Increasing coastal slump activity impacts the release of sediment and organic carbon into the Arctic Ocean

Ramage, Justine; Irrgang, Anna; Morgenstern, Anne; Lantuit, Hugues

doi:10.5194/bg-15-1483-2018

Cited by 31 publications

(33 citation statements)

References 63 publications

(94 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No disturbances in peat accumulation were indicated in low‐centered Ptarmigan Polygon (this study), nor in a low‐centered ice‐wedge polygon studied on Herschel Island, which showed undisturbed peat formation for the last 3000 years. The main Holocene and modern sources of disturbance on the Yukon Coastal Plain are mass wasting processes linked to increased coastal erosion and thermokarst as well as thermal erosion . The question of whether disturbance triggered later drainage of the polygon centers and finally led to relief inversion cannot be answered at this stage, but will be worth investigating.…”

Section: Discussionmentioning

confidence: 99%

“…The main Holocene and modern sources of disturbance on the Yukon Coastal Plain are mass wasting processes 86,87 linked to increased coastal erosion 88 and thermokarst 64 as well as thermal erosion. 89 The question of whether disturbance triggered later drainage of the polygon centers and finally led to relief inversion cannot be answered at this stage, but will be worth investigating.…”

Section: Climate Vs Geomorphic Disturbances As Drivers Of Change Imentioning

confidence: 99%

See 1 more Smart Citation

Climatic, geomorphologic and hydrologic perturbations as drivers for mid‐ to late Holocene development of ice‐wedge polygons in the western Canadian Arctic

Wolter

Lantuit

Wetterich

et al. 2018

Permafrost & Periglacial

Self Cite

View full text Add to dashboard Cite

Ice‐wedge polygons are widespread periglacial features and influence landscape hydrology and carbon storage. The influence of climate and topography on polygon development is not entirely clear, however, giving high uncertainties to projections of permafrost development. We studied the mid‐ to late Holocene development of modern ice‐wedge polygon sites to explore drivers of change and reasons for long‐term stability. We analyzed organic carbon, total nitrogen, stable carbon isotopes, grain size composition and plant macrofossils in six cores from three polygons. We found that all sites developed from aquatic to wetland conditions. In the mid‐Holocene, shallow lakes and partly submerged ice‐wedge polygons existed at the studied sites. An erosional hiatus of ca 5000 years followed, and ice‐wedge polygons re‐initiated within the last millennium. Ice‐wedge melt and surface drying during the last century were linked to climatic warming. The influence of climate on ice‐wedge polygon development was outweighed by geomorphology during most of the late Holocene. Recent warming, however, caused ice‐wedge degradation at all sites. Our study showed that where waterlogged ground was maintained, low‐centered polygons persisted for millennia. Ice‐wedge melt and increased drainage through geomorphic disturbance, however, triggered conversion into high‐centered polygons and may lead to self‐enhancing degradation under continued warming.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Climate Vs Geomorphic Disturbances As Drivers Of Change Imentioning

confidence: 99%

Climatic, geomorphologic and hydrologic perturbations as drivers for mid‐ to late Holocene development of ice‐wedge polygons in the western Canadian Arctic

Wolter

Lantuit

Wetterich

et al. 2018

Permafrost & Periglacial

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thawing permafrost and deepening of the active layer lead to the mobilization of this carbon (Osterkamp, 2007;Woo et al, 2008), the release of carbon dioxide (CO 2 ) and methane (CH 4 ) to the atmosphere (Schaefer et al, 2014), and an increase in riverine dissolved organic carbon (DOC) fluxes (Frey and Smith, 2005;Le Fouest et al, 2018). Also associated with warming is the development of surface (physical) disturbances such as active layer detachments or retrogressive thaw slumps (Lacelle et al, 2010;Lamoureux and Lafrenière, 2009;Lewkowicz, 2007;Ramage et al, 2018) and thermal perturbation of the subsurface (Lafrenière and Lamoureux, 2013). As these processes influence freshwater systems, they ultimately have impacts on the biological production and the biogeochemistry of the Arctic Ocean.…”

Section: Introductionmentioning

confidence: 99%

Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments

Coch

Juhls²,

Lamoureux

et al. 2019

Biogeosciences

Self Cite

View full text Add to dashboard Cite

Abstract. Climate change is affecting the rate of carbon cycling, particularly in the Arctic. Permafrost degradation through deeper thaw and physical disturbances results in the release of carbon dioxide and methane to the atmosphere and to an increase in lateral dissolved organic matter (DOM) fluxes. Whereas riverine DOM fluxes of the large Arctic rivers are well assessed, knowledge is limited with regard to small catchments that cover more than 40 % of the Arctic drainage basin. Here, we use absorption measurements to characterize changes in DOM quantity and quality in a low Arctic (Herschel Island, Yukon, Canada) and a high Arctic (Cape Bounty, Melville Island, Nunavut, Canada) setting with regard to geographical differences, impacts of permafrost degradation, and rainfall events. We find that DOM quantity and quality is controlled by differences in vegetation cover and soil organic carbon content (SOCC). The low Arctic site has higher SOCC and greater abundance of plant material resulting in higher chromophoric dissolved organic matter (cDOM) and dissolved organic carbon (DOC) than in the high Arctic. DOC concentration and cDOM in surface waters at both sites show strong linear relationships similar to the one for the great Arctic rivers. We used the optical characteristics of DOM such as cDOM absorption, specific ultraviolet absorbance (SUVA), ultraviolet (UV) spectral slopes (S275–295), and slope ratio (SR) for assessing quality changes downstream, at base flow and storm flow conditions, and in relation to permafrost disturbance. DOM in streams at both sites demonstrated optical signatures indicative of photodegradation downstream processes, even over short distances of 2000 m. Flow pathways and the connected hydrological residence time control DOM quality. Deeper flow pathways allow the export of permafrost-derived DOM (i.e. from deeper in the active layer), whereas shallow pathways with shorter residence times lead to the export of fresh surface- and near-surface-derived DOM. Compared to the large Arctic rivers, DOM quality exported from the small catchments studied here is much fresher and therefore prone to degradation. Assessing optical properties of DOM and linking them to catchment properties will be a useful tool for understanding changing DOM fluxes and quality at a pan-Arctic scale.

show abstract

“…Erosional processes in the permafrost coast result in release of large amounts of sediment and organic matter to the nearshore zone . For example, the mean annual rates of sediment release due to coastal erosion are estimated to range between 800 and 5400 m 3 /km/yr (m 3 per km coastline per year) in the Barents, Kara, Laptev, East Siberian and Russian Chukchi Seas (e.g., ).…”

Section: Discussionmentioning

confidence: 99%

Cliff retreat of permafrost coast in south‐west Baydaratskaya Bay, Kara Sea, during 2005–2016

Исаев

Koshurnikov

Pogorelov

et al. 2019

Permafrost & Periglacial

View full text Add to dashboard Cite

Recent years of increasing air temperature in the Arctic have led to a significant increase in the rate of retreat of permafrost coast, which has threatened livelihoods and infrastructure in these areas. The Kara Sea hosts more than 25% of the total Arctic coastline. However, little is known about how coastal erosion in the Kara Sea may have changed through time, and the climatic and environmental drivers remain unclear. Here we study coastal dynamics along a 4-km stretch of permafrost and sea-ice-affected coastline in south-west Baydaratskaya Bay of the Kara Sea, western Siberia, between 2005 and 2016, by using handheld differential GPS mapping and satellite imagery.We identified temporal and spatial variations in the retreat rates, ranging between 1.0 (+0.1/−0.6) and 1.9 (+0.7/−1.3) m/yr over the studied coastline during 2005-2016. We also made ground temperature measurements, subsurface resistivity measurements and estimates of wave energy flux of wind-driven ocean waves, to investigate the dominant climatic factors influencing the observed retreat rates through time. We found that wind-driven wave activity during sea-ice-free days influences the magnitude of coastal retreat in the study area, while recent temperature rise has contributed less to enhancing coastal retreat during the study period. This suggests that the amount of eroded sediment and the associated release of nutrient to the nearshore zone are controlled by the magnitude of wave activity, which may influence infrastructure along the permafrost coast and marine ecosystems in the proximal ocean.

show abstract

Increasing coastal slump activity impacts the release of sediment and organic carbon into the Arctic Ocean

Cited by 31 publications

References 63 publications

Climatic, geomorphologic and hydrologic perturbations as drivers for mid‐ to late Holocene development of ice‐wedge polygons in the western Canadian Arctic

Climatic, geomorphologic and hydrologic perturbations as drivers for mid‐ to late Holocene development of ice‐wedge polygons in the western Canadian Arctic

Comparisons of dissolved organic matter and its optical characteristics in small low and high Arctic catchments

Cliff retreat of permafrost coast in south‐west Baydaratskaya Bay, Kara Sea, during 2005–2016

Contact Info

Product

Resources

About