scholarly journals Effects of prolonged sedimentation from permafrost degradation on macroinvertebrate drift in Arctic streams

2020 ◽  
Author(s):  
Brianna Levenstein ◽  
Jennifer Lento ◽  
Joseph Culp
Keyword(s):  
Permafrost Degradation ◽  
Arctic Streams ◽  
Macroinvertebrate Drift

MONITORING OF THE THERMOABRASIONAL AND ACCUMULATIVE COASTS NEAR THE UNDERWATER GAS PIPELINE ROUTE ACROSS THE BAYDARATSKAYA BAY, KARA SEA

2017 ◽  
Author(s):  
Nataliya Belova ◽  
Nataliya Belova ◽  
Alisa Baranskaya ◽  
Alisa Baranskaya ◽  
Osip Kokin ◽  
...  
Keyword(s):  
Thermal Regime ◽  
Storm Surges ◽  
Gas Pipeline ◽  
The Arctic ◽  
Yamal Peninsula ◽  
Permafrost Degradation ◽  
Nearshore Zone ◽  
Barrier Beach ◽  
Energy Dissipater ◽  
Pipeline Route

The coasts of Baydaratskaya Bay are composed by loose frozen sediments. At Yamal Peninsula accumulative coasts are predominant at the site where pipeline crosses the coast, while thermoabrasional coast are prevail at the Ural coast crossing site. Coastal dynamics monitoring on both sites is conducted using field and remote methods starting from the end of 1980s. As a result of construction in the coastal zone the relief morphology was disturbed, both lithodynamics and thermal regime of the permafrost within the areas of several km around the sites where gas pipeline crosses coastline was changed. At Yamal coast massive removal of deposits from the beach and tideflat took place. The morphology of barrier beach, which previously was a natural wave energy dissipater, was disturbed. This promoted inland penetration of storm surges and permafrost degradation under the barrier beach. At Ural coast the topsoil was disrupted by construction trucks, which affected thermal regime of the upper part of permafrost and lead to active layer deepening. Thermoerosion and thermoabrasion processes have activated on coasts, especially at areas with icy sediments, ice wedges and massive ice beds. Construction of cofferdams resulted in overlapping of sediments transit on both coasts and caused sediment deficit on nearby nearshore zone areas. The result of technogenic disturbances was widespread coastal erosion activation, which catastrophic scale is facilitated by climate warming in the Arctic.

CRYOGENIC DYNAMICS IN THE COASTAL ZONE OF THE LAPTEV AND EAST SIBERIAN SEAS

2017 ◽  
Author(s):  
Anatoly Gavrilov ◽  
Anatoly Gavrilov ◽  
Elena Pizhankova ◽  
Elena Pizhankova
Keyword(s):  
Coastal Zone ◽  
Permafrost Degradation

We consider the patterns of existence of thermo-abrasion, thermo-denudation and submarine permafrost degradation in the coastal zone of the Laptev and East Siberian seas. The key goal is to assess their role in changing the permafrost conditions along the coastal zone of a few tens of kilometers wide.

Ecology of Arctic Streams and Rivers

2020 ◽  
pp. 181-218
Author(s):  
Alexander D. Huryn
Keyword(s):  
Streams And Rivers ◽  
Arctic Streams

scholarly journals Debris Flows Occurrence in the Semiarid Central Andes under Climate Change Scenario

Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 43
Author(s):  
Stella M. Moreiras ◽  
Sergio A. Sepúlveda ◽  
Mariana Correas-González ◽  
Carolina Lauro ◽  
Iván Vergara ◽  
...  
Keyword(s):  
Climate Change ◽  
Debris Flows ◽  
Environmental Changes ◽  
Urban Expansion ◽  
Central Andes ◽  
Semiarid Region ◽  
Change Scenario ◽  
Permafrost Degradation ◽  
Mountain Areas ◽  
Negative Impacts

This review paper compiles research related to debris flows and hyperconcentrated flows in the central Andes (30°–33° S), updating the knowledge of these phenomena in this semiarid region. Continuous records of these phenomena are lacking through the Andean region; intense precipitations, sudden snowmelt, increased temperatures on high relief mountain areas, and permafrost degradation are related to violent flow discharges. Documented catastrophic consequences related to these geoclimatic events highlight the need to improve their understanding in order to prepare the Andean communities for this latent danger. An amplified impact is expected not only due to environmental changes potentially linked to climate change but also due to rising exposure linked to urban expansion toward more susceptible or unstable areas. This review highlights as well the need for the implementation of preventive measures to reduce the negative impacts and vulnerability of the Andean communities in the global warming context.

Processes and modes of permafrost degradation on the Qinghai-Tibet Plateau

2009 ◽  
Vol 53 (1) ◽  
pp. 150-158 ◽  
Author(s):  
JiChun Wu ◽  
Yu Sheng ◽  
QingBai Wu ◽  
Zhi Wen
Keyword(s):  
Tibet Plateau ◽  
Permafrost Degradation ◽  
Qinghai Tibet Plateau

4D-Quantification of alpine permafrost degradation in a bedrock ridge using multiple inversion schemes and deformation measurements

2021 ◽  
Author(s):  
Maike Offer ◽  
Riccardo Scandroglio ◽  
Daniel Draebing ◽  
Michael Krautblatter
Keyword(s):  
Climate Change ◽  
Mechanical Stability ◽  
Regularization Parameter ◽  
Time Lapse ◽  
Permafrost Degradation ◽  
Thermal Dynamics ◽  
Near Surface ◽  
Data Error ◽  
Near Surface Geophysics ◽  
Thawing Rate

<p>Warming of permafrost in steep rock walls decreases their mechanical stability and could triggers rockfalls and rockslides. However, the direct link between climate change and permafrost degradation is seldom quantified with precise monitoring techniques and long-term time series. Where boreholes are not possible, laboratory-calibrated Electrical Resistivity Tomography (ERT) is presumably the most accurate quantitative permafrost monitoring technique providing a sensitive record for frozen vs. unfrozen bedrock. Recently, 4D inversions allow also quantification of frozen bedrock extension and of its changes with time (Scandroglio et al., in review).</p><p>In this study we (i) evaluate the influence of the inversion parameters on the volumes and (ii) connect the volumetric changes with measured mechanical consequences.</p><p>The ERT time-serie was recorded between 2006 and 2019 in steep bedrock at the permafrost affected Steintälli Ridge (3100 m asl). Accurately positioned 205 drilled-in steel electrodes in 5 parallel lines across the rock ridge have been repeatedly measured with similar hardware and are compared to laboratory temperature-resistivity (T–ρ) calibration of water-saturated samples from the field. Inversions were conducted using the open-source software BERT for the first time with the aim of estimating permafrost volumetric changes over a decade.</p><p>(i) Here we present a sensitivity analysis of the outcomes by testing various plausible inversion set-ups. Results are computed with different input data filters, data error model, regularization parameter (λ), model roughness reweighting and time-lapse constraints. The model with the largest permafrost degradation was obtained without any time-lapse constraints, whereas constraining each model with the prior measurement results in the smallest degradation. Important changes are also connected to the data error estimation, while other setting seems to have less influence on the frozen volume. All inversions confirmed a drastic permafrost degradation in the last 13 years with an average reduction of 3.900±600 m<sup>3</sup> (60±10% of the starting volume), well in agreement with the measured air temperatures increase.</p><p>(ii) Average bedrock thawing rate of ~300 m<sup>3</sup>/a is expected to significantly influence the stability of the ridge. Resistivity changes are especially evident on the south-west exposed side and in the core of the ridge and are here connected to deformations measured with tape extensometer, in order to precisely estimate the mechanical consequences of bedrock warming.</p><p>In summary, the strong degradation of permafrost in the last decade it’s here confirmed since inversion settings only have minor influence on volume quantification. Internal thermal dynamics need correlation with measured external deformation for a correct interpretation of stability consequences. These results are a fundamental benchmark for evaluating mountain permafrost degradation in relation to climate change and demonstrate the key role of temperature-calibrated 4D ERT.</p><p> </p><p>Reference:</p><p>Scandroglio, R. et al. (in review) ‘4D-Quantification of alpine permafrost degradation in steep rock walls using a laboratory-calibrated ERT approach’, <em>Near Surface Geophysics</em>.</p>

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