scholarly journals Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia

2015 ◽  
Vol 9 (4) ◽  
pp. 3741-3775 ◽  
Author(s):  
P. Overduin ◽  
S. Wetterich ◽  
F. Günther ◽  
M. N. Grigoriev ◽  
G. Grosse ◽  
...  
Keyword(s):  
Sea Level ◽  
Coastal Erosion ◽  
Solute Concentration ◽  
The Arctic ◽  
Laptev Sea ◽  
East Siberia ◽  
Concentration Gradients ◽  
Degradation Rates ◽  
A Site

Abstract. Coastal erosion and relative sea-level rise transform terrestrial landscapes into marine environments. In the Arctic, these processes inundate terrestrial permafrost with seawater and create submarine permafrost. Permafrost begins to warm under marine conditions, which can destabilize the sea floor and may release greenhouse gases. We report on the transition of terrestrial to submarine permafrost at a site where the timing of inundation can be inferred from the rate of coastline retreat. On Muostakh Island in the central Laptev Sea, East Siberia, changes in annual coastline position have been measured for decades and vary highly spatially. We hypothesize that these rates are inversely related to the inclination of the upper surface of submarine ice-bonded permafrost (IBP) based on the consequent duration of inundation with increasing distance from the shoreline. We compared rapidly eroding and stable coastal sections of Muostakh Island and find permafrost-table inclinations, determined using direct current resistivity, of 1 and 5 %, respectively. Determinations of submarine IBP depth from a drilling transect in the early 1980s were compared to resistivity profiles from 2011. Based on boreholes drilled in 1982–1983, the thickness of unfrozen sediment overlying the IBP increased from 0 up to 14 m below sea level with increasing distance from the shoreline. The geoelectrical profiles showed thickening of the unfrozen sediment overlying ice-bonded permafrost over the 28 years since drilling took place. Parts of our geoelectrical profiles trace permafrost flooded, and showed that IBP degradation rates decreased from over 0.6 m a−1 following inundation to around 0.1 m a−1 as the duration of inundation increased to 250 years. We discuss that long-term rates are expected to be less than these values, as the depth to the IBP increases and thermal and pore water solute concentration gradients over depth decrease. For this region, it can be summarized that recent increases in coastal erosion rate and longer-term changes to benthic temperature and salinity regimes are expected to affect the depth to submarine permafrost, leading to coastal regions with shallower IBP.

scholarly journals Coastal dynamics and submarine permafrost in shallow water of the central Laptev Sea, East Siberia

2016 ◽  
Vol 10 (4) ◽  
pp. 1449-1462 ◽  
Author(s):  
Pier Paul Overduin ◽  
Sebastian Wetterich ◽  
Frank Günther ◽  
Mikhail N. Grigoriev ◽  
Guido Grosse ◽  
...  
Keyword(s):  
Coastal Erosion ◽  
Solute Concentration ◽  
The Arctic ◽  
Laptev Sea ◽  
Permafrost Degradation ◽  
East Siberia ◽  
Concentration Gradients ◽  
Study Region ◽  
Degradation Rates ◽  
A Site

Abstract. Coastal erosion and flooding transform terrestrial landscapes into marine environments. In the Arctic, these processes inundate terrestrial permafrost with seawater and create submarine permafrost. Permafrost begins to warm under marine conditions, which can destabilize the sea floor and may release greenhouse gases. We report on the transition of terrestrial to submarine permafrost at a site where the timing of inundation can be inferred from the rate of coastline retreat. On Muostakh Island in the central Laptev Sea, East Siberia, changes in annual coastline position have been measured for decades and vary highly spatially. We hypothesize that these rates are inversely related to the inclination of the upper surface of submarine ice-bonded permafrost (IBP) based on the consequent duration of inundation with increasing distance from the shoreline. We compared rapidly eroding and stable coastal sections of Muostakh Island and find permafrost-table inclinations, determined using direct current resistivity, of 1 and 5 %, respectively. Determinations of submarine IBP depth from a drilling transect in the early 1980s were compared to resistivity profiles from 2011. Based on borehole observations, the thickness of unfrozen sediment overlying the IBP increased from 0 to 14 m below sea level with increasing distance from the shoreline. The geoelectrical profiles showed thickening of the unfrozen sediment overlying ice-bonded permafrost over the 28 years since drilling took place. We use geoelectrical estimates of IBP depth to estimate permafrost degradation rates since inundation. Degradation rates decreased from over 0.4 m a−1 following inundation to around 0.1 m a−1 at the latest after 60 to 110 years and remained constant at this level as the duration of inundation increased to 250 years. We suggest that long-term rates are lower than these values, as the depth to the IBP increases and thermal and porewater solute concentration gradients over depth decrease. For the study region, recent increases in coastal erosion rate and changes in benthic temperature and salinity regimes are expected to affect the depth to submarine permafrost, leading to coastal regions with shallower IBP.

scholarly journals Short and long-term thermo-erosion of ice-rich permafrost coasts in the Laptev Sea region

2013 ◽  
Vol 10 (2) ◽  
pp. 2705-2765 ◽  
Author(s):  
F. Günther ◽  
P. P. Overduin ◽  
A. V. Sandakov ◽  
G. Grosse ◽  
M. N. Grigoriev
Keyword(s):  
Coastal Erosion ◽  
The Arctic ◽  
Laptev Sea ◽  
Erosion Rates ◽  
The Past ◽  
Mass Fluxes ◽  
Study Sites ◽  
The Laptev Sea ◽  
Ice Complex

Abstract. Permafrost coasts in the Arctic are susceptible to a variety of changing environmental factors all of which currently point to increasing coastal erosion rates and mass fluxes of sediment and carbon to the shallow arctic shelf seas. Rapid erosion along high yedoma coasts composed of Ice Complex permafrost deposits creates impressive coastal ice cliffs and inspired research for designing and implementing change detection studies for a long time, but continuous quantitative monitoring and a qualitative inventory of coastal thermo-erosion for large coastline segments is still lacking. Our goal is to use observations of thermo-erosion along the mainland coast of the Laptev Sea in eastern Siberia to understand how erosion rates depend on coastal geomorphology and the relative contributions of waterline and atmospheric drivers to coastal thermo-erosion over the past 4 decades and in the past few years. We compared multitemporal sets of orthorectified satellite imagery from 1965 to 2011 for three segments of coastline with a length of 73 to 95 km each and analyzed thermo-denudation (TD) along cliff top and thermo-abrasion (TA) along cliff bottom for two nested time periods: long-term rates (the past 39–43 yr) and short term rates (the past 1–3 yr). The Normalized Difference Thermo-erosion Index (NDTI) was used as a proxy that qualitatively describes the relative proportions of TD and TA. Mean annual erosion rates at all three sites were higher in recent years (−5.3 ± 1.31 m a−1) than over the long term mean (−2.2 ± 0.13 m a−1). The Mamontov Klyk coast exhibit primarily spatial variations of thermo-erosion, while intrasite-specific variations were strongest at the Buor Khaya coast, where slowest long-term rates around −0.5 ± 0.08 m a−1 were observed. The Oyogos Yar coast showed continuously rapid erosion up to −6.5 ± 0.19 m a−1. In general, variable characteristics of coastal thermo-erosion were observed not only between study sites and over time, but also within single coastal transects along the cliff profile. Varying intensities of cliff bottom and top retreat are leading to diverse qualities of coastal erosion that have different impacts on coastal mass fluxes. The different extents of Ice Complex permafrost degradation within our study sites turned out to influence not only the degree of coupling between TD and TA, and the magnitude of effectively eroded volumes, but also the quantity of organic carbon released to the shallow Laptev Sea from coastal erosion, which ranged on a long-term from 88 ± 21.0 to 800 ± 61.1 t per km coastline per year and will correspond to considerably higher amounts, if recently observed more rapid coastal erosion rates prove to be persistent.

scholarly journals Short- and long-term thermo-erosion of ice-rich permafrost coasts in the Laptev Sea region

2013 ◽  
Vol 10 (6) ◽  
pp. 4297-4318 ◽  
Author(s):  
F. Günther ◽  
P. P. Overduin ◽  
A. V. Sandakov ◽  
G. Grosse ◽  
M. N. Grigoriev
Keyword(s):  
Coastal Erosion ◽  
The Arctic ◽  
Laptev Sea ◽  
Erosion Rates ◽  
The Past ◽  
Mass Fluxes ◽  
Study Sites ◽  
The Laptev Sea ◽  
Ice Complex

Abstract. Permafrost coasts in the Arctic are susceptible to a variety of changing environmental factors all of which currently point to increasing coastal erosion rates and mass fluxes of sediment and carbon to the shallow arctic shelf seas. Rapid erosion along high yedoma coasts composed of Ice Complex permafrost deposits creates impressive coastal ice cliffs and inspired research for designing and implementing change detection studies for a long time, but continuous quantitative monitoring and a qualitative inventory of coastal thermo-erosion for large coastline segments is still lacking. Our goal is to use observations of thermo-erosion along the mainland coast of the Laptev Sea, in eastern Siberia, to understand how it depends on coastal geomorphology and the relative contributions of water level and atmospheric drivers. We compared multi-temporal sets of orthorectified satellite imagery from 1965 to 2011 for three segments of coastline ranging in length from 73 to 95 km and analyzed thermo-denudation (TD) along the cliff top and thermo-abrasion (TA) along the cliff bottom for two nested time periods: long-term rates (the past 39–43 yr) and short-term rates (the past 1–4 yr). The Normalized Difference Thermo-erosion Index (NDTI) was used as a proxy to qualitatively describe the relative proportions of TD and TA. Mean annual erosion rates at all three sites were higher in recent years (−5.3 ± 1.3 m a−1) than over the long-term mean (−2.2 ± 0.1 m a−1). The Mamontov Klyk coast exhibits primarily spatial variations of thermo-erosion, while intrasite-specific variations caused by local relief were strongest at the Buor Khaya coast, where the slowest long-term rates of around −0.5 ± 0.1 m a−1 were observed. The Oyogos Yar coast showed continuously rapid erosion up to −6.5 ± 0.2 m a−1. In general, variable characteristics of coastal thermo-erosion were observed not only between study sites and over time, but also within single coastal transects along the cliff profile. Varying intensities of cliff bottom and top erosion are leading to diverse qualities of coastal erosion that have different impacts on coastal mass fluxes. The different extents of Ice Complex permafrost degradation within our study sites turned out to influence not only the degree of coupling between TD and TA, and the magnitude of effectively eroded volumes, but also the quantity of organic carbon released to the shallow Laptev Sea from coastal erosion, which ranged on a long-term from 88 ± 21 to 800 ± 61 t per km coastline per year and will correspond to considerably higher amounts, if recently observed more rapid coastal erosion rates prove to be persistent.

scholarly journals Coastal Erosion Variability at the Southern Laptev Sea Linked to Winter Sea Ice and the Arctic Oscillation

2020 ◽  
Vol 47 (5) ◽  
Author(s):  
David Marcolino Nielsen ◽  
Mikhail Dobrynin ◽  
Johanna Baehr ◽  
Sergey Razumov ◽  
Mikhail Grigoriev
Keyword(s):  
Sea Ice ◽  
Coastal Erosion ◽  
Arctic Oscillation ◽  
The Arctic ◽  
Laptev Sea ◽  
The Arctic Oscillation

scholarly journals Rapid retreat of permafrost coastline observed with aerial drone photogrammetry

2019 ◽  
Vol 13 (5) ◽  
pp. 1513-1528 ◽  
Author(s):  
Andrew M. Cunliffe ◽  
George Tanski ◽  
Boris Radosavljevic ◽  
William F. Palmer ◽  
Torsten Sachs ◽  
...  
Keyword(s):  
Coastal Erosion ◽  
Average Rate ◽  
Temporal Frequency ◽  
Shoreline Change ◽  
Yukon Territory ◽  
Aerial Photographs ◽  
The Arctic ◽  
Storm Events ◽  
Short Term

Abstract. Permafrost landscapes are changing around the Arctic in response to climate warming, with coastal erosion being one of the most prominent and hazardous features. Using drone platforms, satellite images, and historic aerial photographs, we observed the rapid retreat of a permafrost coastline on Qikiqtaruk – Herschel Island, Yukon Territory, in the Canadian Beaufort Sea. This coastline is adjacent to a gravel spit accommodating several culturally significant sites and is the logistical base for the Qikiqtaruk – Herschel Island Territorial Park operations. In this study we sought to (i) assess short-term coastal erosion dynamics over fine temporal resolution, (ii) evaluate short-term shoreline change in the context of long-term observations, and (iii) demonstrate the potential of low-cost lightweight unmanned aerial vehicles (“drones”) to inform coastline studies and management decisions. We resurveyed a 500 m permafrost coastal reach at high temporal frequency (seven surveys over 40 d in 2017). Intra-seasonal shoreline changes were related to meteorological and oceanographic variables to understand controls on intra-seasonal erosion patterns. To put our short-term observations into historical context, we combined our analysis of shoreline positions in 2016 and 2017 with historical observations from 1952, 1970, 2000, and 2011. In just the summer of 2017, we observed coastal retreat of 14.5 m, more than 6 times faster than the long-term average rate of 2.2±0.1 m a−1 (1952–2017). Coastline retreat rates exceeded 1.0±0.1 m d−1 over a single 4 d period. Over 40 d, we estimated removal of ca. 0.96 m3 m−1 d−1. These findings highlight the episodic nature of shoreline change and the important role of storm events, which are poorly understood along permafrost coastlines. We found drone surveys combined with image-based modelling yield fine spatial resolution and accurately geolocated observations that are highly suitable to observe intra-seasonal erosion dynamics in rapidly changing Arctic landscapes.

Rising Seas and Retreating Coasts: Implications for the Arctic

2020 ◽  
Vol 35 (3) ◽  
pp. 468-497
Author(s):  
Clive Schofield ◽  
Suzanne Lalonde
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Coastal Erosion ◽  
Legal Issues ◽  
The Arctic ◽  
Future Challenge ◽  
Legal Regime ◽  
Legal Responses ◽  
Key Aspects ◽  
Impacts Of Climate Change

Abstract This article addresses both the physical impacts and international legal issues arising from two interlinked stressors on Arctic coastlines: sea level rise and coastal erosion. Key aspects of the legal regime governing the baselines from which coastal States calculate the outer limits of their maritime zones are reviewed and a synopsis of the practice among the Arctic littoral States is provided. The article then turns to a discussion of the practical and international legal responses available to deal with the present and future challenge of rising seas and retreating coasts. The concluding section offers with some reflections on the way forward for a region experiencing some of the most devastating impacts of climate change.

scholarly journals Long-term variability of dust events in Iceland (1949–2011)

2014 ◽  
Vol 14 (11) ◽  
pp. 17331-17358 ◽  
Author(s):  
P. Dagsson-Waldhauserova ◽  
O. Arnalds ◽  
H. Olafsson
Keyword(s):  
Sea Level ◽  
Dust Storms ◽  
The Arctic ◽  
Atmospheric Dust ◽  
Sea Level Pressure ◽  
Term Frequency ◽  
The World ◽  
Dust Events ◽  
The 1960S

Abstract. Long-term frequency of atmospheric dust observations was investigated for the southern part of Iceland and merged with results obtained from the Northeast Iceland (Dagsson-Waldhauserova et al., 2013). In total, over 34 dust days per year on average occurred in Iceland based on conventionally used synoptic codes for dust. Including codes 04–06 into the criteria for dust observations, the frequency was 135 dust days annually. The Sea Level Pressure (SLP) oscillation controlled whether dust events occurred in NE (16.4 dust days annually) or in southern part of Iceland (about 18 dust days annually). The most dust-frequent decade in S Iceland was the 1960s while the most frequent decade in NE Iceland was the 2000s. A total of 32 severe dust storms (visibility < 500 m) was observed in Iceland with the highest frequency during the 2000s in S Iceland. The Arctic dust events (NE Iceland) were typically warm and during summer/autumn (May–September) while the Sub-Arctic dust events (S Iceland) were mainly cold and during winter/spring (March–May). About half of dust events in S Iceland occurred in winter or at sub-zero temperatures. A good correlation was found between PM10 concentrations and visibility during dust observations at the stations Vik and Storhofdi. This study shows that Iceland is among the dustiest areas of the world and dust is emitted the year-round.

scholarly journals IMMERSIVE EXPERIENCES IN CLIMATE ADAPTATION

2020 ◽  
pp. 10
Author(s):  
Juliano Calil
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Erosion ◽  
Climate Adaptation ◽  
3D Models ◽  
Coastal Communities ◽  
Long Beach ◽  
Coastal Risks ◽  
Impacts Of Climate Change

As coastal communities worldwide contend with sea-level rise, coastal erosion, and other impacts of climate change, a critical piece of the puzzle has become educating stakeholders in highly creative, insightful, and practical ways. In this study, we will highlight the main findings from the use of immersive and interactive Virtual Reality (VR) experiences in climate adaptation. These tools are helping coastal communities better understand potential impacts as well as explore near- and long-term solutions to reduce coastal risks. We will describe the challenges and steps taken to develop these applications at four coastal locations in the U.S. (Turner Station, MD, and Santa Cruz, Long Beach, and Moss Landing in CA); from identifying key objectives of each experience, the critical messages, and target audiences, to flying drones over coastal areas and working with photogrammetry to create hyper-realistic 3D models that are inserted in the VR experience. These immersive and interactive experiences support planning, management and monitoring activities related to sea-level rise, storms, coastal erosion, king tides, and more. These tools are being developed by a multidisciplinary team with a range of expertise including climate and coastal scientists, city planners, communications experts, filmmakers, 3D animators, and VR developers.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/aDIkbn_FO1c

Tendencies of multi-year variability of the sea level at the coastal stations of the Аrctic оcean

2017 ◽  
pp. 51-66
Author(s):  
V. A. Merkulov ◽  
I. M. Ashik ◽  
L. А. Timokhov
Keyword(s):  
Sea Level ◽  
Climatic Conditions ◽  
The Arctic ◽  
Arctic Seas ◽  
Annual Average ◽  
Sea Level Fluctuations ◽  
Almost All ◽  
Freshwater River ◽  
Linear Trends

New estimates of linear trends in the position of the level surface were obtained as a result of analysis of the data of long-term observations of sea level fluctuations at the stations of the seas of the Arctic Ocean. A rise in sea level is observed at almost all stations. In multi-year fluctuations of the level, periods characterized by different values of linear trends are identified. The reasons for the variability of local linear trends in the level of the Arctic seas from the 1950-1980 stage to the 1990-2015 period are analyzed. It is shown that the presence of local trends during the annual average levels at coast stations is a consequence of changes in climatic conditions reflected in changes in atmospheric and hydrosphere climatic indices, as well as in freshwater river runoff.

scholarly journals A Probabilistic Model of Coastal Bluff-Top Erosion in High Latitudes Due to Thermoabrasion: A Case Study from Baydaratskaya Bay in the Kara Sea

2020 ◽  
Vol 8 (3) ◽  
pp. 169
Author(s):  
Mohammad Akhsanul Islam ◽  
Raed Lubbad ◽  
Mohammad Saud Afzal
Keyword(s):  
Sea Level ◽  
Probabilistic Model ◽  
Coastal Erosion ◽  
Global Climate ◽  
High Sensitivity ◽  
Kara Sea ◽  
The Arctic ◽  
Field Observations ◽  
Sea Level Changes ◽  
Erosion Mechanisms

Arctic coastal erosion demands more attention as the global climate continues to change. Unlike those along low-latitude and mid-latitude, sediments along Arctic coastlines are often frozen, even during summer. Thermal and mechanical factors must be considered together when analysing Arctic coastal erosion. Two major erosion mechanisms in the Arctic have been identified: thermodenudation and thermoabrasion. Field observations of Arctic coastal erosion are available in Baydaratskaya Bay in the Kara Sea. The objective of this study is to develop a probabilistic model of thermoabrasion to simulate the measured coastal erosion at two sites where observations suggest thermoabrasion is dominant. The model simulates two time periods: (a) the summer of 2013 (2012–2013) and (b) the summer of 2017 (2016–2017). A probabilistic analysis is performed to quantify the uncertainties in the model results. The input parameters are assumed to follow normal and lognormal distributions with a 10% coefficient of variation. Monte Carlo simulation is applied to determine the erosion rates for the two different cases. The simulation results agree reasonably well with the field observations. In addition, a sensitivity analysis is performed, revealing a very high sensitivity of the model to sea-level changes. The model indicates that the relation between sea-level rise and thermoabrasional erosion is exponential.

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