Glacier variations 1930-1970, 1970-1995, 1995-2018 and 2018-2019

JOKULL ◽  
2021 ◽  
Vol 70 ◽  
pp. 111-118
Author(s):  
Hrafnhildur Hannesdottir
Keyword(s):  
Glacier Retreat ◽  
Laser Rangefinder ◽  
Proglacial Lakes ◽  
Warm Summer ◽  
Glacier Front

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.

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

JOKULL ◽  
2020 ◽  
Vol 69 ◽  
pp. 129-136
Author(s):  
Hrafnhildur Hannesdóttir
Keyword(s):  
Glacier Retreat ◽  
Proglacial Lakes ◽  
Glacier Front ◽  
Bad Weather

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.

Quantifying and characterising organic carbon in newly-developed soils following glacier retreat in northern latitudes

2020 ◽  
Author(s):  
Saule Akhmetkaliyeva ◽  
Robert Sparkes ◽  
Leon Clarke ◽  
Andrew Dean ◽  
Simon Cook
Keyword(s):  
Organic Carbon ◽  
Dna Sequencing ◽  
Soil Development ◽  
Glacier Retreat ◽  
The Arctic ◽  
Glacial Meltwater ◽  
Fluvial Sediment ◽  
Sediment Samples ◽  
Glacier Front ◽  
Soil And Sediment

<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>

Introduction

2017 ◽  
Author(s):  
George Hoffmann
Keyword(s):  
Chief Editor ◽  
City Council ◽  
The West ◽  
Son Of God ◽  
Warm Summer ◽  
The City

On a warm summer afternoon in 1561, Calvin’s chief editor donned a heavy stole, thick robes, and a gleaming tiara and proceeded to strut and fret his hour upon the stage in a comedy of his own devising. For little more than a century, Christians in the West had celebrated on August 6th Christ’s Transfiguration as the son of God in shining robes. But on this Sunday in Geneva, the city council, consistory, and an audience fresh from having attended edifying sermons at morning service gathered to applaud the transfiguration of the learned Conrad Badius into the title role of ...

scholarly journals A Lacustrine Glacier Retreat Sequence from the Permo-Carboniferous Dwyka Formation, Republic of South Africa

1983 ◽  
Vol 29 (103) ◽  
pp. 515-520
Author(s):  
J. N. J. Visser
Keyword(s):  
South Africa ◽  
Lacustrine Sediments ◽  
Glacier Retreat ◽  
Marine Transgression ◽  
Northern Margin ◽  
Valley Fill ◽  
Karoo Basin ◽  
Ice Retreat ◽  
Glacier Advance

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.

scholarly journals Do carabids (Coleoptera: Carabidae) and chironomids (Diptera: Chironomidae) exhibit similar diversity and distributional patterns along a spatio-temporal gradient on a glacier foreland?

2018 ◽  
Author(s):  
Mauro Gobbi ◽  
Valeria Lencioni
Keyword(s):  
Species Richness ◽  
Species Turnover ◽  
Aquatic Insect ◽  
Taxonomic Diversity ◽  
Carabid Beetles ◽  
Species Assemblages ◽  
Glacier Foreland ◽  
Distributional Patterns ◽  
Glacier Front ◽  
Spatio Temporal

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.

scholarly journals Shift in polar benthic community structure in a fast retreating glacial area of Marian Cove, West Antarctica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanna Bae ◽  
In-Young Ahn ◽  
Jinsoon Park ◽  
Sung Joon Song ◽  
Junsung Noh ◽  
...  
Keyword(s):  
Community Structure ◽  
Benthic Community ◽  
Adaptive Strategy ◽  
Ecological Impacts ◽  
Glacier Retreat ◽  
Benthic Diatoms ◽  
Subtidal Zone ◽  
Benthic Community Structure ◽  
Community Shift ◽  
Global Issue

AbstractGlacier retreat is a major long-standing global issue; however, the ecological impacts of such retreats on marine organisms remain unanswered. Here, we examined changes to the polar benthic community structure of “diatoms” under current global warming in a recently retreated glacial area of Marian Cove, Antarctica. The environments and spatiotemporal assemblages of benthic diatoms surveyed in 2018–2019 significantly varied between the intertidal (tidal height of 2.5 m) and subtidal zone (10 and 30 m). A distinct floral distribution along the cove (~ 4.5 km) was characterized by the adaptive strategy of species present, with chain-forming species predominating near the glacier. The predominant chain-forming diatoms, such as Fragilaria striatula and Paralia sp., are widely distributed in the innermost cove over years, indicating sensitive responses of benthic species to the fast-evolving polar environment. The site-specific and substrate-dependent distributions of certain indicator species (e.g., F. striatula, Navicula glaciei, Cocconeis cf. pinnata) generally reflected such shifts in the benthic community. Our review revealed that the inner glacier region reflected trophic association, featured with higher diversity, abundance, and biomass of benthic diatoms and macrofauna. Overall, the polar benthic community shift observed along the cove generally represented changing environmental conditions, (in)directly linked to ice-melting due to the recent glacier retreat.

Design and Development of a Pulsed CO2 Laser Rangefinder

1988 ◽  
Vol 17 (4) ◽  
pp. 91-93
Author(s):  
D. P. Juyal ◽  
N. K. Barthwal ◽  
A. L. Singh ◽  
S. P. Gupta ◽  
M. T. Rudrappa ◽  
...  
Keyword(s):  
Co2 Laser ◽  
Laser Rangefinder ◽  
Design And Development ◽  
Pulsed Co2 Laser

scholarly journals Performance Verification of a Target Tracking System With a Laser Rangefinder

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 30993-31009
Author(s):  
Jihoon Lee ◽  
Suwon Lee ◽  
Youngjun Lee ◽  
Youdan Kim ◽  
Yongjun Heo ◽  
...  
Keyword(s):  
Target Tracking ◽  
Tracking System ◽  
Laser Rangefinder ◽  
Performance Verification

scholarly journals Salicylic acid and kaolin effects on pomological, physiological, and phytochemical characters of hazelnut (Corylus avellana) at warm summer condition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marziyeh Khavari ◽  
Reza Fatahi ◽  
Zabihollah Zamani
Keyword(s):  
Salicylic Acid ◽  
Crop Production ◽  
Corylus Avellana ◽  
Kernel Weight ◽  
Population Increase ◽  
Tolerance Index ◽  
Biotic And Abiotic Stresses ◽  
The World ◽  
Warm Summer ◽  
Supporting Materials

AbstractClimate change and population increase are two challenges for crop production in the world. Hazelnut (Corylus avellana L.) is considered an important nut regarding its nutritional and economic values. As a fact, the application of supporting materials as foliage sprays on plants will decrease biotic and abiotic stresses. In this study, the effects of salicylic acid (0, 1 mM and 2.5 mM) and kaolin (0, 3% and 6%) sprays were investigated on morphological, physiological, pomological, and biochemical characteristics of hazelnut. The results showed that 1 mM salicylic acid and 6% kaolin had the best effects on nut and kernel weight compared to control. Biochemical parameters such as chlorophyll a, b, a + b, and carotenoid contents showed that salicylic acid and kaolin improved pigment concentration. Proline and antioxidant contents such as phenolic acids, SOD, APX, and CAT enzyme activities increased by these applications. On the other hand, lipid peroxidation, protein content, and H2O2 content were decreased. Based on the tolerance index result, Merveille de Bollwiller cultivar showed the highest tolerance while 'Fertile de Coutard' had the lowest value. Therefore, hazelnut performance may be improved through exogenous application of the signaling (salicylic acid) and particle film (Kaolin) compounds in warmer climates.

scholarly journals Glacier Geometry Changes in the Western Shore of Admiralty Bay, King George Island over the Last Decades

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1532
Author(s):  
Mariusz Pasik ◽  
Krzysztof Bakuła ◽  
Sebastian Różycki ◽  
Wojciech Ostrowski ◽  
Maria Elżbieta Kowalska ◽  
...  
Keyword(s):  
Protected Area ◽  
Average Rate ◽  
King George Island ◽  
Glacier Surface ◽  
Glacial Retreat ◽  
Glacier Front ◽  
Longitudinal Slope ◽  
Western Shore ◽  
Rapid Temperature

This paper presents changes in the range and thickness of glaciers in Antarctic Specially Protected Area (ASPA) No. 128 on King George Island in the period 1956–2015. The research indicates an intensification of the glacial retreat process over the last two decades, with the rate depending on the type of glacier front. In the period 2001–2015, the average recession rate of the ice cliffs of the Ecology Glacier and the northern part of the Baranowski Glacier was estimated to be approximately 15–25 m a−1 and 10–20 m a−1, respectively. Fronts of Sphinx Glacier and the southern part of the Baranowski Glacier, characterized by a gentle descent onto land, show a significantly lower rate of retreat (up to 5–10 m a−1 1). From 2001 to 2013, the glacier thickness in these areas decreased at an average rate of 1.7–2.5 m a−1 for the Ecology Glacier and the northern part of the Baranowski Glacier and 0.8–2.5 m a−1 for the southern part of the Baranowski Glacier and Sphinx Glacier. The presented deglaciation processes are related to changes of mass balance caused by the rapid temperature increase (1.0 °C since 1948). The work also contains considerations related to the important role of the longitudinal slope of the glacier surface in the connection of the glacier thickness changes and the front recession.

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