trend in runoff characteristics of Eocene-Quaternary aquifer system and migration of pollutants in the region. The assessment of geosystem tolerance to technogenic impact with global climate warming and permafrost degradation taken into account should be based on water balance calculations taking into consideration the depth and capacity parameters of water objects. Copyright 2014 Pleiades Publishing, Ltd.
DOI: 10.1134/S0097807814070112
2017003266 Godin, Etienne (Université de Montréal, Department of Geography, Montreal, QC, Canada); Fortier, Daniel and Coulombe, Stéphanie. Effects of thermo-erosion gullying on hydrologic flow networks, discharge and soil loss: Environmental Research Letters, 9(10), Paper no. 105010, illus. incl. sketch maps, 31 ref., October 2014.
Thermo-erosion gullies in continuous permafrost regions where ice-wedge polygons are widespread contribute and change the drainage of periglacial landscapes. Gullying processes are causing long-term impacts to the Arctic landscape such as drainage network restructuring, permafrost erosion, sediment transport. Between 2009 and 2013, 35 gullies were mapped in a polygon terrace in the valley of the Glacier C-79 on Bylot Island, Nunavut (Canada), one of which was monitored for its hydrology. A gully (R08p) initiated in 1999 in a low-center polygon terrace. Between 1999 and 2013, 202 polygons over a surface of 28 891 m2 were breached by gullying. Overall, 1401 polygons were similarly breached on the terrace in the valley before 2013. R08p is fed by a 1.74 km2 watershed and the hydrological regime is characterized by peak flows of 0.69 m3 s-1 and a cumulative volume of 229 662 m3 for 2013. Historic aerial photography from 1972 and recent field surveys showed a change in the paths of water tracks and an increase in channelized flow in the gully area from none to 35% of the overall flow path of the section. The overall eroded area for the studied gullies in the valley up to 2013 was estimated at 158 000 m2 and a potential volume close to 200 000 m3. Gullying processes increased drainage of wetlands and the hydrological connectivity in the valley, while lowering residence time of water near gullied areas. Copyright (Copyright) 2014 IOP Publishing Ltd
DOI: 10.1088/1748-9326/9/10/105010
2017003127 Lupachev, A. V. (Russian Academy of Sciences, Institute of Physicochemical and Biological Problems of Soil Science, Pushchino, Russian Federation) and Abakumov, E. V. Soils of Marie Byrd Land, West Antarctica: Eurasian Soil Science, 46(10), p. 994-1006, 49 ref., October 2013. Based on Publisher-supplied data.
Soils of Marie Byrd Land-one of the remotest and difficultly accessible regions of Antarctica-were investigated in the area of the mothballed Russkaya station located to the south of 74° S. Despite the extremely severe wind regime (the average wind velocity is 13 m/s, and the maximum wind velocity is up to 60 m/s), the projective cover of vegetation in the area of the station averages 25-40% and reaches 60-80% in some places. The phenomena of physical weathering of the bedrock-exfoliation, stone pavements, residual rocks exposed by wind (hoodoos), and others-are clearly manifested. In most of the described soils, normal organic and organomineral horizons are absent. The soil profiles represent the mixture of the residues of mosses and lichens and the gravelly eluvium. The fine earth material is blown out of the surface horizons by strong winds; its residual accumulation takes place in the middle and lower parts of the profiles. The classification position of these soils is open to argument; they are close to Petrozems and Lithozems. Most of the profiles are underlain by the massive or slightly disintegrated bedrock with dry permafrost at a depth of 20 to 50 cm. Soils with dry permafrost comprise about 75% of the surveyed area. In separate loci in the depressions of the local mesorelief and on gentle slopes, the soils with clearly expressed cryoturbation features are developed; their profiles are underlain by the ice-rich permafrost and compose about 15% of the surveyed area. Anthropogenically disturbed soils and soils polluted with petroleum hydrocarbons, heavy metals, and other pollutants occupy about 10% of the surveyed area. Copyright 2013 Pleiades Publishing, Ltd.
DOI: 10.1134/S1064229313100049
2017002423 Ning Fulong (China University of Geosciences, School of Engineering, Wuhan, China); Wu Nengyou; Li Shi; Zhang Ke; Yu Yibing; Liu Li; Sun Jiaxin; Jiang Guosheng; Sun Changyu and Chen Guangjin. Estimation of in-situ mechanical properties of gas hydrate-bearing sediments by well-logging: Shiyou Kantan yu Kaifa = Petroleum Exploration and Development, 40(4), p. 507-512, (Chinese) (English sum.), illus., 27 ref., August 2013.
The mechanical properties of gas-hydrate-bearing sediments (GHBS) in the ocean and in permafrost were estimated using log data from Well SH7 in the South China Sea and Well Mount Elbert in the permafrost of Alaska's North Slope using conventional oil and gas reservoir methods, and these results were compared to other tests and calculations. The correlations between mechanical parameters and log velocities used in the conventional oil and gas industry can provide reasonable strength parameters for oceanic GHBS, such as cohesion, internal frictional angle, tensile strength, and shear strength. However, the estimations of the shale content in oceanic GHBS, the internal frictional angle of permafrost GHBS, and elastic parameters such as Young's modulus and the bulk modulus for both oceanic and permafrost GHBS have significant errors. In the future, more effort should be put into building suitable relationships between mechanical parameters and velocities, or more accurate correlations between mechanical parameters and hydrate saturation. This way, with the addition of velocities and hydrate saturations from well-logging, the mechanical properties of GHBS can be more accurately evaluated.
DOI: 10.11698/PED.2013.04.19
2017004691 Tsuji, Takeshi (Kyushu University, International Institute for Carbon-Neutral Energy Research, Fukuoka, Japan); Ikeda, Tatsunori; Johansen, Tor Arne and Ole Ruud, Bent. Using seismic noise derived from fluid injection well for continuous reservoir monitoring: Interpretation (Tulsa), 4(4), p. SQ1-SQ11, illus. incl. sects., sketch map, 44 ref., November 2016.
To construct a reliable and cost-effective monitoring system for injected CO2 in carbon capture and storage projects, we have considered a seismic monitoring approach using seismic noise from a fluid injection well. The passive seismic interferometry continuously monitors injected CO2, enabling the detection of associated accidental incidents (e.g., CO2 leakage). We have applied three approaches: (1) crosscorrelation, (2) crosscoherence, and (3) deconvolution, to the passive seismometer data acquired during a fluid-injection experiment in Svalbard in the Norwegian Arctic. The crosscoherence approach enabled the construction of shot gathers similar to active-source data. Reflectors from the reservoir could be identified on common-midpoint (CMP) gathers constructed via seismic interferometry, and seismic velocity could be estimated from the time-lapse CMP gathers. High-frequency noise from fluid injection operations and low-amplitude background ambient noise were suitable for reconstructing virtual seismic data. However, we clearly found that the time variation characteristics of the noise influenced monitoring results, and thus the stable part of the noise should be used for monitoring. We further applied surface-wave analysis to the virtual shot gathers derived from seismic interferometry and investigated variations in S-wave velocity structure in a shallow formation. We observed clear time variations in seismic velocity in the shallow part of permafrost regions. The information derived from the surface-wave analysis is useful in evaluating the influence of shallow formations on monitoring results of deep reservoirs.
DOI: 10.1190/INT-2016-0019.1
2017000873 Caliskan, Onur (Ankara Universitesi, Egitim Bilimleri Fakultesi, Ankara, Turkey). Karcal daglari kaya buzulu olusumlari [Formations of rock glaciers in the Karcal Mountains; discussion]: Yerbilimleri, 36(3), p. 163-170 (English sum.), illus. incl. 1 table, 14 ref., December 2015. For reference to original see Dede, V., Cicek, I., and Uncu, L., Bulletin for Earth Sciences, Vol. 36(2), p. 61-80, 2015.
This paper is aimed at criticizing the research which was published in Yerbilimleri (Volume 36, Issue 2, pages 61-80) and entitled Formations of Rock Glaciers in Karcal Mountains. The researchers suggested that the landforms are mostly periglacial features although the former studies mentioned that the same landforms are glacial formations in the highlands of Karcal Mountains. The morphogenesis and environment of these landforms need to be discussed in details. Although debris-covered glaciers and ice core rock glaciers have similar origins, they reflect different processes and dynamics. Different processes and dynamics lead to different formations. Another of the discussion points of the paper is the classification of the rock glaciers. The physiographic changes of the adjacent glacier valleys which cause one of the rock glacier's formation as permafrost creep and the other's as glacier ice core are very significant. The causes of formation of two different types of rock glaciers a few meters apart from each other have to be determined objectively.
2017002967 Hrbacek, Filip (Masaryk University, Department of Geography, Brno, Czech Republic); Laska, Kamil and Engel, Zbynek. Effect of snow cover on the active-layer thermal regime; a case study from James Ross Island, Antarctic Peninsula: Permafrost and Periglacial Processes, 27(3), p. 307-315, illus. incl. 2 tables, sketch map, 31 ref., September 2016.
The response of active-layer thickness and the ground thermal regime to climatic conditions on the Ulu Peninsula (James Ross Island, northeastern Antarctic Peninsula) in 2011-13 is presented. The mean air temperature over this period was -8.0°C and ground temperature at 5 cm depth varied from -6.4°C (2011-12) to -6.7°C (2012-13). The active-layer thickness ranged between 58 cm (January 2012) and 52 cm (February 2013). Correlation analyses indicate that air temperature affects ground temperature more significantly on snow-free days (R2 = 0.82) than on snow cover days (R2 = 0.53). Although the effect of snow cover on the daily amplitude of ground temperature was observable to 20 cm depth, the overall influence of snow depth on ground temperature was negligible (freezing n-factor of 0.95-0.97). Copyright Copyright 2015 John Wiley & Sons, Ltd.
DOI: 10.1002/ppp.1871
2017002702 Liu Guangsheng (Xiamen University of Technology, College of Environmental Science and Engineering, Fujian, China) and Wang Genxu. Influence of short-term experimental warming on heat-water processes of the active layer in a swamp meadow ecosystem of the Qinghai-Tibet Plateau: Sciences in Cold and Arid Regions, 8(2), p. 125-134, illus. incl. 3 tables, 32 ref., April 2016.
Climate change is now evident in the Qinghai-Tibet Plateau (QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers (OTC) and the control manipulations were collected over a complete year. The results show that annual (2008) air temperatures of OTC-1 and OTC-2 were 6.7°C and 3.5°C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.
DOI: 10.3724/SP.J.1226.2016.00125
2017004553 Li Zongxing (Chinese Academy of Sciences, Cold and Arid Region Environment and Engineering Research Institute, Lanzhou, China); Qi Feng; Wang, Q. J.; Song, Yong; Li Hongyi and Li Yongge. The influence from the shrinking cryosphere and strengthening evapotranspiration on hydrologic process in a cold basin, Qilian Mountains: Global and Planetary Change, 144, p. 119-128, illus. incl. 1 table, sketch map, 95 ref., September 2016. Includes appendices.
Under a warming climate, the cryosphere shrinking is accelerating and the evapotranspiration is strengthening, which have caused the spatial and temporal changes of water resources and water cycle in inland river basins. With a vast area of 1.0 ´ 104 km2 and an annual average evapotranspiration of 515 mm, the influence from recycling moisture to precipitation and the contribution from cryosphere meltwater to runoff have been quantified in source region of Heihe river basin at the central Qilian Mountains, where 365 glaciers locate within an area of 77.22 km2, whiles frozen soil accounts for 80% of the region. Results indicated that frozen soil meltwater and glacier snow meltwater have contributed by 28% and 7%, on average, to the outlet river water in the basin, respectively. It was founded that evaporation and transpiration moisture were responsible for 10% and 17%, on average, of local precipitation, respectively. These findings provide new progresses on isotopic hydrology of cold basin, which will strengthen further understanding on the role of frozen soil meltwater and local moisture recycling in the water cycle for inland river basins.
DOI: 10.1016/j.gloplacha.2016.06.017
2017002718 Izumiyama, Hiroaki (Kyoto University, Graduate School of Engineering, Kyoto, Japan); Tsutsumi, Daizo and Fujita, Masaharu. Estimation of sediment production from weathered bedrock in different lithology due to freeze-thaw action: Sabo Gakkaishi = Journal of the Japan Society of Erosion Control Engineering, 68(5), p. 10-20, (Japanese) (English sum.), illus. incl. 3 tables, 17 ref., January 2016.
The prediction of sediment production by freeze-thaw action is important for preventing sediment-related disasters and managing river environments. This study conducted a freeze-thaw experiment to investigate the destruction mode of various types of weathered bedrock (representing some of the many types of bedrock in Japan) and to develop destruction models for estimating sediment production. The experiment was conducted on bedrock samples of weathered granite (WGr), weathered granite porphyry (WGp), weathered shale (WS), weathered sandstone (WSa), and weathered rhyolite (WR). Freeze-thaw cycles caused the bedrock samples to increase in porosity and decrease in weight. When the porosities of WGr, WGp, and WS became greater than 0.43, 0.1, and 0.27, respectively, small pieces started to detach from the main sample bodies. Freezing and thawing caused only slight increases in the porosities of WSa and WR and in the production of fine sediment from their surfaces. During one freeze-thaw cycle, WSa and WR produced sediment amounts equivalent to depths of less than 1.0 and 0.2 mm, respectively. It is assumed that these depths are equivalent to the rock particle size. Using the experimental results, two simple destruction models were developed. A model was applied to WGr, WGp and WS. In this model, it was assumed that the porosity increased at a certain rate for each freeze-thaw cycle. When the porosity was greater than the threshold value, the weathered bedrock decomposed to sediment. An alternative model was applied to WSa and WR. In this case it was assumed that sand particles--the size of which was determined by the constituents of the weathered bedrock--were produced with each freeze-thaw cycle. Using this model, we performed a numerical simulation, and estimated the rate of sediment production. The simulation results were in good agreement with measured data.
2017003509 Tan, Zeli (Purdue University, Purdue Climate Change Research Center, West Lafayette, IN) and Zhuang, Qianlai. Arctic lakes are continuous methane sources to the atmosphere under warming conditions: Environmental Research Letters, 10(5), Paper no. 054016, illus. incl. 1 table, sketch map, 55 ref., May 2015.
Methane is the second most powerful carbon-based greenhouse gas in the atmosphere and its production in the natural environment through methanogenesis is positively correlated with temperature. Recent field studies showed that methane emissions from Arctic thermokarst lakes are significant and could increase by two- to four-fold due to global warming. But the estimates of this source are still poorly constrained. By using a process-based climate-sensitive lake biogeochemical model, we estimated that the total amount of methane emissions from Arctic lakes is 11.86 Tg yr-1, which is in the range of recent estimates of 7.1-17.3 Tg yr-1 and is on the same order of methane emissions from northern high-latitude wetlands. The methane emission rate varies spatially over high latitudes from 110.8 mg CH4 m2 day-1 in Alaska to 12.7 mg CH4 m-2 day-1 in northern Europe. Under Representative Concentration Pathways (RCP) 2.6 and 8.5 future climate scenarios, methane emissions from Arctic lakes will increase by 10.3 and 16.2 Tg CH4 yr-1, respectively, by the end of the 21st century. Copyright (Copyright) 2015 IOP Publishing Ltd
DOI: 10.1088/1748-9326/10/5/054016
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2017003291 Gao Siru (Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, State Key Laboratory of Frozen Soil Engineering, Lanzhou, China); Wu Qingbai; Zhang Zhongqiong; Hou Yandong and Wang Qian. Multiple time scale characteristics of permafrost temperature variations along the Qinghai-Xizang Highway: in Quaternary of east Asia and the western Pacific; Part 2 (Chen, Min-Te, editor; et al.), Quaternary International, 349, p. 178-186, illus. incl. 4 tables, sketch map, 32 ref., October 28, 2014. Meeting: Taiwanese Quaternary Research Group biennial conference, Jan. 23-24, 2013, Kaohsiung, Taiwan.
Temperature is an important dynamic attribute of permafrost, but analysis only in the time domain ignores important information in the frequency domain. A combined time-frequency analysis provides a deeper understanding of temperature variations, revealing the response of warm and cold permafrost to climate change under both embankments and natural ground surfaces. Using 17 years of semimonthly permafrost temperature data from boreholes below natural ground surfaces and embankments in warm and cold permafrost, multiple time scale characteristics of permafrost temperature were analyzed via wavelet transformation. The results show that permafrost temperatures have multiple time scale characteristics. Significant changes to all the main periods were observed near the permafrost table. The response of permafrost to climate change under embankments varied significantly for warm and cold permafrost. Trends for permafrost temperature were forecast using large-scale periods of variation in permafrost temperature. Such forecasts have direct significance for analysis of engineering stability and treatment of roadbed damage in cold regions. Abstract Copyright (2014) Elsevier, B.V.
DOI: 10.1016/j.quaint.2014.06.047
2017002129 Istomin, Kirill V. (Russian Academy of Sciences, Ural Branch, Institute of Language, Literature and History, Syktyvkar, Russian Federation) and Habeck, Joachim Otto. Permafrost and indigenous land use in the Northern Urals; Komi and Nenets reindeer husbandry: in ISAR-4/ICARPIII, science symposium of ASSW2015 (Wadhams, Peter, editor; et al.), Polar Science, 10(3), p. 278-287, illus. incl. sketch maps, 53 ref., September 2016. Meeting: 4th international symposium for Arctic science and the 3rd international conference for Arctic research planning, the science symposium of Arctic Science Summit Week 2015 (ISAR-4/ICARPIII), April 23-30, 2015, Toyama, Japan.
URL: http://dx.doi.org/10.1016/j.polar.2016.07.002
2017002131 Maslakov, Alexey (Lomonosov Moscow State University, Faculty of Geography, Moscow, Russian Federation) and Kraev, Gleb. Erodibility of permafrost exposures in the coasts of eastern Chukotka: in ISAR-4/ICARPIII, science symposium of ASSW2015 (Wadhams, Peter, editor; et al.), Polar Science, 10(3), p. 374-381, illus. incl. sketch map, 5 tables, sect., 44 ref., September 2016. Meeting: 4th international symposium for Arctic science and the 3rd international conference for Arctic research planning, the science symposium of Arctic Science Summit Week 2015 (ISAR-4/ICARPIII), April 23-30, 2015, Toyama, Japan.
URL: http://dx.doi.org/10.1016/j.polar.2016.04.009
2017002132 Takakura, Hiroki (Tohoku University, Center for Northeast Asian Studies, Kawauchi, Japan). Limits of pastoral adaptation to permafrost regions caused by climate change among the Sakha people in the middle basin of Lena River: in ISAR-4/ICARPIII, science symposium of ASSW2015 (Wadhams, Peter, editor; et al.), Polar Science, 10(3), p. 395-403, illus. incl. sketch maps, chart, 43 ref., September 2016. Meeting: 4th international symposium for Arctic science and the 3rd international conference for Arctic research planning, the science symposium of Arctic Science Summit Week 2015 (ISAR-4/ICARPIII), April 23-30, 2015, Toyama, Japan.
URL: http://dx.doi.org/10.1016/j.polar.2016.04.003
2017003292 Luo Dongliang (Chinese Academy of Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, State Key Laboratory of Frozen Soils Engineering, Lanzhou, China); Jin Huijun; Jin Rui; Yang Xingguo and Lu Lanzhi. Spatiotemporal variations of climate warming in northern northeast China as indicated by freezing and thawing indices: in Quaternary of east Asia and the western Pacific; Part 2 (Chen, Min-Te, editor; et al.), Quaternary International, 349, p. 187-195, illus. incl. 3 tables, sketch maps, 26 ref., October 28, 2014. Meeting: Taiwanese Quaternary Research Group biennial conference, Jan. 23-24, 2013, Kaohsiung, Taiwan.
As the thermal state of the upper boundary conditions of the soil layer, ground surface and air temperatures sensitively indicate the heat transferring process between atmosphere and land surface. Due to the combined effects of high latitude and elevation, northern northeast (NNE) China is the second largest permafrost region in China. Based on the daily ground surface and air temperatures at 21 selected stations in NNE China, the Mann-Kendall test and Sen's slope estimate were used to detect changes in the mean annual ground surface temperature (MAGST), mean annual air temperature (MAAT), annual ground surface freezing index (GFI), annual air freezing index (AFI), annual ground surface thawing index (GTI), annual air thawing index (ATI), and surface offset of MAGST-MAAT for the period between 1972 and 2005. The results show a significant warming in NNE China during the past three decades. The MAGST and MAAT averaged 0.72 and -0.50°C, with mean increasing rates of 0.61 and 0.72°C/10y, respectively. The lowest MAGST and MAAT were observed in the northernmost and middle parts of the Da Xing'anling Mountains. The multiyear average GFI is 2822.1 °C/y with a range between 1827.6 and 3919.6 DGDd. The multiyear average AFI is 2688.8 °C/y with a range between 1729.5 and 3606.1 °C·d. Over the same period, the multiyear average GTI ranged between 2451.8 and 3705.5 °C·d, with an average of 2514.0 °C/y, and the multiyear average of ATI ranged from 1902.7 to 2990.1 °Dd, with an average of 2508.3 °C. Trend analyses show a significant decline in annual GFI (-13.5 °C·d/y) and annual AFI (-13.4 °Dd/y), and a significant increase in annual GTI (9.96 °C·d/y) and annual ATI (8.71 °C·d/y). The most pronounced warming has occurred in sporadic permafrost regions of NNE China. However, in continuous permafrost, and discontinuous permafrost regions with extensive presence of taliks, such as at Ta'he and Xinlin stations, no significant trend is detected. Study of the variations of freezing and thawing indices may provide some implications of spatiotemporal changes in the thermal regimes of active layer and permafrost soils, and facilitate better understanding of cold environment changes in permafrost regions of Northeast China. Abstract Copyright (2014) Elsevier, B.V.
DOI: 10.1016/j.quaint.2014.06.064
2017003308 Li Long (Northwest Normal University, College of Geography and Environment Sciences, Lanzhou, China); Li Jing; Yao Xiaojun; Luo Jing; Huang Yongsheng and Feng Yaya. Changes of the three holy lakes in recent years and quantitative analysis of the influencing factors: in Quaternary of east Asia and the western Pacific; Part 2 (Chen, Min-Te, editor; et al.), Quaternary International, 349, p. 339-345, illus. incl. 2 tables, sketch map, 39 ref., October 28, 2014. Meeting: Taiwanese Quaternary Research Group biennial conference, Jan. 23-24, 2013, Kaohsiung, Taiwan.
Namco Lake, Yamzho Yumco Lake, and Mapam Yamco Lake are the "three holy lakes" of Tibet. Based on the topographic map of 1970 and the Landsat TM/ETM + remote sensing images of 1970 and from 1990 to 2012, satellite altimetry data, observed data from meteorological stations, and the changes of the "three holy lakes" in area, water level and water storage, the lake status and causes of the changes have been analyzed in a comparative manner. From 1970 to 2012, Namco Lake rapidly expanded in area, Yamzho Yumco Lake sharply declined, and Mapam Yamco Lake showed a slight decline with no great changes. The increase in precipitation was the main reason for the expansion of Namco Lake from 1970 to 1998, but the increase in glacial meltwater caused by temperature rise, and the decrease in evaporation from the lake surface, are the main reasons for the expansion and water storage increase of Namco Lake after 1998. Yamzho Yumco Lake significantly expanded from 1991 to 2004 mainly because the evaporation was limited, and shrank after 2004 because of the decrease in precipitation and the increase in evaporation. Mapam Yamco Lake was shrinking due to higher evaporation and lower precipitation. In addition to glacier meltwater, there are other forms of supply, such as groundwater, wetlands, and permafrost ablation. Abstract Copyright (2014) Elsevier, B.V.
DOI: 10.1016/j.quaint.2014.04.051
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www.hou.usra.edu/meetings/lpsc2015/pdf/1226.pdf
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