Permafrost Monthly Alerts (PMAs)

2017039320 Batir, Joseph F. (Southern Methodist University, Roy M. Huffington Department of Earth Science, Dallas, TX); Hornbach, Matthew J. and Blackwell, David D. Ten years of measurements and modeling of soil temperature changes and their effects on permafrost in northwestern Alaska: Global and Planetary Change, 148, p. 55-71, illus. incl. 1 table, sketch maps, 53 ref., January 2017. Includes appendices.

Multiple studies demonstrate Northwest Alaska and the Alaskan North Slope are warming. Melting permafrost causes surface destabilization and ecological changes. Here, we use thermistors permanently installed in 1996 in a borehole in northwestern Alaska to study past, present, and future ground and subsurface temperature change, and from this, forecast future permafrost degradation in the region. We measure and model Ground Surface Temperature (GST) warming trends for a 10 year period using equilibrium Temperature-Depth (TD) measurements from borehole T96-012, located near the Red Dog Mine in northwestern Alaska-part of the Arctic ecosystem where a continuous permafrost layer exists. Temperature measurements from 1996 to 2006 indicate the subsurface has clearly warmed at depths shallower than 70 m. Seasonal climate effects are visible in the data to a depth of 30 m based on a visible sinusoidal pattern in the TD plots that correlate with season patterns. Using numerical models constrained by thermal conductivity and temperature measurements at the site, we show that steady warming at depths of ~ 30 to 70 m is most likely the direct result of longer term (decadal-scale) surface warming. The analysis indicates the GST in the region is warming at ~ 0.44 ± 0.05 °C/decade, a value consistent with Surface Air Temperature (SAT) warming of ~ 1.0 ± 0.8 °C/decade observed at Red Dog Mine, but with much lower uncertainty. The high annual variability in the SAT signal produces significant uncertainty in SAT trends. The high annual variability is filtered out of the GST signal by the low thermal diffusivity of the subsurface. Comparison of our results to recent permafrost monitoring studies suggests changes in latitude in the polar regions significantly impacts warming rates. North Slope average GST warming is ~ 0.9 ± 0.5 °C/decade, double our observations at RDM, but within error. The RDM warming rate is within the warming variation observed in eastern Alaska, 0.36-0.71 °C/decade, which suggests changes in longitude produce a smaller impact but have warming variability likely related to ecosystem, elevation, microclimates, etc. changes. We also forward model future warming by assuming a 1D diffusive heat flow model and incorporating latent heat effects for permafrost melting. Our analysis indicates ~ 1 to 4 m of loss at the upper permafrost boundary, a ~ 145 ± 100% increase in the active layer thickness by 2055. If warming continues at a constant rate of ~ 0.44 ± 0.05 °C/decade, we estimate the 125 m thick zone of permafrost at this site will completely melt by ~ 2150. Permafrost is expected to melt by ~ 2200, ~ 2110, or ~ 2080, if the rate of warming is altered to 0.25, 0.90, or 2.0 °C/decade, respectively, as an array of different climate models suggest. Since our model assumes no advection of heat (a more efficient heat transport mechanism), and no accelerated warming, our current prediction of complete permafrost loss by 2150 may overestimate the residence time of permafrost in this region of Northwest Alaska.

DOI: 10.1016/j.gloplacha.2016.11.009

2017038690 Zhang Mingyi (Chinese Academy of Sciences, Laboratory of Frozen Soil Engineering, Lanzhou, China); Pei Wansheng; Zhang Xiyin and Lu Jianguo. Lateral thermal disturbance of embankments in the permafrost regions of the Qinghai-Tibet engineering corridor: Natural Hazards, 78(3), p. 2121-2142, illus. incl. 6 tables, 35 ref., September 2015.

Numerous engineering projects have been completed on the Qinghai-Tibet Plateau, and with continued economic growth, additional important engineering projects are being planned. Major transportation construction is largely restricted to the Qinghai-Tibet Engineering Corridor, which is as narrow as a few hundred meters in some places. In this narrow corridor, projects such as the Qinghai-Tibet Railway and the Qinghai-Tibet Highway can influence the stability of the permafrost. We use a numerical model to investigate the individual thermal disturbance caused by the Qinghai-Tibet Railway, the Qinghai-Tibet Highway, and the planned Qinghai-Tibet Expressway. To simulate an upper limit of disturbance under current climate we use the most unfavorable combination of engineering design practices, with unprotected embankments, a traditional ballast embankment for the Qinghai-Tibet Railway, and traditional asphalt pavement embankments for the Qinghai-Tibet Highway and the Qinghai-Tibet Expressway. The lateral thermal disturbance extent of the three projects increases linearly with embankment height. Under the same embankment heights, the lateral extent of thermal disturbance is smallest for the Qinghai-Tibet Railway and is largest for the full Qinghai-Tibet Expressway. The model results provide guidance for minimum distances between the transportation projects to prevent thermal interaction, as a function of embankment height and design. In future research it is important to evaluate the thermal disturbance scopes of other engineering structures, such as tunnels, bridges, and oil pipelines, and to evaluate the thermal interaction and cumulative impact of multiple structures under current and future climate scenarios. Copyright 2015 Springer Science+Business Media Dordrecht

DOI: 10.1007/s11069-015-1823-6

2017033574 Debol'skaya, E. I. (Russian Academy of Sciences, Water Problems Institute, Moscow, Russian Federation). A mathematical model of channel deformations in permafrost zone rivers: Water Resources, 41(5), p. 512-521, illus., 21 ref., September 2014.

A mathematical model is presented, allowing the calculation of channel deformations of permafrost zone rivers caused by thermo-erosional niching under the effect of waves of different origin under the conditions of growing ambient temperature. The model is based on equations of transient fluid motion in two-dimensional formulation, Stefan equation for determining the displacement of water-ice phase transition interface, and mass conservation equations for transported sediments (deformation equations). The model was tested against a particular case of steady flow based on data of a laboratory experiment. Numerical experiments revealed the key factors of the process and allowed the impact of waves with different duration and intensity (spring floods and releases from engineering structures) on river channel to be analyzed. Copyright 2014 Pleiades Publishing, Ltd.

DOI: 10.1134/S0097807814050029

2017038612 Hong Tao (Chinese Academy of Geological Sciences, Institute of Karst Geology, Guilin, China); Liang Sihai; Sun Yu; Zhao Zhenwei; Hao Yupei; Wang Xusheng and Wan Li. Analyzing the factors that impact the heat conductivity coefficient and using them to simulate the depth of permafrost and the active layer in the headwaters of the Yellow River: Bingchuan Dongtu = Journal of Glaciology and Geocryology, 35(4), p. 824-833, (Chinese) (English sum.), illus. incl. 4 tables, sketch map, 31 ref., August 2013.

Analyzing the heat conductivity coefficient within the active layer in permafrost is of scientific value for understanding the response of permafrost to global climate change and its impact on the environment. Dry bulk density, water content and temperature were related to the heat conductivity coefficient of three typical soils in the headwaters of the Yellow River. It was found that dry bulk density and water content are the major factors controlling the heat conductivity coefficient, but the relation between temperature and the heat conductivity coefficient is not obvious. Employing the Stephen function and GIS software, based on measured heat conductivity coefficients, the maximum thawed depths and maximum frozen depths in 2002 were simulated. The simulation shows that the maximum thawed depth at low altitude, such as in the Yellow River and Gyaring and Ngoring Lakes, is greater than that at high altitude, such as Buqingshan Mountain and the Bayan Har Mountains. In contrast, the maximum frozen depth at low altitude is less than that at high altitude. Comparing the maximum thawed depth and the maximum frozen depth, it is found that most permafrost undergoes degradation, except for a small part in the north. The findings of this study may have broad implications for assessing variation in permafrost and the ecological environment due to climate change.

URL: http://bcdt.westgis.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=32 ...

2017038618 Wen Jing (Lanzhou University, College of Earth and Environmental Sciences, Lanzhou, China); Wang Yibo; Gao Zeyong and Liu Guohua. Soil hydrological characteristics of the degrading meadow in permafrost regions of the Beiluhe River basin: Bingchuan Dongtu = Journal of Glaciology and Geocryology, 35(4), p. 929-937, (Chinese) (English sum.), illus. incl. 5 tables, 24 ref., August 2013.

This research was carried out in the Beiluhe River basin on the Tibetan Plateau, which is in the source regions of the Yangtze River, where degrading meadows are severely affected by freezing and thawing. We chose typical areas for experiments and simulation, and studied the soil water characteristics, saturated soil hydraulic conductivity, soil particle size fractionation, soil bulk density, and other soil properties at different depths. The results show that the power function equation proposed by Gardner et al. and van Genuchten has a good simulation function for soil moisture characteristics; there is a critical value of the soil moisture, 0.1 MPa. It is found that the water-retention capacity of the soil at depths of 0-5 cm is the minimum, and reaches a maximum at depths of 20-30 cm. Soil at depths of 0-5 cm has the poorest capacity for providing water supply. Soil at depths of 15-30 cm shows the greatest water supply capacity, and is the optimum soil layer for the growth and development of plant roots. It is also found that saturated soil hydraulic conductivity decreases with depth.

URL: http://bcdt.westgis.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=32 ...

2017032730 Curtis, Aaron (New Mexico Institute of Mining and Technology, Department of Earth and Environmental Science, Socorro, NM) and Kyle, Philip. Methods for mapping and monitoring global glaciovolcanism: Journal of Volcanology and Geothermal Research, 333-334, p. 134-144, illus. incl. 4 tables, sketch maps, 51 ref., March 15, 2017. Includes appendix.

The most deadly (Nevado del Ruiz, 1985) and the most costly (Eyjafjallajokull, 2010) eruptions of the last 100 years were both glaciovolcanic. Considering its great importance to studies of volcanic hazards, global climate, and even astrobiology, the global distribution of glaciovolcanism is insufficiently understood. We present and assess three algorithms for mapping, monitoring, and predicting likely centers of glaciovolcanic activity worldwide. Each algorithm intersects buffer zones representing known Holocene-active volcanic centers with existing datasets of snow, ice, and permafrost. Two detection algorithms, RGGA and PZGA, are simple spatial join operations computed from the Randolph Glacier Inventory and the Permafrost Zonation Index, respectively. The third, MDGA, is an algorithm run on all 15 available years of the MOD10A2 weekly snow cover product from the Terra MODIS satellite radiometer. Shortcomings and advantages of the three methods are discussed, including previously unreported blunders in the MOD10A2 dataset. Comparison of the results leads to an effective approach for integrating the three methods. We show that 20.4% of known Holocene volcanic centers host glaciers or areas of permanent snow. A further 10.9% potentially interact with permafrost. MDGA and PZGA do not rely on any human input, rendering them useful for investigations of change over time. An intermediate step in MDGA involves estimating the snow-covered area at every Holocene volcanic center. These estimations can be updated weekly with no human intervention. To investigate the feasibility of an automatic ice-loss alert system, we consider three examples of glaciovolcanism in the MDGA weekly dataset. We also discuss the potential use of PZGA to model past and future glaciovolcanism based on global circulation model outputs. Combined, the three algorithms provide an automated system for understanding the geographic and temporal patterns of global glaciovolcanism which should be of use for hazard assessment, the search for extreme microbiomes, climate models, and implementation of ice-cover-based volcano monitoring systems.

DOI: 10.1016/j.jvolgeores.2017.01.017

2017039359 Zhao Zhilong (Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, Beijing, China); Liu Fenggui; Zhang Yili; Liu Linshan and Qi Wei. The dynamic response of lakes in the Tuohepingco Basin of the Tibetan Plateau to climate change: Environmental Earth Sciences, 76(3), Article 137, illus. incl. 2 tables, sketch map, 61 ref., February 2017.

The Tibetan Plateau (TP) is particularly sensitive to the influences of climate change. As indicators of climate change, lakes on the TP play a key role in the Earth's climatic system. Lake Yazi (LY), Lake Tuohepingco (LT) and Lake Changtiao (LC) in the Tuohepingco Basin are three inland lakes on the plateau. The extents of LY, LT and LC were obtained using object-based image analysis for remote sensing and 22 images from Landsat satellites (from September to December between 1972 and 2015). Inter-annual changes in the extent of LY, LT and LC were then analyzed. The results show that the total area of the three lakes underwent a change from shrinkage to expansion between 1972 and 2015. In general, there was a trend toward shrinkage during 1972-1999, distinct expansion during 2000-2007 and slight expansion during 2008-2015. Moreover, we found that 14 other lakes have also expanded dramatically since 2000. Lakes at 30°N and 35°N (LY, LT and LC are also located in this region) exhibited the same dramatic period of expansion between 2000 and 2005. In other words, 2000 appears to be a critical transition point for changes in lake size on the TP. Lakes at the same latitudes in the Tibetan Plateau interior may have a similar period of dramatic expansion after 2000. The warming-triggered deglaciation or permafrost degradation, increased precipitation and decreased evapotranspiration may be the influencing factors of lake expansion in the Tuohepingco Basin. Temperature showed relatively higher correlation with lake extent, while precipitation and evaporation were slightly correlated with lake area. Given the importance of wetlands to human society, these are no trivial issues, and we now need accelerated research based on long-term and continuous remote sensing. Copyright 2017 Springer-Verlag Berlin Heidelberg

DOI: 10.1007/s12665-017-6446-7

2017031324 Deline, Philip (Université de Savoie, Laboratoire Environnements, Dynamiques et Territoires de la Montagne, Le Bourget-du-Lac, France); Akcar, Naki; Ivy-Ochs, Susan and Kubik, Peter W. Repeated Holocene rock avalanches onto the Brenva Glacier, Mont Blanc Massif, Italy; a chronology: Quaternary Science Reviews, 126, p. 186-200, illus. incl. 4 tables, sketch map, 76 ref., October 15, 2015.

Infrequent rock avalanches (volume >&eq;1 Mm³) are long-runout processes, especially when travelling onto a glacier, that may threaten populated mountain valleys. Rock avalanches also have strong implications are for relief generation and destruction though time. Both consequences make reconstruction and dating of past events crucial, but dense clusters of events documented in one basin that may improve our knowledge of rock-avalanche frequency and triggering are very rare. Here we propose a chronology of seven of the rock-ice avalanches that affected a steep glacier basin on the southeast side of the Mont Blanc during the late Holocene. A geomorphological study of the runout deposits on the valley floor and the opposite side was combined with the analysis of historical sources and the use of absolute and relative dating methods, especially surface exposure dating with cosmogenic nuclides of 18 granite boulders from two deposits. These rock-ice avalanches are dated AD 1997 and 1920, with a rock volume in the range 2.4-3.6 and 2 ´ 10⁶ m³, respectively; AD 1767, with a slightly shorter runout; AD 1000-1200, with a longer runout; c. AD 500, the runout of which is uncertain; c. 2500 BP, the determination of which is indirect; and c. 3500 years, with the longest runout. There is no distinct relationship between climatic periods and occurrence of these rock avalanches. Even for the two best documented ones, modelling suggests that the 1997 scar was characterized by a permafrost close to 0 °C, whereas in contrast, the 1920 scar was on the contrary located in cold permafrost. Abstract Copyright (2015) Elsevier, B.V.

DOI: 10.1016/j.quascirev.2015.09.004

2017031375 Jiao, Jiu Jimmy (University of Hong Kong, Department of Earth Sciences, Hong Kong, China); Zhang Xiaotao; Liu Yi and Kuang Xingxing. Increased water storage in the Qaidam Basin, the north Tibet Plateau from GRACE gravity data: PLoS One, 2015(e0141442), illus. incl. 2 tables, sketch maps, 47 ref., October 27, 2015.

Groundwater plays a key role in maintaining the ecology and environment in the hyperarid Qaidam Basin (QB). Indirect evidence and data from sparse observation wells suggest that groundwater in the QB is increasing but there has been no regional assessment of the groundwater conditions in the entire basin because of its remoteness and the severity of the arid environment. Here we report changes in the spatial and temporal distribution of terrestrial water storage (TWS) in the northern Tibetan Plateau (NTP) using Gravity Recovery and Climate Experiment (GRACE) data. Our study confirms long-term (2003-2012) TWS increases in the NTP. Between 2003 and 2012 the TWS increased by 88.4 and 20.6 km³ in the NTP and the QB, respectively, which is 225% and 52% of the capacity of the Three Gorges Reservoir, respectively. Soil and water changes from the Global Land Data Assimilation System (GLDAS) were also used to identify groundwater storage in the TWS and to demonstrate a long-term increase in groundwater storage in the QB. We demonstrate that increases in groundwater, not lake water, are dominant in the QB, as observed by groundwater levels. Our study suggests that the TWS increase was likely caused by a regional increase in precipitation and a decrease in evaporation. Degradation of the permafrost increases the thickness of the active layers providing increased storage for infiltrated precipitation and snow and ice melt water, which may also contribute to the increased TWS. The huge increase of water storage in the NTP will have profound effects, not only on local ecology and environment, but also on global water storage and sea level changes.

DOI: 10.1371/journal.pone.0141442

2017033578 Karavaeva, N. A. (Russian Academy of Sciences, Institute of Geography, Moscow, Russian Federation) and Sokolova, T. A. Cryometamorphic gleyzems in the taiga of western Siberia; chemical and mineralogical properties, ecology, and genesis: Eurasian Soil Science, 47(8), p. 741-751, 36 ref., August 2014. Based on Publisher-supplied data.

Earlier studies showed considerable differences in the properties of automorphic loamy soils developing under middle-taiga vegetation in Western Siberia and on the Russian Plain. It was found that the soils without clear features of textural differentiation are common in Western Siberia. In particular, they are represented by cryometamorphic gleyzems. In this study, we analyze the properties of a cryometamorphic gleyzem in the Vakh area (the Khanty-Mansi Autonomous Okrug). The distribution pattern of clay minerals in the soil profile is analyzed in relation to the specific features of the soil hydrothermic regime. In the upper mineral horizons, the clay fraction is enriched in minerals of the group of soil chlorites and somewhat depleted of labile phyllosilicates. In the cryometamorphic horizon and in the underlying permafrost, the degree of crystallization of the clay minerals somewhat decreases. An even distribution pattern of aluminum oxide in the soil profile is explained by the increased content of Al in the clay fraction from the upper horizons combined with the loss of Al from the coarse fractions (as judged from data on the bulk elemental composition of clay-free samples). These features can be explained by the specificity of the hydrothermic regime of the cryometamorphic gleyzems with late thawing of the soil profile and frequent phase transitions of soil water in the upper humus and middle-profile cryometamorphic horizons. Copyright 2014 Pleiades Publishing, Ltd.

DOI: 10.1134/S1064229314080055

2017038364 Kachinskii, V. L. (Moscow State University, Geographical Faculty, Moscow, Russian Federation); Zavgorodnyaya, Yu. A. and Gennadiev, A. N. Hydrocarbon contamination of arctic tundra soils of the Bol'shoi Lyakhovskii Island (the Novosibirskie Islands): Eurasian Soil Science, 47(2), p. 57-69, 39 ref., February 2014. Based on Publisher-supplied data.

Data on the distribution of the components of oil products that have accumulated in the arctic tundra soils of the Bol'shoi Lyakhovskii Island (the Novosibirskie Islands) under the impact of technogenic loads are analyzed. The examined soils differ in the vertical and lateral distribution patterns of the methanenaphthenic and naphthenic hydrocarbons and in the degree of their transformation. This is determined by the position of particular soils in the catenas and by the sorption of particular hydrocarbon compounds in the soils. The portion of light molecular-weight hydrocarbons in the upper horizons decreases by two-ten times in comparison with the deeper soil layers. In the lateral direction, the twofold difference in the contents of the methane-naphthenic and naphthenic hydrocarbons in the upper horizons is seen. The degree of transformation of the hydrocarbons under the impact of microbiological processes depends on the aeration conditions, the depth of permafrost table, the composition of oil products, and the soil organic matter content. Copyright 2014 Pleiades Publishing, Ltd.

DOI: 10.1134/S1064229314020070

2017032549 Kovda, Irina (Russian Academy of Sciences, Institute of Geography, Moscow, Russian Federation); Goryachkin, Sergey; Lebedeva, Marina; Chizhikova, Natalia; Kulikov, Anatoly and Badmaev, Nimazhap. Vertic soils and Vertisols in cryogenic environments of southern Siberia, Russia: Geoderma, 288, p. 184-195, illus. incl. 7 tables, sketch map, 69 ref., February 15, 2017.

Vertisols and vertic soils are known in a wide range of bioclimatic environments. The aim of this research was to identify possible vertic features in ultra-continental climate with gelic soil temperature regime with MAAT < 1 °C. Detailed morphological investigation supported by micromorphological and physical attributes identified vertic features both at the order and subgroup levels in Buryatia (Trans-Baikal region), where soils are formed under MAAT - 4.2 °C, and are underlain by permafrost. Vertisol was found in the shoulder position, while the soils of the summit and the backslope position were classified as vertic intergrades of Phaeozem. Vertisol has cracks on the surface, slickensides and wedge-shaped aggregates within the profile, 47-55% of clay, extremely high smectite contents (up to 98% of clay fraction). Vertic Phaeozems on the summit and backslope positions have similar morphological attributes but at the initial stage of formation, and without the formation of vertic horizon. Both Vertisol and Vertic Phaeozems have vertic features at microlevel such as a variety of striated b-fabrics, an open porphyric c/f-related distribution, planar voids, a blocky microstructure, wedge-shaped microaggregates. These soils have been formed under the joint impact of deep winter freezing, permafrost formation, and shrink-swell processes, and show the combination of primary cryogenic features and cryogenic features transformed by the shrink-swell and shearing processes.We found that Vertisols can form not only in cold environments, but also in ultra-continental cold environments with permafrost and negative mean annual air temperatures. However, their areas in Buryatia are limited in size to the warmest and driest positions in the landscape, namely south facing slopes. The discovery of Vertisols in ultra-continental climates will be a challenge for current soil classification systems, like Soil Taxonomy, which will need a provisional taxonomic category to accommodate such soils under gelic temperature regimes. We propose to introduce Gelert suborder and Vertic subgroup to Haplogeloll great group.

DOI: 10.1016/j.geoderma.2016.11.008

2017039222 Salama, Walid (CSIRO, Mineral Resources, Perth, West. Aust., Australia) and Anand, Ravi R. Reconstructing the pre-Quaternary landscape in Agnew-Lawlers area, Western Australia with emphasis on the Permo-Carboniferous glaciation and post-glacial weathering: International Journal of Earth Sciences = Geologische Rundschau, 106(1), p. 311-339, illus. incl. 3 plates, 1 table, geol. sketch maps, 115 ref., January 2017.

The pre-Quaternary stratigraphic section in Agnew-Lawlers area consists of Permo-Carboniferous glacial sediments, unconformably overlain by Tertiary clastics of palaeochannel sequence and Quaternary alluvial and colluvial sediments. The unique Permo-Carboniferous glacial sedimentary succession in the Yilgarn Craton has not been studied in detail in terms of vertical chemostratigraphic variations, basin and landscape evolution, diagenesis and post-Permian weathering overprints. In Agnew-Lawlers district, continental facies of glacial diamictites, glaciofluvial sandstones and glaciolacustrine rhythmites vary in thickness from 28 m to 181 m and is preserved beneath Cenozoic sediments as relict landforms in highly irregular, asymmetrical and poorly drained basins. The Permo-Carboniferous sediments were mechanically weathered and eroded by glaciers from the surrounding Archaean basement palaeohighs under a cold arid climate. Textural relationships of diamictites indicate that they were derived from proximal and distal source rocks. The denuded palaeotopography of the basement palaeohighs (source rocks) and Permo-Carboniferous sediments were subjected simultaneously to an intensive, post-Permian chemical weathering. The exposed basement rocks were deeply weathered into residual saprolite, whereas the Permo-Carboniferous sediments were differentiated into three chemostratigraphic units. The diamictite and rhythmite of the lower unit are unweathered and preserves the signature of the glacial/interglacial weathering. Mineralogical and geochemical changes dominated in this unit are related mainly to diagenesis at shallow depth (eogenesis) with no significant compaction. The formation of a paragenetic diagenetic sequence of chlorite, ferroan dolomite and pyrite indicates diagenesis has occurred under reducing and alkaline conditions below the permafrost and modern water table. Mineralogical and geochemical changes dominated in the middle unit are linked mainly to eogenetic redox reactions. The formation of smectite and ferruginous cements in this unit is attributed to weathering of ferromagnesian and opaque heavy minerals under oxic and slightly alkaline conditions. Mineralogical and geochemical changes dominated in the upper unit is related mainly to Post-Permian chemical weathering, where almost all rock-forming minerals are altered to kaolinite and alkali and alkaline earth elements are leached forming bleached white saprolitic diamictites. A change in clay minerals from kaolinite in the weathered Permo-Carboniferous succession to smectite in the overlying Cenozoic succession demarcates the unconformity and probably reflects a change to an arid climatic condition. Chemically, the Cenozoic succession shows a sharp increase in Ti/Al and La/Ce ratios and a decrease in Ce anomaly that remain constant in the Permo-Carboniferous section. These mineralogical and chemical variations through the Phanerozoic stratigraphic section can be used to follow the landscape and climatic evolution since the late Palaeozoic glaciation. Copyright 2017 Springer-Verlag Berlin Heidelberg and 2016 Her Majesty the Queen in Right of Australia

DOI: 10.1007/s00531-016-1320-5

2017031326 Finkenbinder, M. S. (University of Pittsburgh, Department of Geology and Planetary Science, Pittsburgh, PA); Abbott, Mark B.; Finney, Bruce P.; Stoner, J. S. and Dorfman, J. M. A multi-proxy reconstruction of environmental change spanning the last 37,000 years from Burial Lake, Arctic Alaska: Quaternary Science Reviews, 126, p. 227-241, illus. incl. 2 tables, sketch map, 81 ref., October 15, 2015.

Sediment cores from Burial Lake located in the western Brooks Range in Arctic Alaska record paleoenvironmental changes that span the last 37,000 calendar years before present (cal yr BP). We identified four distinct lithologic subunits based on physical properties (dry bulk density, magnetic susceptibility), sediment composition, and geochemical proxies (organic matter, biogenic silica, C/N, organic matter d¹³C and d¹⁵N, and elemental data from scanning X-ray fluorescence). The multi-proxy approach and relatively high temporal resolution (at multi-decadal to centennial time scales) of our proxy analysis, compared with previous studies of intermediate water depth cores from Burial Lake, provide new insights into the paleoenvironmental history of the region spanning the period prior to the Last Glacial Maximum. Relatively high lake-levels and gradually decreasing in-lake and terrestrial productivity occur during the mid-Wisconsin interstadial from 37,200 to 29,600 cal yr BP. The subsequent period is defined by falling and lower lake-levels with decreasing effective-moisture, windier conditions, and sustained low aquatic productivity throughout the LGM between 29,600 and 19,600 cal yr BP. The last deglaciation that commenced by 19,600 cal yr BP is characterized by gradual changes in several sediment physical and geochemical proxies, including increasing C/N ratios and terrestrial productivity, decreasing magnetic susceptibility and clastic sediment flux, along with rising and relatively higher lake-levels. A decrease in aeolian activity after 16,500 cal yr BP is inferred from the appearance of fine (very fine sandy silt) sediment, compared to coarse sediments through the LGM and last deglaciation. The highest levels of terrestrial inputs along with increasing and variable aquatic productivity occur during the Lateglacial to early Holocene interval between 16,500 and 8800 cal yr BP. The absence of multi-proxy evidence for a strong climatic reversal during the Younger Dryas from Burial Lake sediments contrasts with some paleorecords showing cooler temperatures and/or dry conditions in northern Alaska at this time. Peak levels of sediment organic content and terrestrial productivity at Burial Lake between 10,500 and 9900 cal yr BP coincide with the early Holocene summer insolation maxima, which likely represents summertime warming and an enhanced flux of watershed derived organic matter from permafrost degradation. The remainder of the Holocene (since 8800 cal yr BP) at Burial Lake is characterized by relatively high and stable lake levels, landscape stabilization, and relatively high and variable levels of aquatic productivity. Abstract Copyright (2015) Elsevier, B.V.

DOI: 10.1016/j.quascirev.2015.08.031

2017033700 Tylmann, Karol (Uniwersytet Mikolaja Kopernika, Katedra Geologii i Hydrogeologii, Torun, Poland); Wysota, Wojciech and Piotrowski, Jan A. Przetrwale moreny czolowe na NW sklonie Garbu Lubawskiego; struktura i mechanizmy formowania [Palimpsest terminal moraines in NW part of Lubawa Upland; structure and mechanisms of formation]: LA. Landform Analysis, 25, p. 143-157 (English sum.), illus. incl. block diags., strat. cols., 1 table, sketch map, 51 ref., 2014.

This article presents the results of lithofacies and structural studies of deposits in the palimpsest terminal moraines on the NW slope of Lubawa Upland. The results document a complex origin of these hills and some distinct features suggesting their palimpsest nature. We propose genetic models highlighting the main stages of their formation as well as the mechanisms of their preservation in the subglacial system. The inner structure of the hills suggests a crucial role of permafrost in preservation protecting the hills from erosion under the last Scandinavian Ice Sheet.

DOI: 10.12657/landfana.025.013

2017033899 Zhang, Bin (Michael Baker International, Moon Township, PA); Han, Chanjuan and Yu, Xiong Bill. A non-destructive method to measure the thermal properties of frozen soils during phase transition: Journal of Rock Mechanics and Geotechnical Engineering, 7(2), p. 155-162, illus., 45 ref., April 2015.

Frozen soils cover about 40% of the land surface on the earth and are responsible for the global energy balances affecting the climate. Measurement of the thermal properties of frozen soils during phase transition is important for analyzing the thermal transport process. Due to the involvement of phase transition, the thermal properties of frozen soils are rather complex. This paper introduces the uses of a multifunctional instrument that integrates time domain reflectometry (TDR) sensor and thermal pulse technology (TPT) to measure the thermal properties of soil during phase transition. With this method, the extent of phase transition (freezing/thawing) was measured with the TDR module; and the corresponding thermal properties were measured with the TPT module. Therefore, the variation of thermal properties with the extent of freezing/thawing can be obtained. Wet soils were used to demonstrate the performance of this measurement method. The performance of individual modules was first validated with designed experiments. The new sensor was then used to monitor the properties of soils during freezing-thawing process, from which the freezing/thawing degree and thermal properties were simultaneously measured. The results are consistent with documented trends of thermal properties variations.

DOI: 10.1016/j.jrmge.2015.03.005

2017038659 Kang Yongshui (Chinese Academy of Sciences, Institute of Rock and Soil Mechanics, State Key Laboratory of Geomechanics and Geotechnical Engineering, Wuhan, China); Liu Quansheng; Liu Xiaoyan and Huang Shibing. Theoretical and numerical studies of crack initiation and propagation in rock masses under freezing pressure and far-field stress: Journal of Rock Mechanics and Geotechnical Engineering, 6(5), p. 466-476, illus. incl. 1 table, 18 ref., October 2014.

Water-bearing rocks exposed to freezing temperature can be subjected to freeze-thaw cycles leading to crack initiation and propagation, which are the main causes of frost damage to rocks. Based on the Griffith theory of brittle fracture mechanics, the crack initiation criterion, propagation direction, and crack length under freezing pressure and far-field stress are analyzed. Furthermore, a calculation method is proposed for the stress intensity factor (SIF) of the crack tip under non-uniformly distributed freezing pressure. The formulae for the crack/fracture propagation direction and length of the wing crack under freezing pressure are obtained, and the mechanism for coalescence of adjacent cracks is investigated. In addition, the necessary conditions for different coalescence modes of cracks are studied. Using the topology theory, a new algorithm for frost crack propagation is proposed, which has the capability to define the crack growth path and identify and update the cracked elements. A model that incorporates multiple cracks is built by ANSYS and then imported into FLAC^3D. The SIFs are then calculated using a FISH procedure, and the growth path of the freezing cracks after several calculation steps is demonstrated using the new algorithm. The proposed method can be applied to rocks containing fillings such as detritus and slurry.

DOI: 10.1016/j.jrmge.2014.05.004

2017033490 Schneider, D. (Universität Zürich, Geographie, Zurich, Switzerland); Huggel, Christian; Cochachin, A.; Guillén, S. and García, J. Mapping hazards from glacier lake outburst floods based on modelling of process cascades at Lake 513, Carhuaz, Peru: Advances in Geosciences, 35, p. 145-155, illus. incl. 1 table, geol. sketch maps, 39 ref., 2014.

Recent warming has had enormous impacts on glaciers and high-mountain environments. Hazards have changed or new ones have emerged, including those from glacier lakes that form as glaciers retreat. The Andes of Peru have repeatedly been severely impacted by glacier lake outburst floods in the past. An important recent event occurred in the Cordillera Blanca in 2010 when an ice avalanche impacted a glacier lake and triggered an outburst flood that affected the downstream communities and city of Carhuaz. In this study we evaluate how such complex cascades of mass movement processes can be simulated coupling different physically-based numerical models. We furthermore develop an approach that allows us to elaborate corresponding hazard maps according to existing guidelines for debris flows and based on modelling results and field work.

URL: http://www.adv-geosci.net/35/145/2014/adgeo-35-145-2014.pdf

2017033476 Crenshaw, Brad (Ground Engineering Contractors). Mitigating inflow due to both primary and secondary permeability in mining: in A focus on mining; PLUS-2013 annual meeting preview, AEG News, 56(2), p. 31-34, illus., June 2013.

2017037316 Neckel, Niklas (Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany); Loibl, David and Rankl, Melanie. Recent slowdown and thinning of debris-covered glaciers in southeastern Tibet: Earth and Planetary Science Letters, 464, p. 95-102, illus. incl. 2 tables, sketch maps, 58 ref., April 15, 2017. Includes appendix.

Recent large-scale remote sensing studies have shown that glacier mass loss in south-eastern Tibet, specifically in the eastern Nyainqentanglha Range exceeds the average in High Asia. However, detailed studies at individual glaciers are scarce and the drivers behind the observed changes are poorly constrained to date. Employing feature tracking techniques on TerraSAR-X data for the periods 2008/2009, 2012/2013 and 2013/2014 we found measurable surface velocities through to the glacier terminus positions of five debris-covered glacier tongues. This is contrary to debris-covered glaciers in other parts of High Asia, where stagnant glacier tongues are common. Our feature tracking results for the 2013/2014 period suggest an average deceleration of 51% when compared with published Landsat velocities for the period 1999/2003. Further, we estimated surface elevation changes for the five glaciers from recently released one arc second resolution elevation data obtained during the Shuttle Radar Topography Mission in 2000 and an interferometrical derived TanDEM-X elevation model for the year 2014. With an average rate of -0.83 ± 0.57 m a^-1 we confirm strong surface lowering in the region, despite the widely discussed insulation effect of debris cover. Beside the influence of thermokarst processes and delayed response times of debris-covered glaciers, we highlight that abundant monsoonal summer rainfall might contribute significantly to the pronounced negative mass balances in the study region.

DOI: 10.1016/j.epsl.2017.02.008

2017032692 Mundy, Erin (McGill University, Department of Civil Engineering, Montreal, QC, Canada); Gleeson, Tom; Roberts, Mark; Baraer, Michel and McKenzie, Jeffrey M. Thermal imagery of groundwater seeps; possibilities and limitations: Ground Water, 55(2), p. 160-170, illus., 32 ref., March 2017.

Quantifying groundwater flow at seepage faces is crucial because seepage faces influence the hydroecology and water budgets of watersheds, lakes, rivers and oceans, and because measuring groundwater fluxes directly in aquifers is extremely difficult. Seepage faces provide a direct and measurable groundwater flux but there is no existing method to quantitatively image groundwater processes at this boundary. Our objective is to determine the possibilities and limitations of thermal imagery in quantifying groundwater discharge from discrete seeps. We developed a conceptual model of temperature below discrete seeps, observed 20 seeps spectacularly exposed in three dimensions at an unused limestone quarry and conducted field experiments to examine the role of diurnal changes and rock face heterogeneity on thermal imagery. The conceptual model suggests that convective air-water heat exchange driven by temperature differences is the dominant heat transfer mechanism. Thermal imagery is effective at locating and characterizing the flux of groundwater seeps. Areas of active groundwater flow and ice growth can be identified from thermal images in the winter, and seepage rates can be differentiated in the summer. However, the application of thermal imagery is limited by diverse factors including technical issues of image acquisition, diurnal changes in radiation and temperature, and rock face heterogeneity. Groundwater discharge rates could not be directly quantified from thermal imagery using our observations but our conceptual model and experiments suggest that thermal imagery could quantify groundwater discharge when there are large temperature differences, simple cliff faces, non-freezing conditions, and no solar radiation. Abstract Copyright (2016), , National Ground Water Association.

DOI: 10.1111/gwat.12451

2017034843 Freire-Lista, David M. (Universidad Complutense de Madrid, Instituto de Geociencias, Madrid, Spain). Deterioro de granito utilizado en construcción tradicional [Deterioration of granite used in traditional construction]: Naturaleza Aragonesa, 33, p. 27-31, illus., 6 ref., 2016.

2017038684 Guo Bing (Chinese Academy of Science, Institute of Remote Sensing and Digital Earth, Beijing, China); Zhou Yi; Zhu Jinfeng; Liu Wenliang; Wang Futao; Wang Litao and Jiang Lin. An estimation method of soil freeze-thaw erosion in the Qinghai-Tibet Plateau: Natural Hazards, 78(3), p. 1843-1857, illus. incl. 4 tables, sketch map, 46 ref., September 2015.

Limited by natural and scientific factors, freeze-thaw (FT) erosion, as a typical erosion process along with wind and water erosion, has not been given enough attention. In this paper, we introduce microwave remote sensing techniques to establish an estimation model of FT erosion. The model includes seven factors: the annual FT cycle days, the average diurnal FT phase-changed water content, average annual precipitation, topographic relief, aspect, annual temperature range and vegetation coverage. The results show that on the whole Qinghai-Tibet Plateau scale, the average intensity of FT erosion belongs to the category of moderate erosion. The spatial extent of the FT erosion region is 163.96 (10⁴) km², accounting for 63.46% of the study region. Exhibiting spatial heterogeneity, the distribution of the FT erosion shows an upward trend where the erosion intensity increases from slight erosion in the northwestern region to severe erosion in the southeastern part of the study region. Because of the vast extent of the Qinghai-Tibet Plateau, the dominant impact factors for the FT cycle differ over the area. The mid-west plateau is mainly influenced by the annual FT cycle days, average diurnal phase-changed water content and temperature. The southern and southeastern zones are influenced by precipitation, topographic relief and aspect. During the study period, regions which dominated by alpine shrubs were the most severely affected by FT erosion. The results show significance for the understanding of the mechanism and occurrence of FT erosion and therefore provide a scientific basis for the prevention and treatment of FT erosion. Copyright 2015 Springer Science+Business Media Dordrecht

DOI: 10.1007/s11069-015-1808-5

2017038617 Geng Ke (Gansu Changda Highway Company, Lanzhou, China). Impacts of the freeze-thaw cycle on frost heaving forces on tunnel structures in cold regions: Bingchuan Dongtu = Journal of Glaciology and Geocryology, 35(4), p. 913-919, (Chinese) (English sum.), illus. incl. 2 tables, 9 ref., August 2013.

In order to understand the effects of the freeze-thaw cycle and frost heaving forces on tunnel structures in cold regions, taking the highway tunnel in the cold region of Inner Mongolia (Alatan Highway Tunnel) as an example, frost heaving forces were calculated by the method of elasticity mechanics in this paper. Thermal-stress field coupling analysis on the tunnel section was conducted with the finite element simulation software ANSYS. The frost heaving pressures on the tunnel section after freeze-thaw cycles of 50 years are worked out. The results of the elastic mechanics method and in-situ testing are compared and analyzed. It is found that the theoretical and the numerical simulated results are relatively similar. The change in loading conditions on the structures during tunnel operation can be understood by comparing the theoretical and numerical simulated results of frost heaving pressures on the tunnel. Thus the degree of safety and reliability of the tunnel structures can be determined.

URL: http://bcdt.westgis.ac.cn/EN/article/downloadArticleFile.do?attachType=PDF&id=32 ...

Back to the Top

2017037221 Cassidy, Alison Elizabeth. The impacts of High Arctic permafrost disturbances on vegetation and carbon flux dynamics: 143 p., illus. incl. 16 tables, sketch maps, 152 ref., Doctoral, 2016, University of British Columbia, Vancouver, BC, Canada. Includes appendices.

Changing climate and disturbance regimes can have widespread ecosystem impacts, especially in the Arctic. Vegetation recovery and carbon flux dynamics were examined to determine the impacts of thermokarst disturbance on patterns and processes in High Arctic tundra ecosystems. Ecosystem responses to two forms of permafrost disturbance, active layer detachment slides and retrogressive thaw slumps, were studied on the Fosheim Peninsula, Ellesmere Island, Canada during the 2012, 2013, and 2014 growing seasons. The impacts of disturbance on vegetation and recovery were determined by sampling active retrogressive thaw slumps and recovered active layer detachment slides that were investigated nearly 20 years ago. Comparison of historic and modern data indicates distinct vegetation communities exist in differently aged disturbances with unique vascular plant species defining various zones and ages of disturbance. Differences were also found in site characteristics (including soil moisture, temperature, active layer depth, and soil nutrient concentrations) indicating the impacts of permafrost disturbance on the landscape. In addition, four active layer detachment slides measured in 1994 had transitioned to active retrogressive thaw slumps, which may be a response to the progressively warming climate. Carbon dioxide fluxes between the surface and the atmosphere were measured using a static chamber system and the eddy covariance technique at three sites on the Fosheim Peninsula. Over the studied growing seasons, disturbed landscapes sequestered significantly less carbon than their surrounding undisturbed tundra. In some sites, this resulted in the shift of the system from a net sink of CO₂ to a net source. A dual eddy covariance sampling approach was found to be preferable over a single tower setup with separation of fluxes based on wind partitioning as disturbed and undisturbed fluxes were simultaneously measured throughout the growing season using this method. Overall, active layer detachments and retrogressive thaw slumps alter vegetation and carbon flux dynamics, and these changes may persist over many years. With predicted increases in the frequency and magnitude of these permafrost disturbances, impacts on tundra ecosystems will be evident at the landscape scale.

DOI: 10.14288/1.0315351

Back to the Top

2017036834 Evans, Sarah G. (University of Colorado at Boulder, Department of Geological Sciences, Boulder, CO) and Ge, Shemin. Contrasting hydrogeologic responses to climate warming in permafrost and seasonally frozen ground [abstr.]: in Geological Society of America, 2016 annual meeting & exposition, Abstracts with Programs - Geological Society of America, 48(7), Abstract no. 188-10, 2016. Meeting: Geological Society of America, 2016 annual meeting & exposition, Sept. 25-28, 2016, Denver, CO.

Permafrost and seasonally frozen ground underlay approximately half of the Northern Hemisphere exposed land surface. Climate warming is expected to reduce the areal extent of both permafrost and seasonally frozen ground, altering groundwater discharge to streams. While the effects of permafrost degradation on groundwater discharge have been analyzed, quantification of how groundwater discharge in degrading permafrost differs from that in seasonally frozen ground is lacking. This study simulates coupled groundwater flow and heat transport under freeze-thaw conditions for hillslopes underlain by permafrost and seasonally frozen ground and compares groundwater discharge outputs under both non-warming and IPCC-projected warming scenarios over decadal scales. Model results demonstrate that, without warming, seasonally frozen ground hillslopes generally transmit more groundwater flow and have higher magnitudes of groundwater discharge than hillslopes with permafrost. For the parameter scenario considered in this modeling study, there is a maximum of 87% more groundwater discharge in catchments with seasonally frozen ground than with permafrost. With IPCC-projected warming trends, over the coming decades there will be increased groundwater discharge for regions with both permafrost and seasonally frozen ground. Permafrost hillslopes will likely experience an order of magnitude greater relative change in groundwater discharge than hillslopes underlain by seasonally frozen ground despite transmitting a smaller volume of groundwater. In this study, groundwater discharge increased up to 190% in seasonally frozen ground versus up to 1340% in permafrost. These findings indicate that water resource planning in cold regions should prioritize research in permafrost terrains rather than regions with seasonally frozen ground, as areas with permafrost will likely see the largest changes in groundwater contribution to streamflow and consequently, aquatic ecosystems.

2017036632 Correia, A. (University of Evora, Institute of Earth Sciences and Department of Physics, Evora, Portugal); Marc, O. and Ruiz-Fernandez, J. Study of frozen ground conditions in Byers Peninsula of Livingston Island (Maritime Antarctica) based on electrical and geomorphological data [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 4899, illus., 2 ref., 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

Permafrost conditions in the South Shetland Islands (Maritime Antarctica) appear to be marginal to discontinuous, until ca. 20 - 40 m a.s.l., becoming continuous at higher altitudes. However, the presence of permafrost in certain areas of the archipelago is not well understood. That is the case in Byers Peninsula in Livingston Island, the largest ice-free area in the South Shetland Islands. Some studies have shown that in Byers Peninsula permafrost conditions exist in the central plateau at altitudes above 45 m a.s.l., with an active layer thickness of 0.9 - 1.5 m. Geoelectrical methods are an effective method to detect permafrost distribution and permafrost conditions in polar environments. With the purpose of better understanding the existence (or absence) of permanent frozen conditions in Byers Peninsula, a geophysical survey using an electrical resistivity tomography methodology was conducted in late January 2015. The snowy conditions during the cold season in 2014 in Byers Peninsula imposed a late snow melt in 2015, which must be taken into account when interpreting the data related to frozen conditions inferred from the geoelectrical survey. In the same direction three overlapping electrical resistivity tomographies of 78 m each were done along a profile which ran from the coast to the highest marine terraces. For each tomography 40 electrodes were used in a Wenner configuration; adjacent electrodes were 2 m apart. The three electrical resistivity tomographies were combined in an electrical resistivity model which represents the distribution of the electrical resistivity of the ground to depths of about 13 m along 158 m. The software RES2DINV [1][2] was used for inverting the apparent electrical resistivity values into a two-dimensional model of electrical resistivity of the ground (Fig. 1). Several patches of high electrical resistivity are found along the two-dimensional geoelectrical model, which are interpreted as sporadic permafrost. On average, electrical resistivities tend to increase inland. As observed in other polar maritime environments, electrical resistivity values as low as 1000 Wm may be indicative of the presence of permanent frozen conditions in the area. This may suggest the lower limits of sporadic permafrost in the Byers Peninsula, significantly lower than in other ice-free environments in the South Shetland Islands.

URL: http://www.americangeosciences.org/sites/default/files/igc/4899.pdf

2017036587 Li, S. L. (Jilin University, College of Construction Engineering, Changchun, China); Sun, Y. H.; Guo, W. and Jia, R. A further evaluation of mud cooling technology for gas hydrate exploration [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 4536, 2 ref., 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

Mud cooling is a key technology applied in gas hydrate drilling operation to keep the hydrate-bearing sediments below hydrate equilibrium temperature. GHMCS [1] (Gas Hydrate Mud Cooling System), which is a set of special equipment to cool mud, has been designed, constructed and operated in Qinghai-Tibet Plateau and Mohe Basin in China for the exploration of gas hydrate. The gas hydrate bearing cores were obtained with its application in permafrost regions in China and then a steam mining system [2] for natural gas hydrates (SMSGH) was used for the exploitation of natural gas hydrates in the regions. Field test showed the temperature of the mud in the well could be kept lower than that of the hydrate equilibrium while drilling. Our further study shows that the hydrate dissociation in wellbore can also be induced by gas diffusion from pore water to drilling fluid even if the temperature (and the pressure if necessary) of the drilling fluid is well controlled to keep the conditions of hydrate-bearing sediments along the hydrate equilibrium boundary. The dissociation of gas hydrate was modelled based on Fick's first law. It was found that the dissociation rate was mainly dependent on the temperature of the sediments. The locations of dissociation front of CH₄ hydrate in well wall were calculated as a function of time. It was found that hydrate dissociation induced by gas diffusion does not pose a significant wellbore stability risk in a cold drilling through hydrate-bearing sediments. Temperature-controlled technologies like GHMCS can work well in keeping wellbore stable during drilling through hydrate-bearing sediments.

URL: http://www.americangeosciences.org/sites/default/files/igc/4536.pdf

2017039686 Jacobs, Nicole (University of Alaska Fairbanks, Geophysical Institute and Department of Chemistry and Biochemistry, Fairbanks, AK); Simpson, William R.; Strong, Kimberly; Conway, Stephanie A.; Kasai, Yasuko; Dubey, Manvendra Krichna; Parker, Harrison Alexander; Hase, Frank; Blumenstock, Thomas and Tu, Qiansi. An investigation of regional tropospheric methane in central interior Alaska using direct-sun FTIR [abstr.]: in AGU 2016 fall meeting, American Geophysical Union Fall Meeting, 2016, Abstract A41F-0101, December 2016. Meeting: American Geophysical Union 2016 fall meeting, Dec. 12-16, 2016, San Francisco, CA.

Observations suggest that a warming climate is causing permafrost degradation in the sub-Arctic to increase and the boundaries of the Boreal Forest to advance Northward. Many low-lying (often wetland) areas that were once frozen are thawing, changing soil processes, which have the potential to alter carbon gas exchange. Possible changes in carbon emissions in subarctic ecosystems, such as those found in central interior Alaska, warrant an investigation of atmospheric methane (CH4) on a regional scale. In a joint US-Japanese project, ground-based direct-sun Fourier Transform Infrared (FTIR) spectra were collected at Poker Flat Research Range, Alaska (65.12°N, 147.43°W) from 2000 to 2010 using a Bruker IFS120HR spectrometer. From these spectra, vertical profiles of CH4 volume mixing ratio (VMR), as a function of altitude, were estimated with SFIT4 fitting software. A method for calculating VMRs of tropospheric CH4 proposed by Washenfelder et al. (2003, DOI: 10.1029/2003gl017969) was explored and compared to profile estimates for layers with the lowest altitude. This method uses HF total column measurements as a proxy for CH4 oxidation in the stratosphere to correct for stratospheric methane loss. Comparative timeseries were constructed relating CH4 VMR estimated for the surface layer of SFIT4 profiles, tropospheric CH4 VMR calculated using HF total columns, and in situ data from the NOAA site in Barrow, Alaska. In this presentation, we compare the various methods for tropospheric methane measurements and present a timeseries of methane over the ten-year period. The observations can be used in the future to constrain regional methane budgets in the sub-Arctic/Boreal Forest region. Similar direct-sun FTIR observations with a pair of Bruker EM27/Sun mobile spectrometers are being carried out in August and September 2016, and preliminary results from this campaign will also be presented.

2017036869 Krivovichev, Sergey V. (Saint Petersburg State University, Institute of Earth Sciences, Saint Petersburg, Russian Federation); Huskic, Igor; Pekov, Igor V. and Friscic, Tomislav. Minerals with metal-organic framework structures [abstr.]: in Geological Society of America, 2016 annual meeting & exposition, Abstracts with Programs - Geological Society of America, 48(7), Abstract no. 191-4, 2016. Meeting: Geological Society of America, 2016 annual meeting & exposition, Sept. 25-28, 2016, Denver, CO.

Coevolution of the geosphere and biosphere in the history of the Earth results in the appearance of a number of minerals that combine organic and inorganic building blocks, thus representing links between natural organic and inorganic structural chemistries. Such materials are of current interest in material science and attract considerable attention due to their interesting physical and chemical processes. In particular, metal-organic frameworks (MOFs) are an increasingly important family of advanced materials based on open, nanometer-scale metal-organic architectures, whose design and synthesis are based on the directed assembly of carefully designed subunits. It has always been thought that MOFs are typically artificial materials, but recently we have been able to demonstrate that coordination-driven self-assembly used to create advanced materials in the laboratory can also play a role in geological processes [I. Huskic et al. Science Advances, in press]. Stepanovite, (NaMgFe(C₂O₄)₃·8-9H₂O), and zhemchuzhnikovite, (NaMg(Fe_0.4Al_0.6)(C₂O₄)₃·8-9H₂O), are two minerals first discovered near the estuary of Lena river (Sakha-Yakutia, Siberia, Russia) in 1964. Both minerals are water-soluble and were found in drillcores at depths up to 230 m below the day surface, in the permafrost zone, within lignite saturated by natural acetic acid. Our X-ray diffraction study demonstrated that stepanovite and zhemchuzhnikovite exhibit structures found in well-established magnetic and proton-conducting metal oxalate MOFs, consisting of open frameworks with monovalent (Na⁺) and trivalent cations (Al³⁺ or Fe³⁺) as nodes, and are templated by divalent cations retained in framework cavities. Structures of stepanovite and zhemchuzhnikovite, exhibiting almost nanometer-wide and guest-filled apertures and channels, respectively, change the perspective of MOFs as exclusively artificial materials, and represent so far unique examples of open framework architectures in organic minerals.

2017034403 Marcelo, Savio (National University of Catamarca, Institute of Monitoring and Control of Geo-Environmental Degradation, Catamarca, Argentina); Lamas, Cinthia and Adriana, Niz. The use of software for valuation of the glacial and periglacial environment of the Chaschuil Valley, Fiambala, Argentina, using satellites images [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 1273, 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

The Chaschuil Valley is located in Fiambala above 4,500 meters altitude, at the NW of Catamarca Province. This is a long valley, with cold semi-arid climate conditions, and a nighttime temperature below 0°C throughout the year and a large range daily temperature. It shows evidence of permanent ice both as glacier ice and as snow, as well as rock glaciers, frozen ground and permafrost. In the piedmont area there is evidence for wind activity producing both accumulation and of deflation of aeolian sediment. The main channel is the Chaschuil River and its main tributaries are Cazadero Grande, Las Lozas and San Francisco. The Chaschuil Valley is limited to north by the Sierra de San Buenaventura, to the east by the Sierra de Las Planchadas and to the west by the Cordillera de los Andes. For the analysis of the glacial and periglacial environment of the region, technologies and procedures were applied that allow the generation of an innovative method for the cadastral survey of glaciers and periglacial landforms from satellite images. Considering the need to be able to separate and delineate clearly the frozen freshwater bodies existing in the region, and taking as a basis the applications that have the satellites images in the study of extensive zones, an updated methodology is proposed that uses spatial products of national origin (SAOCOM - CONAE) and international origin (LANDSAT, COSMOS, others). To locate areas with features such as glaciers and periglacial environments, the use of satellite images has an important role because they enable the incorporation of legal land objects of the public character to the land registration, provide high resolution basis for landform definition and information on the role of these features in freshwater supply in a region with a raised of water deficit. From the utilization of satellite images is possible to orchestrate a methodology updated to reveal and to register the bodies of ice (glaciers, snow, glaciers of rubble, permafrost, etc.) of the glacier and periglacial region of Chaschuil's Valley. Given that the water present in the glacial and periglacial systems constitute a strategic future resource, it must be more accurately inventoried, identified and registered to guarantee it as natural accessible resource for the use of the future generations, especially as the meltwater detours through a neighboring country. The investigation will be continued by fieldwork for the measurement of points of control in the area, the analysis of the possible systems of projection to using and the choice of the most suitable system.

URL: http://www.americangeosciences.org/sites/default/files/igc/1273.pdf

2017034393 Singhroy, V. (Natural Resources Canada, Canada Centre for Remote Sensing, Ottawa, ON, Canada); Li, J. and Charbonneau, F. High resolution rapid revisit InSAR monitoring of surface deformation [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 1260, 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

Monitoring surface deformation on strategic energy and transportation corridors requires high resolution spatial and temporal InSAR images for mitigation and safety purposes. High resolution air photos, lidar and other satellite images are very useful in areas where the landslides can be fatal. Recently, radar interferometry (InSAR) techniques using more rapid revisit images from several radar satellites are increasingly being used in active deformation monitoring. The Canadian RADARSAT Constellation (RCM) is a three-satellite mission that will provide rapid revisits of four days interferometric (InSAR) capabilities that will be very useful for complex deformation monitoring. For instance, the monitoring of surface deformation due to permafrost activity, complex rock slide motion and steam assisted oil extraction will benefit from this new rapid revisit capability. This paper provide examples of how the high resolution (1-3 m) rapid revisit InSAR capabilities will improve our monitoring of surface deformation and provide insights in understanding triggering mechanisms. We analysed over a hundred high resolution InSAR images over a two year period on geologically different sites with various configurations of topography, geomorphology, and geology conditions. The high resolution InSAR images are effective in characterizing differential motion within these low velocity landslides. Our results show that rapid revisit InSAR acquisitions are required during the combined wet spring and storm events for coastal landslides. Highly fractured slow moving asymmetrical wedge failures on an active rockslide along a railway corridor require InSAR acquisitions throughout the year. Permafrost triggered landslides affecting pipeline corridors require acquisitions during the peak summer thaw season. Deformation triggered by steam injection over the oil sands requires high resolution constant rapid revisit monitoring during the steaming and extraction periods.

URL: http://www.americangeosciences.org/sites/default/files/igc/1260.pdf

2017034373 Vargas-Cordero, I. (Universidad Andres Bello, Vina del Mar, Chile); Tinivella, U.; Villar-Muñoz, L. and Toledo-Rubilar, P. Gas hydrate occurrences from seismic analysis offshore Chile [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 1230, 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

Natural gas hydrates are deposits of water and gas in an ice-like form occurring on continental margins below seafloor and in permafrost. They are stable under relative low temperature and high pressure. Studies of natural gas hydrates normally deal with mining, their spatial distribution, geohazards and climate change. In the last decades, gas hydrate occurrence along the Chilean continental margin has been well documented. Until now, however, few studies have been done to better define the seismic character of the hydrate bearing sediments. To fill this knowledge gap, we performed a detailed velocity analysis by using the pre-stack depth migration methodology on part of multichannel reflection seismic line SO161-40 located offshore Valdivia. Results from the velocity model show a hydrate bearing layer above the BSR, with high velocity (1800 to 2500 m/s), a maximum thickness of 500 m and a free gas bearing layer below the BSR, characterized by low velocity (1600 m/s). A weak reflector at about 100 m below the BSR marks the base of the free gas layer. Particular attention is devoted in analysing the base of the free gas layer. In order to better underline this reflector, we performed a pre-stack time migration that improved the stacked image. Moreover, from Amplitude versus Offset theoretical curves, we know that the reflection amplitude increases for a large offset, as confirmed when comparing the stacked section with near, medium and far offsets. By knowing the BSR depth, the sea floor depth, and the sea bottom temperature from direct measurements, the geothermal gradient was estimated. The resulting geothermal gradient varies from 25 to 45 °C/km. In order to quantify the amount of gas phase, the velocity model was converted into a gas-phase concentration model by using a theoretical approach. The results indicate a range of 5 to 10% of the total volume of gas hydrate concentration, while low concentrations of free gas are detected (0.1 to 0.5% of the total volume). Average concentrations are equal to 8% and 0.4% of the total volume for gas hydrate and free gas respectively, confirming that this area is very interesting from a gas hydrate point of view.

URL: http://www.americangeosciences.org/sites/default/files/igc/1230.pdf

2017035885 Roth, K. (Universität Heidelberg, Institut für Umweltphysik, Heidelberg, Germany). Application of GPR in soil hydrology [abstr.]: in 73. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, Jahrestagung der Deutschen Geophysikalischen Gesellschaft e.V., 73, p. 144, 2013. Meeting: 73. Jahrestagung der Deutschen Geophysikalischen Gesellschaft, March 4-7, 2013, Leipzig, Germany.

URL: http://www.ufz.de/export/data/425/46630_DGG_2013_Tagungsprogramm_und_Abstracts.p ...

2017032022 Dursun, F. (Middle East Technical University, Department of Geological Engineering, Ankara, Turkey) and Topal, T. Freeze thaw resistance of Diyarbakir city walls [abstr.]: in 35th international geological congress; abstracts, International Geological Congress, Abstracts = Congrès Géologique International, Résumés, 35, Abstract 2099, 2016. Meeting: 35th international geological congress, Aug. 27-Sept. 4, 2016, Cape Town, South Africa.

The Diyarbakir Citadel and City walls are appreciated as a masterpiece structural design of human history. Hence, UNESCO World Heritage Committee added the structure into the World Heritage List. It is considered to be a result of different cultures combined from different historical periods. The structure is shaped from the basalts of Karacadag Volcanic Complex. Based on the field surveys two types of basalts used in the Diyarbakir City Walls were identified. These are classified as massive and vesicular basalts. The City Walls reveal some signs of weathering. The freeze-thaw activity plays an important role on the deterioration of the basalt. Therefore, freeze-thaw test is carried out to assess the freeze-thaw resistance of the fresh basalts. Moreover, some physico-mechanical properties such as water absorption, weight loss, effective porosity, dry unit weight, saturation coefficient, uniaxial compressive strength (UCS) and sonic velocity of both massive and vesicular basalts are recorded at different test cycles. The cyclic test results demonstrate that the basalts are adversely affected by the freeze-thaw tests.

URL: http://www.americangeosciences.org/sites/default/files/igc/2099.pdf

Back to the Top

2017036375 Oldenborger, G. A. (Geological Survey of Canada, Ottawa, ON, Canada); LeBlanc, A. M.; Bellehumeur-Génier, O.; Grosset, C.; Holzman, S.; Masson, C. and Tremblay, T. Community workshop on permafrost and landscape change, Rankin Inlet, Nunavut: Open-File Report - Geological Survey of Canada, Rep. No. 8057, 29 p. ( sum.), illus. incl. tables, 24 ref., 2016.

A community workshop on permafrost and landscape change was held in Rankin Inlet, Nunavut from February 1-3, 2016. The workshop consisted of an open house on permafrost research at Natural Resources Canada, educational outreach activities on climate change and permafrost, and a participatory mapping exercise for gathering local and traditional knowledge on permafrost and landscape change in the Rankin Inlet region. The mapping exercise documented observations of landscape features and landscape change that may be related to permafrost and permafrost processes. Observations shared during the participatory mapping exercise are presented as a series of maps keyed to a table of descriptions. Information gathered from the participatory mapping exercise will be interpreted in terms of permafrost conditions in the Rankin Inlet region and workshop results will be used to design and develop research activities and field operations within Natural Resources Canada.

DOI: 10.4095/298806

2017036477 Riedel, M. (Geological Survey of Canada, Sidney, BC, Canada); Hong, J. K.; Jin, Y. K.; Rohr, K. M. M. and Côté, M. M. First results on velocity analyses of multichannel seismic data acquired with the icebreaker RV Araon across the southern Beaufort Sea, offshore Yukon: Current Research - Geological Survey of Canada, Rep. No. 2016-3, 24 p. (French sum.), illus. incl. tables, 2016. ISBN: 978-0-660-05732-3.

One thousand two hundred twenty kilometres of multichannel seismic data were acquired in the Beaufort Sea in 2013 and 2014 to interpret shallow sedimentary structures associated with the upper Cenozoic Iperk and Shallow Bay depositional sequences. Seismic velocity analyses suggest a remarkably consistent regional velocity-depth trend on the slope within the upper 4 s two-way traveltime. A separate velocity trend was not defined beneath the shelf in this region, where data are influenced by the occurrence of permafrost. Deviations from this trend were noted at unconformities including an upper erosional unconformity. The seismic data in the Mackenzie Trough region suggest a different velocity-depth trend within the upper section and the region is marked by a large erosional unconformity, likely the base of the Shallow Bay sequence. Velocity analyses suggest the removal of up to 425 m of overburden; however, this is an overestimate of erosion as differential compaction from the glacial history has not yet been taken into account. In deeper water (>750 m) a bottom-simulating reflector is present, characterized by the occurrence of free gas and a low-velocity zone. Analyses of three fluid-expulsion features on the slope indicate that the Pokak fluid-expulsion feature and the Triple-Mound fluid-expulsion feature are linked to underlying anticline structures. A flat-topped fluid-expulsion feature at the flank of an equivalent anticline was also examined, but the occurrence of shallow gas creates a blank zone beneath this structure. Pronounced changes in the velocity-depth function at these fluid-expulsion features are linked to occurrence of free gas, and/or fluidized mud extrusions.

DOI: 10.4095/298840

2017036370 Smith, S. L.; Ednie, M. and Chartrand, J. Ground thermal data collection along the Alaska Highway corridor (KP1559-1895), Yukon, summer 2015: Open-File Report - Geological Survey of Canada, Rep. No. 8000, 26 p., illus. incl. tables, 25 ref., 2016.

Ground temperature data were acquired in July 2015 from 13 boreholes along the northwestern section of the Alaska Highway corridor between kilometre post (KP) 1559 and KP 1895 near the Alaska border. Mean annual ground temperatures, determined at or near the zero annual amplitude depth, indicate that permafrost temperature in this section of the corridor is generally above -1°C with colder conditions near the Alaska border where permafrost can be as cold as -3°C. Temperatures measured in the upper 1-2 m indicate that permafrost exists at some sites where surface temperatures are above 0°C and where a sufficient thermal offset exists. Although mean annual air temperature in 2014-15 was higher than in 2013-14, there was no significant difference in the ground temperatures between the two years. The information obtained helps characterize regional permafrost conditions in the southern Yukon and informs climate change impact assessments and adaptation planning.

DOI: 10.4095/298769

2017036339 Jin, Y. K. (Korea Polar Research Institute, Incheon, South Korea) and Dallimore, S. R., editors. ARA05C marine research expedition; Canada-Korea-USA Beaufort Sea Geoscience Research Program; summary of 2014 activities: Open-File Report - Geological Survey of Canada, Rep. No. 7999, 100 p., illus., 2016. Individual papers are cited separately.

Expedition ARA05C was a multidisciplinary undertaking conducted in the southern Beaufort Sea on the research ice breaker RV Araon from Aug 30 to Sept 19, 2014. The program was carried out as collaboration between the Korea Polar Research Institute (KOPRI), Geological Survey of Canada (GSC), Monterey Bay Aquarium Research Institute (MBARI), Department of Fisheries and Ocean (DFO) with participation by Bremen University (BARUM). Multiple research experiments were undertaken to study geological processes related to degrading permafrost, fluid flow and degassing, seismostratigraphy, and associated geohazards, of the Beaufort shelf and slope region. In addition, physical and chemical oceanography measurements of the Arctic Ocean were undertaken with linked atmospheric studies from the vessel. The expedition focused on two main research areas in the Canadian Beaufort Sea: the central shelf and slope areas offshore of the Tuktoyaktuk Peninsula and areas offshore of the Mackenzie Trough area.

DOI: 10.4095/297866

2017036355 Piraux, O. (KAVIK-Stantec, Inuvik, NT, Canada); Côté, M. M.; Akagawa, S.; Kawamoto, T.; Seccombe-Hett, P. and Dallimore, S. R. Mallik 7-year drilling waste sump monitoring program; summary report: Open-File Report - Geological Survey of Canada, Rep. No. 8015, variously paginated, illus. incl. tables, 2016.

The Mallik L-38 lease area in the outer Mackenzie Delta has been the site of three historical gas hydrate drilling programs, Mallik 2L-38 conducted in 1998, and Mallik 3L/4L/5L-38 conducted in 2002 and the Mallik gas hydrate production program conducted in the winters of 2007 and 2008. The 1998 and 2002 programs utilized conventional drilling sumps to dispose of drill cuttings and fluids. Of note, an additional drill sump constructed in the winter of 1973 is also at the Mallik site. This sump, which was part of the Mallik L-38 discovery well, was constructed by Imperial Oil Ltd. and is not part of the undertakings described in this report. In 1998 the Japan National Oil Corporation (JNOC) and the Geological Survey of Canada (GSC), Natural Resources Canada (NRCan) collaborated to complete a gas hydrate research program (Dallimore et al. 1999). With JAPEX Canada Ltd. (JAPEX) acting as the operator, the JAPEX/JNOC/GSC Mallik 2L-38 well was drilled and a drilling waste disposal sump, approximately 45 m x 50 m in size was constructed on the lease. This sump is referred as the Mallik 2L-38 Sump. In 2002, a seven-party participant group also led by JNOC and GSC, with JAPEX as the operator (Dallimore and Collett 2005), drilled the JAPEX/JNOC/GSC et al. Mallik 3L-38, 4L-38 and 5L-38 wells. JAPEX Canada Ltd. acted as the operator for this program, constructing a drill sump, approximately 50 m x 55 m in size, was constructed to dispose of the drilling waste generated during drilling of the three wells. This sump is referred as the Mallik 3L/4L/5L-38 Sump. In the winters of 2007 and 2008 a third gas hydrate research program at the Mallik site was led by Japan Oil, Gas and Metals National Corporation (JOGMEC), NRCan and the Aurora Research Institute (ARI) called the JOGMEC/NRCan/ARI Mallik 2007-2008 Gas Hydrate Production Research Well Program. ARI acted as the operator of this program with the Japan Oil Gas and Metals National Corporation and Natural Resources Canada as participants. This program re-entered the 2L-38 and 3L-38 wells without construction of the sumps. All drilling waste material was removed from site and disposed of at an approved facility (Dallimore et al, 2013). As a condition of Water Board License No. N7L1-1817, ARI was required to undertake a 7-year monitoring program at the Mallik 2L-38 and Mallik 3L/4L/5L-38 sumps.

DOI: 10.4095/297895

Back to the Top