scholarly journals The Seasonal Evolution of Subglacial Drainage Pathways Beneath a Soft-bedded Glacier

2021 ◽  
Author(s):  
Jane K. Hart ◽  
David S. Young ◽  
Nathaniel R. Baurley ◽  
Benjamin A. Robson ◽  
Kirk Martinez
Keyword(s):  
Climate Change ◽  
Sediment Layer ◽  
Seasonal Evolution ◽  
Rapid Access ◽  
Speed Up ◽  
Self Organizing ◽  
Subglacial Drainage

Abstract Subglacial hydrology is a key element in glacier response to climate change, but investigations of this environment are logistically difficult. Most models are based on summer data from glaciers resting on rigid bedrocks. However a significant number of glaciers rest on soft (unconsolidated sedimentary) beds. Here we present a unique multi-year instrumented record of the development of seasonal subglacial behavior associated with an Icelandic temperate glacier resting on a deformable sediment layer. We observe a distinct annual pattern in the subglacial hydrology based on self-organizing anastomosing braided channels. Water is stored within the subglacial system itself (till, braided system and ‘ponds’), allowing the rapid access of water to enable glacier speed-up events to occur throughout the year, particularly in winter.

scholarly journals The Seasonal Evolution of Subglacial Drainage Pathways Beneath a Soft-bedded Glacier

2021 ◽  
Author(s):  
Jane Hart ◽  
David Young ◽  
Nathaniel Baurley ◽  
Benjamin Robson ◽  
Kirk Martinez
Keyword(s):  
Climate Change ◽  
Sediment Layer ◽  
West Antarctica ◽  
Ice Streams ◽  
Seasonal Evolution ◽  
Rapid Access ◽  
Speed Up ◽  
Self Organizing ◽  
Subglacial Drainage

Abstract Subglacial hydrology is a key element in glacier response to climate change, but investigations of this environment are logistically difficult. Most models are based on summer data from glaciers resting on rigid bedrocks. However a significant number of glaciers rest on soft (unconsolidated sedimentary) beds, including the potentially unstable ice streams of West Antarctica. Here we present a rare multi-year instrumented record of the development of seasonal subglacial behavior in a temperate glacier resting on a deformable sediment layer as an analogue for West Antarctica. We observe a distinct annual pattern in the subglacial hydrology based on self-organizing anastomosing braided channels. Water is stored within the subglacial system itself (till, braided system and ‘ponds’), allowing the rapid access of water to enable glacier speed-up events to occur throughout the year, particularly in winter.

The Changing Ethics of Climate Change

2014 ◽  
Vol 28 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Daniel Mittler
Keyword(s):  
Climate Change ◽  
Power Plant ◽  
Moral Obligation ◽  
Environmental Movement ◽  
Health Problems ◽  
Renewable Energies ◽  
Car Use ◽  
The Face ◽  
Speed Up ◽  
The Right

Many in the environmental movement have argued in recent years that in order to speed up climate actions we should take the ethics out of the climate change debate. Focusing on the moral obligation to act or on the effects of climate change on the most vulnerable was often judged to render the discourse too “heavy,” “negative,” or “difficult.” Many also deemed it unnecessary. After all, renewable energies, better designed cities that allow for reduced car use, and power plant regulations that lead to cleaner local air—to take just three examples—all have real and substantial benefits unrelated to the fact that they are “the right thing to do” in the face of climate change. They create jobs, reduce health problems and costs, and make society fitter.

scholarly journals Machine Learning Speeding Up the Development of Portfolio of New Crop Varieties to Adapt to and Mitigate Climate Change

2021 ◽  
Author(s):  
Abdallah Bari ◽  
Hassan Ouabbou ◽  
abderrazek Jilal ◽  
Hamid Khazaei ◽  
Fred Stoddard ◽  
...  
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Crop Varieties ◽  
Short Period ◽  
Speed Up ◽  
Increasing Demand ◽  
Mitigate Climate Change ◽  
High Yielding Varieties ◽  
New Crop ◽  
Adaptation And Mitigation

Climate change poses serious challenges to achieving food security in a time of a need to produce more food to keep up with the worlds increasing demand for food. There is an urgent need to speed up the development of new high yielding varieties with traits of adaptation and mitigation to climate change. Mathematical approaches, including ML approaches, have been used to search for such traits, leading to unprecedented results as some of the traits, including heat traits that have been long sought-for, have been found within a short period of time.

scholarly journals How to Manage the Cop21 Policies?

2018 ◽  
Vol 9 (4) ◽  
pp. 1
Author(s):  
Jan-Erik Lane
Keyword(s):  
Social Sciences ◽  
Climate Change ◽  
Global Warming ◽  
Positive Feedback ◽  
Abrupt Climate Change ◽  
Overwhelming Evidence ◽  
The Social ◽  
Management Plans ◽  
Speed Up ◽  
To Come

While the climate and earth scientists now launch the new theory of abrupt climate change with overwhelming evidence about CO2s and the positive feedback lopes from Arctic meltdown and methane emissions from permafrost, the UNFCCC does not speed up the implementation of its promised policies. The social sciences have yet to come up with management plans for global decarbonisation. Resilience is no longer an option when the tipping point is muck closer in time than earlier believed. The key nations are not taking steps towards the saving of mankind from run away global warming.

scholarly journals Modeling the response of subglacial drainage at Paakitsoq, west Greenland, to 21stcentury climate change

2014 ◽  
Vol 119 (12) ◽  
pp. 2619-2634 ◽  
Author(s):  
Jerome R. Mayaud ◽  
Alison F. Banwell ◽  
Neil S. Arnold ◽  
Ian C. Willis
Keyword(s):  
Climate Change ◽  
West Greenland ◽  
Subglacial Drainage

Application of self-organizing maps technique in downscaling GCMs climate change projections for Same, Tanzania

2010 ◽  
Vol 35 (13-14) ◽  
pp. 608-617 ◽  
Author(s):  
S.D. Tumbo ◽  
E. Mpeta ◽  
M. Tadross ◽  
F.C. Kahimba ◽  
B.P. Mbillinyi ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Change Projections ◽  
Self Organizing Maps ◽  
Self Organizing

Melt-induced speed-up of Greenland ice sheet offset by efficient subglacial drainage

Nature ◽  
2011 ◽  
Vol 469 (7331) ◽  
pp. 521-524 ◽  
Author(s):  
Aud Venke Sundal ◽  
Andrew Shepherd ◽  
Peter Nienow ◽  
Edward Hanna ◽  
Steven Palmer ◽  
...  
Keyword(s):  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Speed Up ◽  
Subglacial Drainage

scholarly journals High-resolution modelling of the seasonal evolution of surface water storage on the Greenland Ice Sheet

2013 ◽  
Vol 7 (6) ◽  
pp. 6143-6170 ◽  
Author(s):  
N. S. Arnold ◽  
A. F. Banwell ◽  
I. C. Willis
Keyword(s):  
Surface Water ◽  
High Resolution ◽  
Water Storage ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Water Volume ◽  
Seasonal Evolution ◽  
Surface Water Storage ◽  
Subglacial Drainage

Abstract. Seasonal meltwater lakes on the Greenland Ice Sheet form when surface runoff is temporarily trapped in surface topographic depressions. The development of such lakes affects both the surface energy balance and dynamics of the ice sheet. Although areal extents, depths, and lifespans of lakes can be inferred from satellite imagery, such observational studies have a limited temporal resolution. Here, we adopt a modelling-based strategy to estimate the seasonal evolution of surface water storage for the ~ 3600 km2 Paakitsoq region of W. Greenland. We use a high-resolution time dependent surface mass balance model to calculate surface melt, a supraglacial water routing model to calculate lake filling and a prescribed water-volume based threshold to predict lake drainage events. The model shows good agreement between modelled lake locations and volumes and those observed in 9 Landsat 7 ETM+ images from 2001, 2002 and 2005. We use the model to investigate the lake water volume required to trigger drainage, and the impact that this threshold volume has on the proportion of meltwater that runs off the ice supraglacially, is stored in surface lakes, or enters the subglacial drainage system. Model performance is maximised with prescribed lake volume thresholds between 4000 and 7500 times the local ice thickness. For these thresholds, lakes transiently store < 40% of meltwater at the beginning of the melt season, decreasing to ~ 5 to 10% by the middle of the melt season. 40 to 50% of meltwater runs off the ice surface directly, and the remainder enters the subglacial drainage system through moulins at the bottom of drained lakes.

scholarly journals Can We Have Our Cake and Eat It? A Review of the Debate on Green Recovery from the COVID-19 Crisis

2021 ◽  
Vol 13 (2) ◽  
pp. 874 ◽  
Author(s):  
Ema Gusheva ◽  
Vincent de Gooyert
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
The Netherlands ◽  
Gross Domestic Product ◽  
Greenhouse Gas ◽  
Systems Thinking ◽  
Economic Downturn ◽  
Sustainability Transition ◽  
Key Concepts ◽  
Speed Up

As we speed through the development and distribution of a vaccine for the COVID-19 pandemic, economies are suffering through the worst decline of the century while, at the same time, being pushed to comply with global agreements regarding climate change. Because of this, the economic downturn is also seen as an opportunity to speed up the sustainability transition or, in simple terms, to achieve a “green recovery”. What can we expect from a green recovery? We address this question by reviewing position documents in the debate between green recovery and its opponent, “quick rebound”, in the Netherlands. We apply systems thinking to model causal arguments regarding key concepts comprising green recovery and identify issues of consensus and dissensus. Our findings indicate that green recovery is promising for curbing greenhouse gas emissions and addressing growing socioeconomic inequalities. However, the position of what green recovery means for economic growth, including the development of gross domestic product and employment, is still largely unclear and at times contradictory. While some see tradeoffs, others suggest that economic growth and sustainability goals can be achieved simultaneously. Thus, we conclude by reflecting on the question: Can we have our cake and eat it?

scholarly journals Tidewater calving

1996 ◽  
Vol 42 (141) ◽  
pp. 375-385 ◽  
Author(s):  
С.J. Van Der Veen
Keyword(s):  
Water Depth ◽  
Fold Increase ◽  
Actual Rate ◽  
Tidewater Glaciers ◽  
Glacier Terminus ◽  
Tidewater Glacier ◽  
Iceberg Calving ◽  
Speed Up ◽  
Calving Rate ◽  
Subglacial Drainage

AbstractData from Columbia Glacier are used to identify processes that control calving from a temperate tidewater glacier and to re-evaluate models that have been proposed to describe iceberg calving. Since 1981, Columbia Glacier has been retreating rapidly, with an almost seven-fold increase in calving rate from the mid-1970s to 1993. At the same time, the speed of the glacier increased almost as much, so that the actual rate of retreat increased more slowly. According to the commonly accepted model, the calving rate is linearly related to the water depth at the terminus, with retreat of the glacier snout into deeper water, leading to larger calving rates and accelerated retreat. The Columbia Glacier data show that the calving rate is not simply linked to observed quantities such as water depth or stretching rate near the terminus. During the retreat, the thickness at the terminus appears to be linearly correlated with the water depth; at the terminus, the thickness in excess of flotation remained at about 50 m. This suggests that retreat may be initiated when the terminal thickness becomes too small, with the rate of retreat controlled by the rate at which the snout is thinning and by the basal slope. The implication is that the rapid retreat of Columbia Glacier (and other comparable tidewater glaciers) is not the result of an increase in calving as the glacier retreated into deeper water. Instead, the retreat was initiated and maintained by thinning of the glacier. For Columbia Glacier, the continued thinning is probably associated with the increase in glacier speed and retreat may be expected to continue as long as these large speeds are maintained. It is not clear what mechanism may be responsible for the speed-up but the most likely candidate is a change in basal conditions or subglacial drainage. Consequently, the behavior of tidewater glaciers may be controlled by processes acting at the glacier bed rather than by what happens at the glacier terminus.

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