scholarly journals Warming of SE Greenland shelf waters in 2016 primes large glacier for runaway retreat

2019 ◽  
Author(s):  
Suzanne L. Bevan ◽  
Adrian J. Luckman ◽  
Douglas I. Benn ◽  
Tom Cowton ◽  
Joe Todd
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Continental Shelf ◽  
East Greenland ◽  
The Past ◽  
Warm Surface Water

Abstract. Kangerdluqssuaq Glacier in south-east Greenland has now retreated further inland than at any time in the past 33 years and is fast approaching a region of retrograde bedslope, meaning that continued rapid retreat is likely. Here we show that the current retreat was driven by anomalously warm surface water on the continental shelf during 2016. The warm surface water likely penetrated the fjord and weakened the mixture of sea ice and icebergs known as mélange, which is normally rigid enough to inhibit calving in winter. As Kangerdlugssuaq Glacier continued to calve almost continuously throughout 2017 and 2018 it accelerated by 35 % and thinned by 35 m.

scholarly journals Impact of warming shelf waters on ice mélange and terminus retreat at a large SE Greenland glacier

2019 ◽  
Vol 13 (9) ◽  
pp. 2303-2315 ◽  
Author(s):  
Suzanne L. Bevan ◽  
Adrian J. Luckman ◽  
Douglas I. Benn ◽  
Tom Cowton ◽  
Joe Todd
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Continental Shelf ◽  
Deep Ocean ◽  
Near Surface ◽  
Surface Ocean ◽  
The Past ◽  
Tidewater Glacier ◽  
Warm Surface Water ◽  
Bed Slope

Abstract. By the end of 2018 Kangerlussuaq Glacier in southeast Greenland had retreated further inland than at any time in the past 80 years and its terminus was approaching a region of retrograde bed slope from where further rapid retreat would have been inevitable. Here we show that the retreat occurred because the glacier failed to advance during the winters of 2016/17 and 2017/18 owing to a weakened proglacial mélange. This mixture of sea ice and icebergs is normally rigid enough to inhibit calving in winter, but for 2 consecutive years it repeatedly collapsed, allowing Kangerlussuaq Glacier to continue to calve all year round. The mélange break-ups followed the establishment of anomalously warm surface water on the continental shelf during 2016, which likely penetrated the fjord. As calving continued uninterrupted from summer 2016 to the end of 2018 the glacier accelerated by 35 % and thinned by 35 m. These observations demonstrate the importance of near-surface ocean temperatures in tidewater glacier stability and show that it is not only deep-ocean warming that can lead to glacier retreat. During winter 2019 a persistent mélange reformed and the glacier readvanced by 3.5 km.

Decadal variance of summer near-surface temperature maximum in Canada Basin of Arctic Ocean

2020 ◽  
Author(s):  
Long Lin ◽  
Hailun He
Keyword(s):  
Surface Water ◽  
Sea Ice ◽  
Surface Temperature ◽  
Heat Content ◽  
Canada Basin ◽  
Previous Theory ◽  
Sea Ice Extent ◽  
Sea Ice Thickness ◽  
Near Surface ◽  
Warm Surface Water

<p>In the summer Arctic, bump-like vertical temperature profiles of the upper layer in the Canada Basin suggest a near-surface temperature maximum (NSTM) beneath the mixed layer. This paper concentrates on describing the decadal variance of these NSTMs. Essentially, the temporal evolution of the summer NSTM revealed three decadal phases. The first period is before 2003, when the summer NSTM could rarely be observed except around the marginal of the Canada Basin. The second period is between 2003 and 2015, when the summer NSTM nearly occurred over the whole basin as accelerated decline of summer sea ice. The third period is from 2016 to 2017, when the summer NSTM almost disappeared due to prevailing warm surface water. Furthermore, for the background behind the decadal variance of summer NSTM, linear trends of the September minimum sea ice extent and surface water heat content in the Canada Basin from 2003 to 2017 were –2.75±1.08×10<sup>4</sup>km<sup>2</sup>yr<sup>–1</sup> and 2.29±1.36MJ m<sup>–2</sup>yr<sup>–1</sup>, respectively. According to a previous theory, if we assume that the trend of the summer surface water heat content was only contributed by NSTM, it would cause a decrease in sea ice thickness of approximately 13 cm. The analysis partially explains the reason for sea ice decline in recent years.</p>

New insights on the north-eastern part of the Ketilidian orogen in South-East Greenland

1999 ◽  
pp. 23-33 ◽  
Author(s):  
Adam A. Garde ◽  
John Grocott ◽  
Ken J.W. McCaffrey
Keyword(s):  
Sea Ice ◽  
Coastal Areas ◽  
East Greenland ◽  
Original Series ◽  
The North ◽  
North Eastern ◽  
North Eastern Part ◽  
Geological Research

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Garde, A. A., Grocott, J., & McCaffrey, K. J. (1999). New insights on the north-eastern part of the Ketilidian orogen in South-East Greenland. Geology of Greenland Survey Bulletin, 183, 23-33. https://doi.org/10.34194/ggub.v183.5201 _______________ During a five week period in August–September 1998 the poorly known north-eastern part of the Palaeoproterozoic (c. 1800 Ma) Ketilidian orogen between Kangerluluk and Mogens Heinesen Fjord in South-East Greenland (Fig. 1) was investigated in continuation of recent geological research in other parts of the orogen. The north-eastern part of the orogen is remote from inhabited areas. It is mountainous and comprises a wide nunatak zone which can only be reached easily by helicopter. Furthermore, access to coastal areas by boat is difficult because many parts of the coast are prone to be ice-bound even during the summer months, due to wind- and current-driven movements of the sea ice.

The Vyredox and Nitredox Methods of in situ Treatment of Groundwater

1988 ◽  
Vol 20 (3) ◽  
pp. 149-163 ◽  
Author(s):  
Carol Braester ◽  
Rudolf Martinell
Keyword(s):  
Water Treatment ◽  
Surface Water ◽  
Traditional Method ◽  
Treatment Method ◽  
Nitrate Treatment ◽  
The Past ◽  
The World ◽  
Nitrate And Nitrite ◽  
Iron And Manganese

Nearly one fifth of all water used in the world is obtained from groundwater. The protection of water has become a high priority goal. During the last decades pollution of water has become more and more severe. Today groundwater is more and more used in comparison with surface water. Recently we have seen accidents, which can pollute nearly all surface water very quickly. Generally the groundwater is easier to protect, as well as cheaper to purify, and above all it is of better quality than the surface water. During the past two decades, alternatives to the traditional method of treating the water in filters have been developed, that is in situ water treatment i.e. the VYREDOX and NITREDOX methods. The most common problem regarding groundwater is too high content of iron and manganese, which can be reduced with the VYREDOX method. In some areas today there are severe problems with pollution by hydrocarbons and nitrate as well, and with modification of the VYREDOX treatment method it is used for hydrocarbon and nitrate treatment as well. The method to reduce the nitrate and nitrite is known as the NITREDOX method.

Mapping the relative risk of surface water acidification based on cumulative acid deposition over the past 25 years in Japan

2016 ◽  
Vol 21 (3) ◽  
pp. 115-124 ◽  
Author(s):  
Naoyuki Yamashita ◽  
Hiroyuki Sase ◽  
Tsuyoshi Ohizumi ◽  
Junichi Kurokawa ◽  
Toshimasa Ohara ◽  
...  
Keyword(s):  
Relative Risk ◽  
Surface Water ◽  
Acid Deposition ◽  
Water Acidification ◽  
The Past ◽  
Surface Water Acidification

scholarly journals Sea ice ridging over the Alaskan Continental Shelf

1979 ◽  
Vol 84 (C8) ◽  
pp. 4885 ◽  
Author(s):  
W. B. Tucker ◽  
W. F. Weeks ◽  
M. Frank
Keyword(s):  
Sea Ice ◽  
Continental Shelf

scholarly journals Sedimentary ancient DNA from Kronotsky Peninsula: how sea ice, salinity and insolation dynamics have shaped diatom composition and richness over the past 20,000 years

2020 ◽  
Author(s):  
Heike H. Zimmermann ◽  
Kathleen R. Stoof-Leichsenring ◽  
Stefan Kruse ◽  
Dirk Nürnberg ◽  
Ralf Tiedemann ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ancient Dna ◽  
The Past

scholarly journals How Effective Are Existing Phosphorus Management Strategies in Mitigating Surface Water Quality Problems in the U.S.?

2021 ◽  
Vol 13 (12) ◽  
pp. 6565
Author(s):  
Shama E. Haque
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Management Strategies ◽  
Surface Water Quality ◽  
Land Application ◽  
Water Soluble ◽  
Phosphorus Recovery ◽  
Water Bodies ◽  
The Past ◽  
The U.S

Phosphorus is an essential component of modern agriculture. Long-term land application of phosphorous-enriched fertilizers and animal manure leads to phosphorus accumulation in soil that may become susceptible to mobilization via erosion, surface runoff and subsurface leaching. Globally, highly water-soluble phosphorus fertilizers used in agriculture have contributed to eutrophication and hypoxia in surface waters. This paper provides an overview of the literature relevant to the advances in phosphorous management strategies and surface water quality problems in the U.S. Over the past several decades, significant advances have been made to control phosphorus discharge into surface water bodies of the U.S. However, the current use of phosphorus remains inefficient at various stages of its life cycle, and phosphorus continues to remain a widespread problem in many water bodies, including the Gulf of Mexico and Lake Erie. In particular, the Midwestern Corn Belt region of the U.S. is a hotspot of phosphorous fertilization that has resulted in a net positive soil phosphorous balance. The runoff of phosphorous has resulted in dense blooms of toxic, odor-causing phytoplankton that deteriorate water quality. In the past, considerable attention was focused on improving the water quality of freshwater bodies and estuaries by reducing inputs of phosphorus alone. However, new research suggests that strategies controlling the two main nutrients, phosphorus and nitrogen, are more effective in the management of eutrophication. There is no specific solution to solving phosphorus pollution of water resources; however, sustainable management of phosphorus requires an integrated approach combining at least a reduction in consumption levels, source management, more specific regime-based nutrient criteria, routine soil fertility evaluation and recommendations, transport management, as well as the development of extensive phosphorus recovery and recycling programs.

scholarly journals Biomass uptake and fire as controls on groundwater solute evolution on a southeast Australian granite: aboriginal land management hypothesis

2014 ◽  
Vol 11 (15) ◽  
pp. 4099-4114 ◽  
Author(s):  
J. F. Dean ◽  
J. A. Webb ◽  
G. E. Jacobsen ◽  
R. Chisari ◽  
P. E. Dresel
Keyword(s):  
Surface Water ◽  
Plant Uptake ◽  
Plant Biomass ◽  
Chemical Species ◽  
Nutrient Elements ◽  
Surface Water Chemistry ◽  
Climatic Regions ◽  
The Past ◽  
Geochemical Mass Balance ◽  
Granite Terrain

Abstract. The chemical composition of groundwater and surface water is often considered to be dominated by water–rock interactions, particularly weathering; however, it has been increasingly realised that plant uptake can deplete groundwater and surface water of nutrient elements. Here we show, using geochemical mass balance techniques, that water–rock interactions do not control the hydrochemistry at our study site within a granite terrain in southwest Victoria, Australia. Instead the chemical species provided by rainfall are depleted by plant biomass uptake and exported, predominantly through fire. Regular landscape burning by Aboriginal land users is hypothesized to have caused the depletion of chemical species in groundwater for at least the past 20 000 yr by accelerating the export of elements that would otherwise have been stored within the local biomass. These findings are likely to be applicable to silicate terrains throughout southeast Australia, as well as similar lithological and climatic regions elsewhere in the globe, and contrast with studies of groundwater and surface water chemistry in higher rainfall areas of the Northern Hemisphere, where water–rock interactions are the dominant hydrochemical control.

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