Glacier variations 1930–1970, 1970–1995, 1995–2017 and 2017–2018

JOKULL ◽  
2020 ◽  
Vol 69 ◽  
pp. 129-136
Author(s):  
Hrafnhildur Hannesdóttir

Glacier variations 1930–1970, 1970–1995, 1995–2017 and 2017–2018 The Icelandic Glaciological Society received reports on 46 measurements sites of glacier front variations in the autumn of 2018. Glacier retreat was observed at 33 survey sites whereas advances where reported from 5 sites, and 4 showed no signs of change. Snow covered glacier margins, bad weather or floating icebergs in the proglacial lakes prevented measurement at a few sites. One new site was added to the network, the western part of Þórisjökull.

JOKULL ◽  
2021 ◽  
Vol 70 ◽  
pp. 111-118
Author(s):  
Hrafnhildur Hannesdottir

The Icelandic Glaciological Society received reports on approximately 50 measurements sites of glacier front variations in the autumn of 2019. Glacier retreat was observed at 80% of survey sites whereas advances where reported from 4 sites. The warm summer led to fewer snow-covered glacier margins, and more successful surveys. As in recent years the proglacial lakes make terminus measurements more difficult, although the laser rangefinder works well.


2020 ◽  
Author(s):  
Saule Akhmetkaliyeva ◽  
Robert Sparkes ◽  
Leon Clarke ◽  
Andrew Dean ◽  
Simon Cook

<p>Arctic and sub-arctic regions contain a globally significant reservoir of easily degradable glacial organic carbon (GOC) held within glacier ice, subglacial sediments, and proglacial sediments and soils. 21st century warming will result in global glacier retreat with the potential to expose and release GOC, degradation of which can produce CO<sub>2</sub> and/or CH<sub>4</sub> through physical, chemical or biological processes. Newly-exposed nutrient rich glacial landscapes may develop soils and ecosystems. However, current understanding of the nature of glacial carbon cycling is very weak. In this study, sources and transformations of organic carbon (OC) within proglacial environments were determined using a combination of organic biomarkers, DNA sequencing and elemental concentrations.</p><p>Soil development was characterised in three contrasting glacial systems (Oræfajökull ice cap in Iceland, Tarfala in Sweden and Zackenberg in Greenland) in order to understand the main source of OC in soils exposed after glacier retreat and soil development along downstream transects from the glacier front. Water, soil and sediment samples were collected during four successful field campaigns (Iceland and Sweden in summer 2018, Greenland and Iceland in summer 2019). Soil and sediment samples were analysed for organic carbon and nitrogen concentrations, bacteriohopanepolyol biomarkers (BHPs), a group of membrane lipids that can be used to trace major microbial groups, DNA sequencing and major elements (using ICP-OES and IC).  </p><p>Soil samples from moraines showed highest OC concentrations (up to 5.5% in Iceland), while fluvial sediment samples from all study areas had low to no OC. BHPs were rare in fluvial sediments, observed in riverbank soils and most common in moraines. Both total BHP concentration and R’soil index (up to 50.5 µg/g ΣBHPs in a Little Ice Age and 0.41 R’soil in a 2500-year-old Icelandic moraines) show development of soils over time along the downstream transect from the glacier front. DNA concentrations in soil extracts are much higher than fluvial sediment samples. Particulate OC concentration in glacial meltwater streams and proglacial lakes was low (up to 0.03 mg/L), perhaps due to the high total suspended sediment concentrations (up to 0.96 mg/L) in most of the streams. Water chemistry analyses showed significant Ca, S, Na, Fe, Mg and Al concentrations, that potentially would fertilise the Arctic Ocean.</p><p>Based on these preliminary data, it can be concluded that direct glacial output of organic carbon is low, but soil and ecosystem development in front of retreating glaciers leads to the build-up of new terrestrial OC stores. Erosion of OC from these pro-glacial landscapes by glacial meltwater might highly affect estimates of GOC. Future glacier retreat in deglaciating systems in the Arctic (Greenland and Sweden) and sub-arctic (Iceland) regions might increase terrestrial OC productivity and carbon export, as well as seeding biological production downstream.</p>


1966 ◽  
Vol 27 ◽  
pp. 163-165
Author(s):  
Dr H. W. Babcock
Keyword(s):  

BABCOCK: On behalf of the Mt Wilson and Palomar group, I'd like to welcome all of you who braved this bad weather. We weren't quite counting on this deluge, but we will go ahead with the program as arranged.


Liquidity ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Siti Maryama

The purpose of the study are to (1) review the main problems faced by the factory of Kepuruk Manunggal Karsa (MK), and (2) assessing the entrepreneur attempts to be able to solve the problems faced. The research was carried out using qualitative descriptive design. The results showed that (1) the lack of supply of raw materials as a result of lack of capital. Sequel is due, the difficulty of the plant to meet consumer demand (excess demand). (2), the system of capital used is circulating capital (capital turnover). Earned income used up to finance the operation of the plant. (3) Innovation has been done in the form of deal with bad weather (rain) as an effort of crackers drying process is by using the oven. (4) There has been no cooperation with financial institutions. (5) There is no organizational structure as a modern factory for traditionally managed by family management. (6) Marketing using modes of transportation carts and motor vehicles.


2020 ◽  
Vol 2020 (1) ◽  
pp. 78-81
Author(s):  
Simone Zini ◽  
Simone Bianco ◽  
Raimondo Schettini

Rain removal from pictures taken under bad weather conditions is a challenging task that aims to improve the overall quality and visibility of a scene. The enhanced images usually constitute the input for subsequent Computer Vision tasks such as detection and classification. In this paper, we present a Convolutional Neural Network, based on the Pix2Pix model, for rain streaks removal from images, with specific interest in evaluating the results of the processing operation with respect to the Optical Character Recognition (OCR) task. In particular, we present a way to generate a rainy version of the Street View Text Dataset (R-SVTD) for "text detection and recognition" evaluation in bad weather conditions. Experimental results on this dataset show that our model is able to outperform the state of the art in terms of two commonly used image quality metrics, and that it is capable to improve the performances of an OCR model to detect and recognise text in the wild.


Author(s):  
Brian Chadwick ◽  
Adam A. Garde ◽  
John Grocott ◽  
Ken J.W. McCaffrey ◽  
Mike A. Hamilton

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Chadwick, B., Garde, A. A., Grocott, J., McCaffrey, K. J., & Hamilton, M. A. (2000). Ketilidian structure and the rapakivi suite between Lindenow Fjord and Kap Farvel, South-East Greenland. Geology of Greenland Survey Bulletin, 186, 50-59. https://doi.org/10.34194/ggub.v186.5215 _______________ The southern tip of Greenland is underlain by the Palaeoproterozoic Ketilidian orogen (e.g. Chadwick & Garde 1996; Garde et al. 1998a). Field investigations in the summer of 1999 were focused on the structure of migmatites (metatexites) and garnetiferous granites (diatexites) of the Pelite Zone in the coastal region of South-East Greenland between Lindenow Fjord and Kap Farvel (Figs 1, 2). Here, we first address the tectonic evolution in the Pelite Zone in that region and its correlation with that in the Psammite Zone further north. Then, the structure and intrusive relationships of the rapakivi suite in the Pelite Zone are discussed, including particular reference to the interpretation of the controversial outcrop on Qernertoq (Figs 2, 8). Studies of the structure of the north-eastern part of the Julianehåb batholith around Qulleq were continued briefly from 1998 but are not addressed here (Fig. 1; Garde et al. 1999). The field study was keyed to an interpretation of the Ketilidian orogen as a whole, including controls of rates of thermal and tectonic processes in convergent settings. Earlier Survey field work (project SUPRASYD, 1992–1996) had as its principal target an evaluation of the economic potential of the orogen (Nielsen et al. 1993). Ensuing plate-tectonic studies were mainly funded in 1997–1998 by Danish research foundations and in 1999 by the Natural Environment Research Council, UK. The five-week programme in 1999 was seriously disrupted by bad weather, common in this part of Greenland, and our objectives were only just achieved. Telestation Prins Christian Sund was the base for our operations (Fig. 2), which were flown with a small helicopter (Hughes MD-500).


1983 ◽  
Vol 29 (103) ◽  
pp. 515-520
Author(s):  
J. N. J. Visser

Abstract The upper part of a Permo-Carboniferous glacial valley fill along the northern margin of the Karoo Basin includes glacio-lacustrine sediments. During the last glacier advance into the lake, a bedded heterogeneous diamictite facies was deposited and, on glacier retreat, a sequence of deformed siltstones with diamictite lenses and sandstone beds, varved shale and rhythmite shale was laid down. Black carbonaceous mud was deposited during the subsequent marine transgression. According to varve counts, the glacier receded from the valley over a period of 500 to 1 000 years and it is concluded that the overall ice-retreat rate during the Permo-Carboniferous deglaciation was relatively high.


Author(s):  
Mauro Gobbi ◽  
Valeria Lencioni

Carabid beetles and chironomid midges are two dominant cold-adapted taxa, respectively on glacier forefiel terrains and in glacial-stream rivers. Although their sensitivity to high altitude climate warming is well known, no studies compare the species assemblages exhibited in glacial systems. Our study compares diversity and distributional patterns of carabids and chironomids in the foreland of the receding Amola glacier in central-eastern Italian Alps. Carabids were sampled by pitfall traps; chironomids by kick sampling in sites located at the same distance from the glacier as the terrestrial ones. The distance from the glacier front was considered as a proxy for time since deglaciation since these variables are positively correlated. We tested if the distance from the glacier front affects: i) the species richness; ii) taxonomic diversity; and iii) species turnover. Carabid species richness and taxonomic diversity increased positively from recently deglaciated sites (those c. 160 m from the glacier front) to sites deglaciated more than 160yrs ago (those located >1300 m from glacier front). Species distributions along the glacier foreland were characterized by mutually exclusive species. Conversely, no pattern in chironomid species richness and turnover was observed. Interestingly, taxonomic diversity increased significantly: closely related species were found near the glacier front, while the most taxonomically diverse species assemblages were found distant from the glacier front. Increasing glacial retreat differently affect epigeic and aquatic insect taxa: carabids respond faster to glacier retreat than do chironomids, at least in species richness and species turnover patterns.


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