34 research outputs found

    Climate change and the global pattern of moraine-dammed glacial lake outburst floods

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    This is the author accepted manuscript. The final version is available from EGU via the DOI in this recordThe published version, as published in The Cryosphere, is in ORE: http://hdl.handle.net/10871/32433Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste and many have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the collapse of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and their regularity – rather unexpectedly – has declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century.SH was funded by a Leverhulme Research Fellowship. SH, RAB and AW acknowledge funding under the HELIX (European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° 603864). AW and RAB acknowledge funding from the Joint UK DECC/Defra Met Office Hadley Centre Climate Programme (GA01101)

    Climate Change and the Global Pattern of Moraine-Dammed Glacial Lake Outburst Floods

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    Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste. GLOFs can have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the rapid drainage of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and regularity – rather unexpectedly – have declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From an assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine-dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century

    Climate change and the global pattern of moraine-dammed glacial lake outburst floods

    Get PDF
    This is the author accepted manuscript. The final version is available from EGU via the DOI in this recordThe published version, as published in The Cryosphere, is in ORE: http://hdl.handle.net/10871/32433Despite recent research identifying a clear anthropogenic impact on glacier recession, the effect of recent climate change on glacier-related hazards is at present unclear. Here we present the first global spatio-temporal assessment of glacial lake outburst floods (GLOFs) focusing explicitly on lake drainage following moraine dam failure. These floods occur as mountain glaciers recede and downwaste and many have an enormous impact on downstream communities and infrastructure. Our assessment of GLOFs associated with the collapse of moraine-dammed lakes provides insights into the historical trends of GLOFs and their distributions under current and future global climate change. We observe a clear global increase in GLOF frequency and their regularity around 1930, which likely represents a lagged response to post-Little Ice Age warming. Notably, we also show that GLOF frequency and their regularity – rather unexpectedly – has declined in recent decades even during a time of rapid glacier recession. Although previous studies have suggested that GLOFs will increase in response to climate warming and glacier recession, our global results demonstrate that this has not yet clearly happened. From assessment of the timing of climate forcing, lag times in glacier recession, lake formation and moraine dam failure, we predict increased GLOF frequencies during the next decades and into the 22nd century.SH was funded by a Leverhulme Research Fellowship. SH, RAB and AW acknowledge funding under the HELIX (European Union Seventh Framework Programme FP7/2007-2013 under grant agreement n° 603864). AW and RAB acknowledge funding from the Joint UK DECC/Defra Met Office Hadley Centre Climate Programme (GA01101)

    Glacial Lake Outburst Flood in the Chuchún Watershed, Cordillera Blanca, Peru

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    Glacial Lake Outburst Floods (GLOFs) Database Project

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    Stochastic assessment of landslides and debris flows in the Jemma basin, Blue Nile, Central Ethiopia

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    In this paper we evaluate a stochastic method to assess the spatial distribution of landslide and debris flow processes in the Jemma basin, Central Ethiopia. The Jemma basin is draining the highlands (max. 3.676 m a.s.l.) northeast of Addis Ababa towards the Blue Nile. The basin is characterized by a deeply incised stratigraphy made up of volcanic deposits like flood basalts and tephra. Hence, gravitational mass movements as well as water driven erosion processes occur, documented by the respective forms. We mapped these features using Google Earth images, aerial photo interpretation and fieldwork. The information about the spatial distribution of landslide and debris flow forms was taken as dependent variable in the stochastic modelling approach. Moreover, we performed a detailed terrain analysis to derive the independent variables. We applied two different stochastic modelling approaches based on i) Boosted Regression Trees (BRT) and ii) on an Maximum Entropy Method (MEM) to predict the potential spatial distribution of landslides and debris flows in the Jemma basin. The models are statistically evaluated using the training data and a set of performance parameters such as the area under the receiver operating characteristic curve (AUC). Variable importance and response curves provide further insight into controlling factors of landslide and debris flow distribution. The study shows that both processes can be perfectly identified and distinguished. The spatial distribution of the predicted process susceptibilities generally follows topographic constraints. Model performance parameters show better results for BRT, that outperforms MEM. However, MEM results are quite robust and hence are used for the spatial prediction of process susceptibilities
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