Permafrost Monthly Alerts (PMAs)

2017099833 Rushlow, Caitlin R. (Idaho State University, Department of Geosciences, Pocatello, ID) and Godsey, Sarah E. Rainfall-runoff responses on Arctic hillslopes underlain by continuous permafrost, North Slope, Alaska, USA: Hydrological Processes, 31(23), p. 4092-4106, illus. incl. 3 tables, sketch map, 51 ref., November 15, 2017.

The Arctic hydrologic cycle is intensifying, as evidenced by increased rates of precipitation, evapotranspiration, and riverine discharge. However, the controls on water fluxes from terrestrial to aquatic systems in upland Arctic landscapes are poorly understood. Upland landscapes account for one third of the Arctic land surface and are often drained by zero-order geomorphic flowpath features called water tracks. Previous work in the region attributed rapid runoff response at larger stream orders to water tracks, but models suggest water tracks are hydrologically disconnected from the surrounding hillslope. To better understand the role of water tracks in upland landscapes, we investigated the surface and subsurface hydrologic responses of 6 water tracks and their hillslope watersheds to natural patterns of rainfall, soil thaw, and drainage. Between storms, both water track discharge and the water table in the hillslope watersheds exhibited diel fluctuations that, when lagged by 5 hr, were temporally correlated with peak evapotranspiration rate. Water track soils remained saturated for more of the summer season than soils in their surrounding hillslope watersheds. When rainfall occurred, the subsurface response was nearly instantaneous, but the water tracks took significantly longer than the hillslopes to respond to rainfall, and longer than the responses previously observed in nearby larger order Arctic streams. There was also evidence for antecedent soil water storage conditions controlling the magnitude of runoff response. Based on these observations, we used a broken stick model to test the hypothesis that runoff production in response to individual storms was primarily controlled by rainfall amount and antecedent water storage conditions near the water track outlet. We found that the relative importance of the two factors varied by site, and that water tracks with similar watershed geometries and at similar landscape positions had similar rainfall-runoff model relationships. Thus, the response of terrestrial water fluxes in the upland Arctic to climate change depends on the non-linear interactions between rainfall patterns and subsurface water storage capacity on hillslopes. Predicting these interactions across the landscape remains an important challenge. Abstract Copyright (2010), John Wiley & Sons, Ltd.

DOI: 10.1002/hyp.11294

2017103569 Euskirchen, Eugénie S. (University of Alaska at Fairbanks, Institute of Arctic Biology, Fairbanks, AK); Edgar, Colin W.; Bret-Harte, M. Syndonia; Kade, Anja; Zimov, Nikita and Zimov, Sergey. Interannual and seasonal patterns of carbon dioxide, water, and energy fluxes from ecotonal and thermokarst-impacted ecosystems on carbon-rich permafrost soils in northeastern Siberia: Journal of Geophysical Research: Biogeosciences, 122(10), p. 2651-2668, illus. incl. 2 tables, 70 ref., October 2017.

Eastern Siberia Russia is currently experiencing a distinct and unprecedented rate of warming. This change is particularly important given the large amounts of carbon stored in the yedoma permafrost soils that become vulnerable to thaw and release under warming. Data from this region pertaining to year-round carbon, water, and energy fluxes are scarce, particularly in sensitive ecotonal ecosystems near latitudinal treeline, as well as those already impacted by permafrost thaw. Here we investigated the interannual and seasonal carbon dioxide, water, and energy dynamics at an ecotonal forested site and a disturbed thermokarst-impacted site. The ecotonal site was approximately neutral in terms of CO₂ uptake/release, while the disturbed site was either a source or neutral. Our data suggest that high rates of plant productivity during the growing season at the disturbed site may, in part, counterbalance higher rates of respiration during the cold season compared to the ecotonal site. We also found that the ecotonal site was sensitive to the timing of the freezeup of the soil active layer in fall, releasing more CO₂ when freezeup occurred later. Both sites showed a negative water balance, although the ecotonal site appeared more sensitive to dry conditions. Water use efficiency at the ecotonal site was lower during warmer summers. Overall, these Siberian measurements indicate ecosystem sensitivity to warmer conditions during the fall and to drier conditions during the growing season and provide a better understanding of ecosystem response to climate in a part of the circumpolar Arctic where current knowledge is weakest. Abstract Copyright (2017), . American Geophysical Union. All Rights Reserved.

DOI: 10.1002/2017JG004070

2017103567 Faucher, Benoit (University of Ottawa, Department of Geography, Environment and Geomatics, Ottawa, ON, Canada); Lacelle, Denis; Davila, Alfonso F.; Pollard, Wayne; Fisher, David and McKay, Christopher P. Physicochemical and biological controls on carbon and nitrogen in permafrost from an ultraxerous environment, McMurdo dry valleys of Antarctica: Journal of Geophysical Research: Biogeosciences, 122(10), p. 2593-2604, illus. incl. 1 table, sketch maps, 45 ref., October 2017.

Little is known about the abundance and source of soil organic carbon and biogeochemical cycling in permafrost soils from the ultraxerous environment of the Dry Valleys of Antarctica. Here we investigate the distribution, source and cycling of organic carbon, total nitrogen and carbonates in the icy permafrost soils of University Valley, Quartermain Mountains. Results indicate that organic carbon content is lowest in icy soils from the perennially cryotic zone (<40 mg g^-1 dry soils) and higher in the icy soils from the seasonally noncryotic zone, where the highest concentrations were found in the warmer-wetter section of the valley and near a frozen pond (up to 313 mg g^-1 dry soils). The d¹³C_org of organic carbon in the icy soils showed that it is derived from the weathering of Beacon Supergroup sandstone that hosts active endolithic communities. The C:N ratios in icy soils formed two populations: one with ratios <5 and the other with ratios near the Redfield ratios. The low C:N ratios suggest that physicochemical processes dominates these soils, as supported by the absence of microbial activity and atmospherically deposited NO₃ with minimal postdeposition modification. The near Redfield C:N ratios can be explained by physical processes (translocation of SOC in the soils from snow meltwater) or balanced microbial activity. The latter is supported by the d¹³C_CaCO3 values of carbonates that suggest a contribution from microbially respired endolith-derived organic matter, providing indirect evidence of heterotrophic activity in permafrost soils from an ultraxerous environment. Abstract Copyright (2017), . American Geophysical Union. All Rights Reserved.

DOI: 10.1002/2017JG004006

2017103566 Mu Cuicui (Lanzhou University, College of Earth and Environmental Sciences, Lanzhou, China); Wu Xiaodong; Zhao Qian; Smoak, Joseph M.; Yang Yulong; Hu Lian; Zhong Wen; Liu Guimin; Xu Haiyan and Zhang Tingjun. Relict mountain permafrost area (Loess Plateau, China) exhibits high ecosystem respiration rates and accelerating rates in response to warming: Journal of Geophysical Research: Biogeosciences, 122(10), p. 2580-2592, illus. incl. 3 tables, sketch map, 64 ref., October 2017.

Relict permafrost regions are characterized by thin permafrost and relatively high temperatures. Understanding the ecosystem respiration rate (ERR) and its relationship with soil hydrothermal conditions in these areas can provide knowledge regarding the permafrost carbon cycle in a warming world. In this study, we examined a permafrost area, a boundary area, and a seasonally frozen ground area within a relict permafrost region on the east edge of the Qinghai-Tibetan Plateau, China. Measurements from July 2015 to September 2016 showed that the mean annual ecosystem CO₂ emissions for the boundary area were greater than the permafrost area. The Q₁₀ value of the ERRs in the seasonally frozen ground area was greater than the permafrost area, indicating that the carbon emissions in the nonpermafrost areas were more sensitive to warming. The 1 year open-top chamber (OTC) warming increased soil temperatures in both the permafrost and seasonally frozen ground areas throughout the year, and the warming increased the ERRs by 1.18 (0.99-1.38, with interquartile range) and 1.13 (0.75-1.54, with interquartile range) mmol CO₂ m^-2 s^-1 in permafrost and seasonally frozen ground areas, respectively. The OTC warming increased annual ERRs by approximately 50% for both permafrost and seasonally frozen ground areas with half the increase occurring during the nongrowing seasons. These results suggest that the ERRs in relict permafrost are high in comparison with arctic regions, and the carbon balance in relict permafrost areas could be greatly changed by climate warming. Abstract Copyright (2017), . American Geophysical Union. All Rights Reserved.

DOI: 10.1002/2017JG004060

2017099491 Raz-Yaseef, Naama (Lawrence Berkeley National Laboratory, Berkeley, CA); Young-Robertson, Jessica; Rahn, Thom; Sloan, Victoria; Newman, Brent; Wilson, Cathy; Wullschleger, Stan D. and Torn, Margaret S. Evapotranspiration across plant types and geomorphological units in polygonal Arctic tundra: Journal of Hydrology, 553, p. 816-825, illus. incl. 2 tables, sketch map, 51 ref., October 2017.

Coastal tundra ecosystems are relatively flat, and yet display large spatial variability in ecosystem traits. The microtopographical differences in polygonal geomorphology produce heterogeneity in permafrost depth, soil temperature, soil moisture, soil geochemistry, and plant distribution. Few measurements have been made, however, of how water fluxes vary across polygonal tundra plant types, limiting our ability to understand and model these ecosystems. Our objective was to investigate how plant distribution and geomorphological location affect actual evapotranspiration (ET). These effects are especially critical in light of the rapid change polygonal tundra systems are experiencing with Arctic warming. At a field site near Barrow, Alaska, USA, we investigated the relationships between ET and plant cover in 2014 and 2015. ET was measured at a range of spatial and temporal scales using: (1) An eddy covariance flux tower for continuous landscape-scale monitoring; (2) An automated clear surface chamber over dry vegetation in a fixed location for continuous plot-scale monitoring; and (3) Manual measurements with a clear portable chamber in approximately 60 locations across the landscape. We found that variation in environmental conditions and plant community composition, driven by microtopographical features, has significant influence on ET. Among plant types, ET from moss-covered and inundated areas was more than twice that from other plant types. ET from troughs and low polygonal centers was significantly higher than from high polygonal centers. ET varied seasonally, with peak fluxes of 0.14 mm h^-1 in July. Despite 24 hours of daylight in summer, diurnal fluctuations in incoming solar radiation and plant processes produced a diurnal cycle in ET. Combining the patterns we observed with projections for the impact of permafrost degradation on polygonal structure suggests that microtopographic changes associated with permafrost thaw have the potential to alter tundra ecosystem ET.

DOI: 10.1016/j.jhydrol.2017.08.036

2017099844 Salvado, Joan A. (Stockholm University, Department of Environmental Science and Analytical Chemistry, Stockholm, Sweden); Broder, Lisa; Andersson, August; Semiletov, Igor P. and Gustafsson, Orjan. Release of black carbon from thawing permafrost estimated by sequestration fluxes in the East Siberian Arctic shelf recipient: Global Biogeochemical Cycles, 31(10), p. 1501-1515, illus. incl. 3 tables, sketch map, 98 ref., October 2017.

Black carbon (BC) plays an important role in carbon burial in marine sediments globally. Yet the sequestration of BC in the Arctic Ocean is poorly understood. Here we assess the concentrations, fluxes, and sources of soot BC (SBC)-the most refractory component of BC-in sediments from the East Siberian Arctic Shelf (ESAS), the World's largest shelf sea system. SBC concentrations in the contemporary shelf sediments range from 0.1 to 2.1 mg g^-1 dw, corresponding to 2-12% of total organic carbon. The ²¹⁰Pb-derived fluxes of SBC (0.42-11 g m^-2 yr^-1) are higher or in the same range as fluxes reported for marine surface sediments closer to anthropogenic emissions. The total burial flux of SBC in the ESAS (~4,000 Gg yr^-1) illustrates the great importance of this Arctic shelf in marine sequestration of SBC. The radiocarbon signal of the SBC shows more depleted yet also more uniform signatures (-721 to -896 ppm; average of -774 ± 62 ppm) than of the non-SBC pool (-304 to -728 ppm; average of -491 ± 163 ppm), suggesting that SBC is coming from an, on average, 5,900 ± 300 years older and more specific source than the non-SBC pool. We estimate that the atmospheric BC input to the ESAS is negligible (~0.6% of the SBC burial flux). Statistical source apportionment modeling suggests that the ESAS sedimentary SBC is remobilized by thawing of two permafrost carbon (PF/C) systems: surface soil permafrost (topsoil/PF; 25 ± 8%) and Pleistocene ice complex deposits (ICD/PF; 75 ± 8%). The SBC contribution to the total mobilized permafrost carbon (PF/C) increases with increasing distance from the coast (from 5 to 14%), indicating that the SBC is more recalcitrant than other forms of translocated PF/C. These results elucidate for the first time the key role of permafrost thaw in the transport of SBC to the Arctic Ocean. With ongoing global warming, these findings have implications for the biogeochemical carbon cycle, increasing the size of this refractory carbon pool in the Arctic Ocean. Abstract Copyright (2017), . American Geophysical Union. All Rights Reserved.

DOI: 10.1002/2017GB005693

2017094160 Hirst, Catherine (Swedish Museum of Natural History, Department of Geosciences, Stockholm, Sweden); Andersson, Per S.; Shaw, Samuel; Burke, Ian T.; Kutscher, Liselott; Murphy, Melissa J.; Maximov, Trofim; Pokrovsky, Oleg S.; Mörth, Carl-Magnus and Porcelli, Don. Characterisation of Fe-bearing particles and colloids in the Lena River basin, NE Russia: Geochimica et Cosmochimica Acta, 213, p. 553-573, illus. incl. 2 tables, sketch map, 99 ref., September 15, 2017. Includes appendices.

Rivers are significant contributors of Fe to the ocean. However, the characteristics of chemically reactive Fe remain poorly constrained, especially in large Arctic rivers, which drain landscapes highly susceptible to climate change and carbon cycle alteration. The aim of this study was a detailed characterisation (size, mineralogy, and speciation) of riverine Fe-bearing particles (>0.22 mm) and colloids (1 kDa-0.22 mm) and their association with organic carbon (OC), in the Lena River and tributaries, which drain a catchment almost entirely underlain by permafrost. Samples from the main channel and tributaries representing watersheds that span a wide range in topography and lithology were taken after the spring flood in June 2013 and summer baseflow in July 2012. Fe-bearing particles were identified, using Transmission Electron Microscopy, as large (200 nm^-1 mm) aggregates of smaller (20-30 nm) spherical colloids of chemically-reactive ferrihydrite. In contrast, there were also large (500 nm^-1 mm) aggregates of clay (illite) particles and smaller (100-200 nm) iron oxide particles (dominantly hematite) that contain poorly reactive Fe. TEM imaging and Scanning Transmission X-ray microscopy (STXM) indicated that the ferrihydrite is present as discrete particles within networks of amorphous particulate organic carbon (POC) and attached to the surface of primary produced organic matter and clay particles. Together, these larger particles act as the main carriers of nanoscale ferrihydrite in the Lena River basin. The chemically reactive ferrihydrite accounts for on average 70 ± 15% of the total suspended Fe in the Lena River and tributaries. These observations place important constraints on Fe and OC cycling in the Lena River catchment area and Fe-bearing particle transport to the Arctic Ocean.

DOI: 10.1016/j.gca.2017.07.012

2017094260 Kovacs, Jozsef (Eotvos Lorand University, Department of Physical and Applied Geology, Budapest, Hungary) and Eross, Anita. Statistically optimal grouping using combined cluster and discriminant analysis (CCDA) on a geochemical data base of thermal karst waters in Budapest: Applied Geochemistry, 84, p. 76-86, illus. incl. 1 table, sketch maps, 53 ref., September 2017.

Budapest, the capital of Hungary, is famous for its abundant thermal waters. The monitoring network of the thermal karst waters of Budapest consists of 27 sampling locations, from which data for six geochemical parameters and temperature were available for the period 1960-2010. Based on this data, the optimal grouping for the sampling locations was sought using combined cluster and discriminant analysis. Furthermore, the homogeneity of the obtained groups, as well as temporal changes in the overall monitoring system were investigated. The seven groups found are in accordance with the previously established hydrogeological conditions, i.e. the grouping can be considered as optimal. The results obtained using combined cluster and discriminant analysis on the geochemical and temperature database of Budapest have important practical implications, since the thermal waters are an intensely used resource. Any artificial intervention will influence locations belonging to the same group, and therefore the optimal grouping of sampling locations will help in the planning of further activities. This case study might serve as an example in other settings where multiple measurements at multiple sampling locations from a monitoring network are available.

DOI: 10.1016/j.apgeochem.2017.05.009

2017094166 Qi, Junyu (University of New Brunswick, Faculty of Forestry and Environmental Management, Fredericton, NB, Canada); Li, Sheng; Qi Yang; Xing, Zisheng and Meng, Fan-Rui. SWAT setup with long-term detailed landuse and management records and modification for a micro-watershed influenced by freeze-thaw cycles: Water Resources Management, 31(12), p. 3953-3974, illus., 62 ref., September 2017. Based on Publisher-supplied data.

In the widely used soil and water assessment tool (SWAT), the standard hydrological response units (HRUs) delineation method has low spatial resolution with respect to model inputs and outputs and renders difficulties in using long-term detailed landuse and management records. In addition, the modified universal soil loss equation (MUSLE) uses a constant K-factor which cannot address seasonal variation in soil erodibility caused by freeze-thaw cycles in cold regions. The current study presents a simple method to incorporate detailed landuse and management inputs in SWAT. The method delineates HRUs based on field boundaries and associates each HRU with a particular field. As a result, long-term detailed records can be incorporated into the SWAT management files. In addition, the existing MUSLE in SWAT was modified by introducing a variable K-factor to address effects of freeze-thaw cycles on soil erosion for cold regions. This modified version of SWAT was calibrated and validated for an agricultural micro-watershed, i.e., Black Brook Watershed in New Brunswick, Canada. The results showed that, compared with the standard HRU-delineation method, field-based HRU-delineation method was able to improve landuse and management practice input accuracy for SWAT and save time and effort for long-term simulation, and provide high resolution outputs in the watershed. As a result, the field-based HRU-delineation method can facilitate decision making not only at the subbasin scale but also at the field scale. In addition, results showed that sediment loading simulation accuracy was improved with the modified-MUSLE compared with the original-MUSLE. Copyright 2017 Springer Science+Business Media B.V. and Springer Science+Business Media Dordrecht

DOI: 10.1007/s11269-017-1718-2

2017093878 Viktorov, A. S. (Russian Academy of Sciences, Sergeyev Institute of Environmental Geology, Moscow, Russian Federation); Kapralova, V. N.; Orlov, T. V.; Trapeznikova, O. N.; Arkhipova, M. V.; Berezin, P. V.; Zverev, A. V.; Panchenko, E. N. and Sadkov, S. A. Consistent patterns of the size distribution of thermokarst lakes: Doklady Earth Sciences, 474(2), p. 692-694, illus. incl. 1 table, sketch map, 7 ref., June 2017.

The purpose of this work is to study empirically the patterns of size distribution of thermokarst lakes within lacustrine thermokarst plains. Investigations were performed at 16 sites with various geomorphological, geocryological, and physical geographical conditions (Kolyma Lowland, Western Siberia, Lena River valley, Alaska). The accordance of the distribution area with the lognormal and exponential laws, and the accordance of the average diameter distribution with the normal law have been tested; the tested laws of distribution resulted from previous investigations. The results have shown that the lognormal law of distribution of thermokarst lake areas is valid for the vast majority of cases, and the other types of distribution are inconsistent with empirical data. This evidence favors the development pattern for lacustrine thermokarst plains, when thermokarst processes started simultaneously and the rate of lake growth was proportional to the density of heat loss through the side surface. Copyright 2017 Pleiades Publishing, Ltd.

DOI: 10.1134/S1028334X17060162

2017099877 Anonymous. Transactions of the International Permafrost Association: Permafrost and Periglacial Processes, 27(4), p. 323-389, illus., December 2016. Individual papers within scope are cited separately.

2017099879 Arenson, Lukas U. (BGC Engineering, Vancouver, BC, Canada); Kaab, Andreas and O'Sullivan, Antóin. Detection and analysis of ground deformation in permafrost environments: in Transactions of the International Permafrost Association, Permafrost and Periglacial Processes, 27(4), p. 339-351, illus. incl. 1 table, 75 ref., December 2016.

In situ monitoring of periglacial dynamics is essential for the study of periglacial morphology and the design of mitigation and adaptation measures for infrastructure in permafrost zones. Evaluation of future effects of climate change on and from the periglacial environment requires understanding of surficial and internal deformation processes. Monitoring of internal deformation is still uncommon, primarily because of high costs. By contrast, major advancements in remote-sensing technologies allow detailed assessment of surface deformation for large study areas. Technological advancements are anticipated to enhance spatial and temporal resolution, lighten sensors and improve unmanned aerial vehicles technology. The last of these will facilitate and reduce costs for data collection in remote areas under harsh climatic conditions. Increasing application of Structure-from-Motion, a photogrammetric image analysis technique, is anticipated, due to its precision, resolution, ease of usage and low cost. Copyright Copyright 2016 John Wiley & Sons, Ltd.

DOI: 10.1002/ppp.1932

2017099881 Christiansen, Hanne H. (University Centre in Svalbard, Department of Arctic Geology, Longyearbyen, Svalbard and Jan Mayen Islands); Matsuoka, Norikazu and Watanabe, Tatsuya. Progress in understanding the dynamics, internal structure and palaeoenvironmental potential of ice wedges and sand wedges: in Transactions of the International Permafrost Association, Permafrost and Periglacial Processes, 27(4), p. 365-376, illus., 54 ref., December 2016.

A review of recent progress in understanding the dynamics, internal structure and palaeoenvironmental potential of ice wedges and sand wedges is presented, based on literature published between 2008 and 2015. Ice wedges constitute the most ice-rich and widespread periglacial landform in permafrost lowlands. Thus, progress in understanding the processes associated with them, using a large variety of direct and indirect field and remote sensing methods, is important, particularly in a changing climate with increased potential for ice-wedge degradation. Ice-wedge polygons have been found to control microclimate, hydrology and greenhouse gas fluxes from permafrost. New technologies have allowed the identification of more fossil polygons, increasing their role in reconstructing periglacial conditions. Study of ice-wedge casts, sand wedges and ice wedges has improved palaeoenvironmental reconstruction, particularly from the last glacial period and the Holocene, of changes to these landforms in both present and former permafrost areas. Polygons on Mars have recently attracted considerable attention, primarily due to increased remote sensing capabilities and even on-site investigations, which identify ice in these landforms. Copyright Copyright 2016 John Wiley & Sons, Ltd.

DOI: 10.1002/ppp.1920

2017099880 Doré, Guy (Laval University, Department of Civil and Water Engineering, Quebec City, QC, Canada); Niu Fujun and Brooks, Heather. Adaptation methods for transportation infrastructure built on degrading permafrost: in Transactions of the International Permafrost Association, Permafrost and Periglacial Processes, 27(4), p. 352-364, illus. incl. 1 table, 48 ref., December 2016.

Climate warming since the second half of the 20^th century has begun to significantly impact infrastructure integrity in permafrost environments and has already resulted in expensive maintenance operations. Engineers in countries with permafrost are actively working to adapt the design of structures to degrading permafrost conditions. Here, we review permafrost degradation processes and their geotechnical impacts. We also summarise mitigation techniques for protecting transportation infrastructure built on permafrost and for preventing permafrost degradation near these facilities based on the results of field and laboratory tests, numerical simulations and engineering practices on such infrastructure. We draw four conclusions: (1) climate warming and local surface changes have caused permafrost degradation, and resulted in instability and damage leading to infrastructure maintenance and repair; (2) passive cooling methods, including high-albedo surfacing, sun-sheds, air convection embankments, air ducts, heat drains and thermosyphons, have shown consistent cooling effects, if designed appropriately; (3) mitigation and adaptation methods are more expensive than conventional construction techniques as shown by construction cost data for a test site in Canada; and (4) the influence of continued climate warming on permafrost and infrastructure design must be considered within the design of new or rehabilitated infrastructure and within the context of the infrastructure's service life. Copyright Copyright 2016 John Wiley & Sons, Ltd.

DOI: 10.1002/ppp.1919

2017099882 Gilbert, Graham L. (University Centre in Svalbard, Department of Arctic Geology, Longyearbyen, Svalbard and Jan Mayen Islands); Kanevskiy, Mikhail and Murton, Julian B. Recent advances (2008-2015) in the study of ground ice and cryostratigraphy: in Transactions of the International Permafrost Association, Permafrost and Periglacial Processes, 27(4), p. 377-389, illus. incl. sketch map, 50 ref., December 2016.

Cryostratigraphy involves the description, interpretation and correlation of ground-ice structures (cryostructures) and their relationship to the host deposits. Recent advances in the study of ground ice and cryostratigraphy concern permafrost aggradation and degradation, massive-ice formation and evaluation of ground-ice content. Field studies have increased our knowledge of cryostructures and massive ground ice in epigenetic and syngenetic permafrost. Epigenetic permafrost deposits are relatively ice-poor and composed primarily of pore-filled cryostructures, apart from an ice-enriched upper section and intermediate layer. Syngenetic permafrost deposits are commonly identified from cryostructures indicative of an aggrading permafrost table and are characterised by a high ice content, ice-rich cryofacies and nested wedge ice. Degradation of ice-rich permafrost can be marked by thaw unconformities, truncated buried ice wedges, ice-wedge pseudomorphs and organic-rich 'forest beds'. Studies of massive ground ice have focused on wedge ice, thermokarst-cave ice, intrusive ice and buried ice. Significant advances have been made in methods for differentiating between tabular massive-ice bodies of glacier and intrasedimental origin. Recent studies have utilised palynology, isotope geochemistry and hydrochemistry, in addition to sedimentary and cryostratigraphic analyses. The application of remote sensing techniques and laboratory methods such as computed tomography scanning has improved estimations of the ice content of frozen sediments. Copyright Copyright 2016 John Wiley & Sons, Ltd.

DOI: 10.1002/ppp.1912

2017099878 Jorgenson, Mark Torre (Alaska Ecoscience, Fairbanks, AK) and Grosse, Guido. Remote sensing of landscape change in permafrost regions: in Transactions of the International Permafrost Association, Permafrost and Periglacial Processes, 27(4), p. 324-338, illus. incl. sketch map, 152 ref., December 2016.

Amplification of global warming in Arctic and boreal regions is causing significant changes to permafrost-affected landscapes. The nature and extent of the change is complicated by ecological responses that take place across strong gradients in environmental conditions and disturbance regimes. Emerging remote sensing techniques based on a growing array of satellite and airborne platforms that cover a wide range of spatial and temporal scales increasingly allow robust detection of changes in permafrost landscapes. In this review, we summarise recent developments (2010 - 15) in remote sensing applications to detect and monitor landscape changes involving surface temperatures, snow cover, topography, surface water, vegetation cover and structure, and disturbances from fire and human activities. We then focus on indicators of degrading permafrost, including thermokarst lakes and drained lake basins, thermokarst bogs and fens, thaw slumps and active-layer detachment slides, thermal erosion gullies, thermokarst pits and troughs, and coastal erosion and flooding. Our review highlights the expanding sensor capabilities, new image processing and multivariate analysis techniques, enhanced public access to data and increasingly long image archives that are facilitating novel insights into the multi-decadal dynamics of permafrost landscapes. Remote sensing methods that appear especially promising for change detection include: repeat light detection and ranging, interferometric synthetic aperture radar and airborne geophysics for detecting topographic and subsurface changes; temporally dense analyses at high spatial resolution; and multi-sensor data fusion. Remotely sensed data are also becoming used more frequently as driving parameters in permafrost model and mapping schemes. Copyright Copyright 2016 John Wiley & Sons, Ltd.

DOI: 10.1002/ppp.1914

2017093285 Vasil'chuk, Yu. K. (Moscow State University, Moscow, Russian Federation); Podborny, Ye. Ye.; Budantseva, N. A.; Vasil'chuk, A. C.; Sullina, A. N. and Chizhova, Ju. N. d¹⁸O and dD variations in Holocene massive ice in the Sabettayakha river mouth, northern Yamal Peninsula: Doklady Earth Sciences, 470(2), p. 1086-1092, illus. incl. 2 tables, 13 ref., October 2016.

The conditions of formation of massive ice near the South Tambey gas-condensate field in northern Yamal Peninsula are studied. It is shown that massive ice bodies up to 4.5 m thick occur in the Holocene deposits of the high laida and the first terrace. Therefore, they cannot be the remains of glaciers; they are ground ice formations. All three types of massive ice have quite various isotopic compositions: the values of dD range from-107 to-199.7, and d¹⁸O from -15.7 to -26.48 ppm. Such a significant differentiation in isotopic composition is a result of cryogenic fractionation in a freezing water-saturated sediment. The most negative isotope values are even lower in this Holocene massive ice than in the Late Pleistocene ice-wedge ice of Yamal Peninsula. Copyright 2016 Pleiades Publishing, Ltd.

DOI: 10.1134/S1028334X16100172

2017093104 Lee, Jin-Yong (Kangwon National University, Department of Geology, Chuncheon, South Korea); Lim, Hyoun Soo and Yoon, Ho Il. Thermal characteristics of soil and water during summer at King Sejong Station, King George Island, Antarctica: Geosciences Journal (Seoul), 20(4), p. 503-516, sketch map, 53 ref., August 2016. Based on Publisher-supplied data.

Soil temperatures, water temperatures, and weather parameters were monitored at a variety of locations in the vicinity of King Sejong station, King George Island, Antarctica, during summer 2010-2011. Thermal characteristics of soil and water were analysed using time-series analyses, apparent thermal diffusivity (ATD), and active layer thickness. The temperatures of pond water and nearby seawater showed the distinctive diurnal variations and correlated strongly with solar radiation (r = 0.411-0.797). Soil temperature (0.1-0.3 m depth) also showed diurnal fluctuations that decreased with depth and were directly linked to air temperature (r = 0.513-0.783) rather than to solar radiation; correlation decreased with depth and the time lag in the response increased by 2-3 hours per 0.1 m of soil depth. Owing to the lack of snow cover, summertime soil temperature was not decoupled from air temperature. Estimated ATD was between 0.022 and 29.209 mm²/sec, showed temporal and spatial variations, and correlated strongly with soil moisture content. The maximum estimated active layer thickness in the study area was a 41-70 cm, which is consistent with values reported in the previous work. Copyright 2016 The Association of Korean Geoscience Societies and Springer-Verlag Berlin Heidelberg

DOI: 10.1007/s12303-016-0026-9

2017101701 Guo Donglin (Chinese Academy of Sciences, Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Beijing, China) and Sun Jianqi. Permafrost thaw and associated settlement hazard onset timing over the Qinghai-Tibet engineering corridor: International Journal of Disaster Risk Science, 6(4), p. 347-358, illus., 56 ref., December 2015.

In permafrost areas, the timing of thermal surface settlement hazard onset is of great importance for the construction and maintenance of engineering facilities. Future permafrost thaw and the associated thermal settlement hazard onset timing in the Qinghai-Tibet engineering corridor (QTEC) were analyzed using high-resolution soil temperature data from the Community Land Model version 4 in combination with multiple model and scenario soil temperature data from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Compared to the standard frozen ground map for the Tibetan Plateau and ERA-Interim data, a multimodel ensemble reproduces the extent of permafrost and soil temperature change in the QTEC at a 1 m depth from 1986-2005. Soil temperature and active layer thickness increase markedly during 2006-2099 using CMIP5 scenarios. By 2099, the ensemble mean soil temperature at 15 m depth will increase between 1.0 and 3.6°C in the QTEC. Using crushed-rock revetments can delay the onset of thermal settlement hazard for colder permafrost areas by approximately 17 years in the worst case scenario of RCP8.5. Nearly one-third of the area of the QTEC exhibits settlement hazard as early as 2050, and half of this one-third of the area is traversed by the Qinghai-Tibet highway/railway, a situation that requires more planning and remedial attention. Simulated onsets of thermal settlement hazard correspond well to the observed soil temperature at 15 m depth for seven grid areas in the QETC, which to some extent indicates that these timing estimates are reasonable. This study suggests that climate model-based timing estimation of thermal settlement hazard onset is a valuable method, and that the results are worthy of consideration in engineering design and evaluation. Copyright 2015 The Author(s)

DOI: 10.1007/s13753-015-0072-3

2017097541 Shmakova, L. A. (Russian Academy of Sciences, Institute of Physicochemical and Biological Problems of Soil Science, Pushchino, Russian Federation) and Rivkina, E. M. Viable eukaryotes of the phylum Amoebozoa from the Arctic permafrost: Paleontological Journal, 49(6), p. 572-577, illus. incl. 1 table, sketch map, 23 ref., November 2015.

Viable amoeboid protists were isolated from the Arctic Late Pleistocene and Holocene permafrost sediments many of them belong to new species. The diversity of amoebae in the permafrost is rather low in comparison with that of modern tundra soils. The genus Acanthamoeba appears most widespread in the permafrost sediments under study. The amoebae under study are stable with reference to stressful effects; the cysts of fossil amoebae examined successfully survived under conditions of the free space. Copyright 2015 Pleiades Publishing, Ltd.

DOI: 10.1134/S003103011506012X

2017101693 Hiyama, Tetsuya (Nagoya University, Hydrospheric Atmospheric Research Center, Nagoya, Japan). Changes in water environments and social adaptation under global warming at permafrost region in eastern Siberia; an international-interdisciplinary research to propose adaptation strategies: in Role of hydrological sciences to international academic researchers and contributions (Onodera, Shin-ichi, prefacer; et al.), Nihon Suimon Kagaku Kaishi = Journal of Japanese Association of Hydrological Sciences, 45(3), p. 61-72, (Japanese) (English sum.), illus. incl. sketch map, 22 ref., October 2015.

Global warming in the Arctic circumpolar region is likely transforming Siberian permafrost ecosystem through changing water cycles and water environments. Human inhabitants, who have adapted to great changes in social structure and environment in the past, are being forced to adapt again. This paper introduces brief summaries and outcomes on spring- and summer-river floods of the Lena River in eastern Siberia and those impacts to local inhabitants as well as the social adaptation, derived from a research project (C-07) of the Research Institute for Humanity and Nature (RIHN), entitled "Global Warming and the Human-Nature Dimension in Siberia: Social Adaptation to the Changes of the Terrestrial Ecosystem, with an Emphasis on Water Environments". In this project, we have strongly investigated perceptions of local peoples and local governmental adaptation strategies for both spring- and summer-river floods of the Lena river. We additionally deliberate how Japanese Association of Hydrological Sciences (JAHS) should contribute to "Science for Society" in future.

2017097628 Takami, Masazo (Hokkaido Geological Survey, Sapporo, Japan); Tsuchiya, Fujio and Yamaguchi, Satoru. Electrical prospecting for seasonally frozen ground; Part 2, Temporal variation of frozen ground inferred from two dimensional resistivity modelling: Butsuri-Tansa = Geophysical Exploration, 68(4), p. 289-303, (Japanese) (English sum.), illus. incl. 3 tables, 27 ref., 2015.

In cold areas such as Hokkaido in Japan, underground water freezes in winter to produce frozen soil, while it thaws to become a liquid in other seasons. The ground in this situation is called seasonally frozen ground. Frozen ground causes damages to the ground, roads and ground water pipes. On agricultural land, freezing of the ground results in poor drainage and slows the rise in soil temperature during the spring. Furthermore, freezing promotes slope failure on bare land. Meanwhile, the thawing process generates cracks and depressions in road surfaces. It is thus important to understand temporal variations in the location and expanse of frozen regions for the maintenance of construction and prevention of disasters. We made measurements of air temperature, soil temperature, frozen depth, and resistivity for 5 years at Obihiro in Hokkaido, which is a Japanese prefecture known to suffer deep freezing of the soil. To clarify spatial and temporal variations in the frozen region, a series of two-dimensional resistivity analyses were conducted approximately every 2 weeks during the period from November 5, 1995 to May 1, 1996, which covers the whole period from the beginning of freezing to the end of thawing. In the freezing process, highly resistive regions formed discretely in a shallow layer and extended deeply as the soil temperature decreased. In the thawing process, the resistivity structure around the boundary between frozen and unfrozen regions changed drastically between the days before and after the date on which the maximum frozen depth was recorded by the frozen depth meter. As thawing proceeded, resistivity in the highly resistive regions decreased by factors ranging from 10 to 100, and these 'moderately' resistive regions moved both laterally and in the deep direction, before finally vanishing.

2017097484 Kedzia, Stanislaw (Polish Academy of Sciences, Institute of Geography and Spatial Organisation, Cracow, Poland). Are there any active rock glaciers in the Tatra Mountains?: Studia Geomorphologica Carpatho-Balcanica, 48, p. 5-16, illus. incl. geol. sketch map, 30 ref., September 1, 2014.

Research on rock glaciers have been conducted in the Tatra Mountains for about 100 years. About 30 years ago, there were papers suggesting that part of the Tatra rock glaciers was formed during the Little Ice Age. About 20 years ago, permafrost was discovered in the mountains. This discovery marked the beginning of research on the activity of rock glaciers. Ten years ago, a study was carried out on the rock glacier near the Velke Hincovo Pleso lake, which excluded any activity of this glacier in the last few hundred years, despite the high probability of the existence of permafrost in it. The following paper presents the results of lichenometric dating conducted for the activity of rock glaciers in the Swistowka Roztocka and the Buczynowa valleys.

DOI: 10.1515/sgcb-2015-0001

2017097487 Starkel, Leszek (Polish Academy of Sciences Institute of Geography and Spatial Organization Department of Geoenvironmental Research, Krakow, Poland). The Quaternary transformation of older inherited mountain landscapes: Studia Geomorphologica Carpatho-Balcanica, 48, p. 53-60, illus. incl. sects., geol. sketch maps, 34 ref., September 1, 2014.

The Quaternary transformation of the inherited mountain relief was controlled by three factors: cyclic climatic changes, resistance of the substratum and neotectonic uplift. Cyclic climatic fluctuations in the majority of European mountains were reflected in the alternation of interglacial and cold stages, the former characterized by a dominance of forest and chemical weathering, the latter by permafrost, solifluction, wind activity and, at higher elevations, by glacier advances. The transitional phases played an important role as periods of re-establishment of water circulation and transfer of regolith and sediment, formed during the previous cold or interglacial stage. The rates of degradation of inherited planation surfaces and slopes depend on bedrock resistance. In the case of less resistant flysch deposits, degradation during a single (last) cold stage reached 10 metres. Therefore, the higher planation levels may have been either better preserved on more resistant bedrock or even emphasized by cryoplanation processes. The lowest piedmont developed on less resistant beds was lowered to 50 m. In the young mountains, the Quaternary uplift may have played an additional role. In the case of uplift reaching or exceeding several hundred metres, the former fluvial forms were shifted to the cryonival or even nival (glacial) vertical zone where they became entirely transformed.

DOI: 10.1515/sgcb-2015-0004

2017095225 Nussbaumer, S. (University of Zurich, Department of Geography, Zurich, Switzerland); Schaub, Yvonne; Huggel, C. and Walz, A. Risk estimation for future glacier lake outburst floods based on local land-use changes: Natural Hazards and Earth System Sciences (NHESS), 14(6), p. 1611-1624, illus. incl. 5 tables, geol. sketch maps, 66 ref., June 2014.

Effects of climate change are particularly strong in high-mountain regions. Most visibly, glaciers are shrinking at a rapid pace, and as a consequence, glacier lakes are forming or growing. At the same time the stability of mountain slopes is reduced by glacier retreat, permafrost thaw and other factors, resulting in an increasing landslide hazard which can potentially impact lakes and therewith trigger far-reaching and devastating outburst floods. To manage risks from existing or future lakes, strategies need to be developed to plan in time for adequate risk reduction measures at a local level. However, methods to assess risks from future lake outbursts are not available and need to be developed to evaluate both future hazard and future damage potential. Here a method is presented to estimate future risks related to glacier lake outbursts for a local site in southern Switzerland (Naters, Valais). To generate two hazard scenarios, glacier shrinkage and lake formation modelling was applied, combined with simple flood modelling and field work. Furthermore, a land-use model was developed to quantify and allocate land-use changes based on local-to-regional storylines and three scenarios of land-use driving forces. Results are conceptualized in a matrix of three land-use and two hazard scenarios for the year 2045, and show the distribution of risk in the community of Naters, including high and very high risk areas. The study underlines the importance of combined risk management strategies focusing on land-use planning, on vulnerability reduction, as well as on structural measures (where necessary) to effectively reduce future risks related to lake outburst floods.

URL: http://www.nat-hazards-earth-syst-sci.net/14/1611/2014/nhess-14-1611-2014.pdf

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2017096415 Andrews, John R. (Texas Bureau of Economic Geology, Austin, TX); Paine, Jeffrey G. and Young, Michael H. Geomorphic characterization of thermokarst lakes on the North Slope, Alaska [abstr.]: in Geological Society of America, South-Central Section, 51st annual meeting, Abstracts with Programs - Geological Society of America, 49(1), Abstract no. 7-10, 2017. Meeting: Geological Society of America, South-Central Section, 51st annual meeting, March 13-14, 2017, San Antonio, TX.

Thermokarst lakes on Alaska's North Slope serve as carbon sinks, overwintering fish repositories, and water sources for extraction industries. Due to their inaccessibility, thermokarst lakes have long been targets for remote sensing efforts, from WWII-era aerial photography to spaceborne radar imaging to airborne lidar. Though recent advances in lidar technology-specifically the ability to capture bathymetric topography with water-penetrating lasers-have provided unprecedented levels of data quality, from which we can gain insights into thermokarst lake geomorphology, software to process and analyze the data are insufficient or nonexistent. To address this gap in analytical ability, we developed algorithms to extract information, including statistical assessments, using terrestrial and bathymetric data collected over 1200 km² of the Alaskan North Slope, including 7000+ imaged lakes and adjacent terrain. The analytical toolkit imports rasterized topographic, bathymetric, and water surface lidar data; identifies discrete waterbodies; and, calculates geomorphic statistics for each waterbody including staggered volumes, area, elongation, orientation, fetch, bank height, elliptic fit, and the presence, length, and orientation of sublittoral bars. A rigorous comparison between our results and those compiled via traditional methods support our contention that bathymetric lidar is an excellent tool for cost-effective geomorphic characterization of thermokarst lakes. The algorithms are also flexible enough to be used in warmer weather environments, such as in Texas, including reservoirs, ponds, and river reaches. These findings and potential future uses will be discussed.

2017096367 Moore, Collin Scott (University of Louisiana at Lafayette, School of Geosciences, Lafayette, LA) and Schubert, Brian A. Seasonal temperatures in the arctic during the late Pleistocene determined using high-resolution oxygen isotope measurements across fossil wood [abstr.]: in Geological Society of America, South-Central Section, 51st annual meeting, Abstracts with Programs - Geological Society of America, 49(1), Abstract no. 2-8, 2 ref., 2017. Meeting: Geological Society of America, South-Central Section, 51st annual meeting, March 13-14, 2017, San Antonio, TX.

Cellulose is resistant to degradation on Geologic timescales and provides a reliable record of the oxygen isotope composition of meteoric water (d¹⁸O_MW). A strong empirical relationship between the d¹⁸OMW value and temperature has been observed in modern settings, allowing researchers to reconstruct mean annual temperature via measurements of the d¹⁸O value of cellulose (d¹⁸O_cell). Here we present high-resolution intra-annual d¹⁸O_cell measurements across fossil growth rings in mummified wood collected from late Pleistocene sediments (~50,000 to 42,000 ¹⁴C BP) within the Yedoma Silt Ice Complex at Duvanny Yar in far northeastern Siberia. These data are used to quantify year-to-year changes in seasonal temperatures at the site, including warm and cold month mean temperatures (T_max and T_min, respectively). Our results suggest T_max=6.9±2.9°C (average ±1s) and T_min=-37.7±3.0°C during the late Pleistocene, which is ~3-6°C colder than today's values (modern: T_max=13.1±2.1°C, T_min=-34.8±2.6°C). Assuming a normal distribution for monthly temperatures similar to modern continental climates, we calculate that above-freezing mean monthly temperatures occurred in ~1.7 fewer months during the late Pleistocene than today. These cold conditions allowed for the Arctic to act as a significant carbon sink during the late Pleistocene despite shorter growing seasons compared to today (Parmentier et al., 2011; Strauss et al., 2012). Extrapolation to current Arctic warming suggests that increased temperatures will allow for longer periods of net carbon release from Arctic soils each summer, despite increased photosynthesis. Parmentier, F. J. W., M. K. van der Molen, J. van Huissteden, S. A. Karsanaev, A. V. Kononov, D. A. Suzdalov, T. C. Maximov, and A. J. Dolman (2011), Longer growing seasons do not increase net carbon uptake in the northeastern Siberian tundra, J. Geophys. Res., 16, G04013, doi:10.1029/2011JG001653. Strauss, J., L. Schirrmeister, S. Wetterich, A. Borchers, and S. P. Davydov (2012), Grain-size properties and organic-carbon stock of Yedoma Ice Complex permafrost from the Kolyma lowland, northeastern Siberia, Global Biogeochem. Cycles, 26, GB3003, doi:10.1029/2011GB004104.

2017096527 Schorghofer, Norbert (University of Hawaii at Manoa, Institute for Astronomy, Honolulu, HI); Leopold, Matthias; Martin, Jake; Morelli, Amanda and Yoshikawa, Kenji. Permafrost and perched groundwater on the summit plateau of Maunakea Volcano, Hawaii [abstr.]: in Geological Society of America, Cordilleran Section, 113th annual meeting, Abstracts with Programs - Geological Society of America, 49(4), Abstract no. 46-1, 2017. Meeting: Geological Society of America, Cordilleran Section, 113th annual meeting, May 23-25, 2017, Honolulu, HI.

Sporadic permafrost in cinder cones near the summit of Maunakea (4,207m, 19.82N) persists near the warm climatic extreme where mountain permafrost has ever been found. Over the period 2012-2016 we have investigated ice and water bodies in cinder cones on the summit plateau using unobtrusive techniques, such as temperature monitoring, shallow geophysical surveys, and previously untapped historical documents. Electrical Resistivity Tomography and Ground Penetrating Radar surveys reveal that two subsurface ice bodies are still present on Maunakea, but one has retreated in volume by an order of magnitude between 1973 and 2015. A second larger ice body is at least 50m wide, but both are expected to continue to degrade due to global climate warming. We have also reconstructed the history of snow cover from historical records, and identified recent time periods when the permafrost may still have been in equilibrium with the climate. No permafrost was found at Lake Waiau, a well-known perennial lake in the summit region (3,970m), nor at a previously undocumented episodic puddle of water at another cinder cone (Puupohaku) at ~4,000m. Both of these bodies of standing water imply the presence of impermeable layers, which are apparently not uncommon in cinder cones, in an otherwise porous volcanic surface. Impermeable layers are also responsible for a newly discovered perched water reservoir east of the lake that can store water volumes larger than the shallow lake itself. A larger survey of the summit area turned up no additional permafrost bodies, so we are likely witnessing the last permafrost in Hawaii.

2017093766 Shabanloui, Akbar (University of Hannover, Institute of Geodesy, Hannover, Germany) and Müller, Jürgen. Mass variations in the Siberian permafrost region based on new GRACE results and auxiliary modeling: in IGFS 2014; proceedings of the 3rd international gravity field service (Jin, Shuanggen, editor; et al.), International Association of Geodesy Symposia, 144, p. 189-196, illus. incl. sketch map, 37 ref., 2016. Meeting: 3rd international gravity field service (IGFS), June 30-July 6, 2014, Shanghai, China.

DOI: 10.1007/1345_2015_186

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