scholarly journals The role of rapid glacier retreat and landscape transformation in controlling the post-Little Ice Age evolution of paraglacial coasts in central Spitsbergen (Billefjorden, Svalbard)

2018 ◽  
Vol 29 (6) ◽  
pp. 1962-1978 ◽  
Author(s):  
Mateusz C. Strzelecki ◽  
Antony J. Long ◽  
Jeremy M. Lloyd ◽  
Jakub Małecki ◽  
Piotr Zagórski ◽  
...  
Keyword(s):  
Little Ice Age ◽  
Glacier Retreat ◽  
Ice Age ◽  
Landscape Transformation

scholarly journals Simulated retreat of Jakobshavn Isbræ since the Little Ice Age controlled by geometry

2018 ◽  
Vol 12 (7) ◽  
pp. 2249-2266 ◽  
Author(s):  
Nadine Steiger ◽  
Kerim H. Nisancioglu ◽  
Henning Åkesson ◽  
Basile de Fleurian ◽  
Faezeh M. Nick
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Climate Forcing ◽  
Relative Role ◽  
Regional Warming ◽  
History Of ◽  
The Impact ◽  
Term Response

Abstract. Rapid retreat of Greenland's marine-terminating glaciers coincides with regional warming trends, which have broadly been used to explain these rapid changes. However, outlet glaciers within similar climate regimes experience widely contrasting retreat patterns, suggesting that the local fjord geometry could be an important additional factor. To assess the relative role of climate and fjord geometry, we use the retreat history of Jakobshavn Isbræ, West Greenland, since the Little Ice Age (LIA) maximum in 1850 as a baseline for the parameterization of a depth- and width-integrated ice flow model. The impact of fjord geometry is isolated by using a linearly increasing climate forcing since the LIA and testing a range of simplified geometries. We find that the total length of retreat is determined by external factors – such as hydrofracturing, submarine melt and buttressing by sea ice – whereas the retreat pattern is governed by the fjord geometry. Narrow and shallow areas provide pinning points and cause delayed but rapid retreat without additional climate warming, after decades of grounding line stability. We suggest that these geometric pinning points may be used to locate potential sites for moraine formation and to predict the long-term response of the glacier. As a consequence, to assess the impact of climate on the retreat history of a glacier, each system has to be analyzed with knowledge of its historic retreat and the local fjord geometry.

Drastic glacier retreat at Pico de Orizaba (19º N, Mexico) since the Little Ice Age

2020 ◽  
Author(s):  
Jesús Alcalá Reygosa ◽  
Néstor Campos ◽  
Melaine Le Roy ◽  
Bijeesh Kozhikkodan Veettil ◽  
Adam Emmer
Keyword(s):  
Little Ice Age ◽  
Satellite Images ◽  
Physical Geography ◽  
Glacier Retreat ◽  
Ice Age ◽  
Glacier Area ◽  
Tropical Andes ◽  
Bolivian Andes ◽  
The Alps

<p>The Little Ice Age (LIA) occurred between CE 1250 and 1850 and is considered a period of moderate cold conditions, especially recorded in the northern hemisphere. Numerous recent studies provide robust evidence of glacier advances worldwide during the LIA and a dramatic retreat since then. These studies combined investigation of moraine records, paintings, topographical and glaciological measurements as well as multitemporal aerial and terrestrial photographs and satellite images. For instance, post-LIA glaciers retreat amounts ~60 % in the Alps (Paul et al., 2020), ~88 % in the Pyrenees (Rico et al., 2016) and 89 % in the Bolivian Andes (Ramírez et al., 2001). However, there is scarce knowledge in Mexico about the glacier changes since the LIA. The reconstructions are limited to the Iztaccíhualt volcano where Schneider et al. (2008) established a glacier retreat of 95 %.</p><p>Here, we reconstruct the glacier evolution since the LIA to CE 2015 of the Mexican highest ice-capped volcano: Pico de Orizaba (19° 01´ N, 97° 16´W, 5,675 m a.s.l.). Due to Pico de Orizaba is in the outer Tropic, the most plausible scenario is a glacier evolution similar to the Bolivian Andes and especially to the Iztaccíhualt volcano. To carry out this research, we mapped the glacier area during the LIA, based on moraine record, and the area during 1945, 1958, 1971, 1988, 1994, 2003 and 2015 using a previous map elaborated by Palacios and Vázquez-Selem (1996), aerial orthophotographs and satellite images. The geographical mapping and the calculus of area, minimum altitude and volume of the glacier were generated with the software ArcGIS 10.2.2. The results show that glacier area retreated 92% between the LIA (8.8 km<sup>2</sup>) and 2015 (0.67 km<sup>2</sup>), being a drastic glacier loss in agreement with the Bolivian Andes and Iztaccíhualt. Therefore, mexican glaciers have experienced the major shrunk since LIA that implies a highly sensitive reaction to global warming.</p><p>This research was supported by the Project UNAM-DGAPA-PAPIIT grant IA105318.</p><p>References</p><p>Palacios, D., Vázquez-Selem, L. 1996. Geomorphic effects of the retreat of Jamapa glacier, Pico de Orizaba volcano (Mexico). Geografiska Annaler, Series A, Physical Geography 78, 19-34.</p><p>Paul F., Rastner P., Azzoni R.S., Diolaiuti G., Fugazza D., Le Bris R., Nemec J., Rabatel A., Ramusovic M., Schwaizer G., and Smiraglia C. 2020. Glacier shrinkage in the Alps continues unabated as revealed by a new glacier inventory from Sentinel-2 https://doi.org/10.5194/essd-2019-213.</p><p>Ramírez, E., Francou, B., Ribstein, P., Descloitres, M., Guérin, R., Mendoza, J., Gallaire, R., Pouyaud, B., Jordan, E. 2001. Small glaciers disappearing in the tropical Andes: a case study in Bolivia: Glaciar Chacaltaya (16° S). Journal of Glaciology 47 (157), 187-194.</p><p>Rico I., Izagirre E., Serrano E., López-Moreno J.I., 2016. Current glacier area in the Pyrenees : an updated assessment 2016. Pirineos 172, doi: http://dx.doi.org/10.3989/Pirineos.2017.172004.</p><p>Schneider, D., Delgado-Granados, H., Huggel, C., Kääb, A. 2008. Assessing lahars from ice-capped volcanoes using ASTER satellite data, the SRTM DTM and two different flow models: case study on Iztaccíhuatl (Central Mexico). Natural Hazards and Earth System Sciences 8, 559-571.</p><p> </p><p> </p>

scholarly journals A importância da acção do frio do Quaternário final em Portugal e suas implicações nas morfodinâmicas de vertente.

2012 ◽  
Vol 5 (2) ◽  
pp. 421
Author(s):  
António Sousa Pedrosa
Keyword(s):  
Little Ice Age ◽  
Late Quaternary ◽  
Climatic Conditions ◽  
Ice Age ◽  
Glacial Deposits ◽  
Central Portugal

Resumo   De entre os  factores que tiveram maior influência na evolução do relevo de Portugal no decurso final do Quaternário é incontestável que o frio e os processos que lhe estão associados tiveram um papel muito importante na modelação das formas de relevo. Neste trabalho procuraremos fazer uma síntese dos principais aspectos da evolução das vertentes relacionados com os frio, inferir através dos vestígios que chegaram até ao nossos dias quais as condições morfo-climáticas em que ocorreram e quais os processos que lhes estavam encontravam associados. Realçamos assim o papel da acção dos glaciares nas áreas onde ocorreram assim como a importância dos processos periglaciares na evolução das vertentes. O período tardiglaciar também se mostrou marcante na dinâmica de vertentes tendo mobilizado e remobilizado muito material nas vertentes através de solifluxões generalizadas levando muitas delas à sua regularização. O período conhecido como a pequena idade do gelo também deixou as suas marcas na dinâmica das vertentes às quais se associam as escombreiras de gravidade. Por fim enfatizamos um pouco o papel do frio na actual morfodinâmica de vertentes no Norte de Centro de Portugal.   Palavras-chave: Norte de Portugal; Montanhas, depósitos glaciares, depósitos periglaciares, dinâmica de vertentes Summary   Among the factors that most influenced the evolution of the relief of Portugal during the late Quaternary is incontestable that the cold and the processes associated with it had a very important role in modeling the forms of relief. In this paper, we will try to summarize the importance that the cold had on the evolution of slopes, inferred through the vestiges that have come down to our day, which morpho-climatic conditions in which they occur, and also what processes if they were associated with. Thus enhancing the role of action in areas where glaciers have occurred and the importance of periglacial processes in the evolution of the slopes. In tardiglaciar the dynamics of slopes was very active and mobilized a lot of material through the process of solifluction regularized many of them. The period known as the Little Ice Age has also left its mark on the dynamic slopes which relate to tailings heaps of gravity. Finally we emphasize the role of cold in the current slopes of morphodynamics in north and central Portugal.   Keywords: North of Portugal; mountains, glacial deposits, periglacial deposits, morphodynamics of slopes 

scholarly journals Timing of Little Ice Age maxima and subsequent glacier retreat in northern Troms and western Finnmark, northern Norway

2020 ◽  
Vol 52 (1) ◽  
pp. 281-311
Author(s):  
J. R. Leigh ◽  
C. R. Stokes ◽  
D. J. A. Evans ◽  
R. J. Carr ◽  
L. M. Andreassen
Keyword(s):  
Little Ice Age ◽  
Glacier Retreat ◽  
Ice Age ◽  
Northern Norway

scholarly journals Little Ice Age glacial geomorphology and sedimentology of Portage Glacier, South-Central Alaska

Finisterra ◽  
2012 ◽  
Vol 44 (87) ◽  
Author(s):  
João Santos ◽  
Carlos Córdova
Keyword(s):  
Little Ice Age ◽  
Ice Sheets ◽  
Glacier Retreat ◽  
Ice Age ◽  
Glacial Geomorphology ◽  
South Central ◽  
Glacier Valley ◽  
Glacial Landforms ◽  
Basal Till ◽  
Insight Into

The study of glacial landforms and deposits is important, as it is difficult to observe processes under modern glaciers and ice-sheets. Thus landscapes and sediments that are the product of present glaciation can give insight into processes that occurred during  pleistocene times. This study investigates the genesis of little ice age glacial landforms present in portage Glacier, South-central Alaska. The present day moraine morphology and sedimentology in portage Glacier valley reveals the presence of two types of till and moraines. The clast-rich sandy diamicton present on the 1852 moraine is interpreted to be a basal till indicating this feature is a push moraine representing an advance or a standstill position of portage Glacier in 1852. The moderately sorted gray sandy boulder gravel present on the 1900 and 1922 moraines is interpreted to be an ice-marginal deposit (ablation till) with a mixture of supraglacial and glaciofluvial sediments deposited by slumping and stream sorting processes. All of these features are interpreted to be ablation moraines representing glacier retreat and moraine building in 1900 and1922.

scholarly journals The geomorphological role of snow since the Little Ice Age in the Sierra de Ancares (NW Spain)

2018 ◽  
Vol 44 (1) ◽  
pp. 171 ◽  
Author(s):  
P. Carrera-Gómez ◽  
M. Valcárcel
Keyword(s):  
Snow Cover ◽  
Little Ice Age ◽  
Ice Age ◽  
Nw Spain ◽  
Seasonal Snow ◽  
Snow Precipitation ◽  
Prior Construction ◽  
Seasonal Snow Cover ◽  
Rapid Mass

On the Pico Cuiña cirque, Sierra de Ancares (León, Spain), the seasonal snow cover undergoes both slow and rapid mass displacements. Push associated with moving snow is responsible for an intense geomorphological activity, which is characterised by the plucking and transport of fragments of the bedrock, the abrasion of rock surfaces and the deposition of the mobilized material. Pronival ramparts are the most characteristic accumulation geoform created by pushing snow. Its study enabled us to verify the functionality of the nival processes and to prove the relative antiquity of some of them. The use of lichenometric techniques, based on the prior construction of a growth curve for lichens of the Rhizocarpon subgenus, has made possible to date sectors of the pronival ramparts. Lichenometric dates show a series of events of geomorphic activity of the snow cover fitting chronologically within the so-called Little Ice Age. It can be deduced from the observation of the current geomorphic dynamics of the snow cover that, although Little Ice Age temperature decrease might be important, particularly in the summer, the role of the variations in snow precipitation must be also taken into consideration.

Post-Little Ice Age retreat of glaciers triggered rapid paraglacial landscape transformation in Sørkapp Land (Spitsbergen)

2020 ◽  
Author(s):  
Justyna Dudek ◽  
Mateusz Czesław Strzelecki
Keyword(s):  
Little Ice Age ◽  
Remote Sensing Data ◽  
Spatial Diversity ◽  
Ice Age ◽  
The Arctic ◽  
Rapid Reduction ◽  
Glacier Recession ◽  
Landscape Transformation ◽  
Glacial Landforms ◽  
Marginal Zones

<p>Contemporary climate warming in the Arctic affects the dynamics of the entire environment, including components of the cryosphere: permafrost and glacier systems. The change in the structure of the polar landscape since the termination of the Little Ice Age (ca. 1900) was expressed by widespread retreat of glaciers, progressive exposure of glacial landforms at ice margins and opening ice marginal zones to increasing paraglacial and periglacial processes operating synchronously in adjacent areas.</p><p>The main aim of the presented study was to determine the course and spatial diversity of landscape transformation in the Sørkapp Land peninsula (Spitsbergen) as a result of glacier recession in the periods 1961-1990-2010 based on existing remote sensing data. Using photogrammetric methods of data processing combined with GIS techniques, the rates of proglacial and ice-marginal terrain change following deglaciation have been determined.</p><p>For the mentioned research period, the area of the marginal zones almost doubled from 53 km² to 99 km². The dynamics of landscape transformation in these zones manifested in rapid reduction in the surface elevation of ice-cored moraines (with mean decrease of 0,18-0,22 m per year) and the forms underlain by the dead-ice. This process was enhanced by mass movements and debris flows. Within marginal zones, the area of subglacial landforms and sediments increased by 31 km² from 8 km² in 1961 to 39 km² in 2010.</p><p>Larger volume of proglacial waters and associated intensification of denudation, transport and accumulation of sediments entailed area increase of sandurs and proglacial riverbeds (which almost tripled from 3,5 km² to over 10 km²). Further redeposition and remobilization of material in some places also promoted enhanced sediment aggradation in coastal environment forming new beaches and spit systems.</p>

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