Disappearance Of Glaciers Research Articles

An assessment of landform composition and functioning with the first proglacial systems dataset of the central European Alps

Proglacial systems are enlarging as glacier masses decline. They are in a transitory state from glacier-dominated to hillslope and fluvially-dominated geomorphological processes. They are a very important meltwater, sediment and solute source. This study makes the first quantitative, systematic and regional assessment of landform composition and functioning within proglacial systems that have developed in the short term since the Little Ice Age (LIA). Proglacial system extent was thus defined as the area between the LIA moraine ridges and the contemporary glacier. We achieved this assessment via a series of topographic analyses of 10 m resolution digital elevation models (DEMs) covering the central European Alps, specifically of Austria and Switzerland. Across the 2812 proglacial systems that have a combined area of 933 km2, the mean proportional area of each proglacial system that is directly affected by glacial meltwater is 37%. However, there are examples where there is no glacial meltwater influence whatsoever due to complete disappearance of glaciers since the LIA, and there are examples where >90% of the proglacial area is probably affected by glacial meltwater. In all of the major drainage basins; the Inn, Drava, Venetian Coast, Po, Rhine, Rhone and Danube, the proportions of the combined land area belonging to each landform class is remarkably similar, with >10% fluvial, ~35% alluvial and debris fans, ~50% moraine ridges and talus/scree, and ~10% bedrock, which will be very helpful for considering estimates of regional sediment yield and denudation rates. We find groupings of the relationship between proglacial system hypsometric index and lithology, and of a slope threshold discriminating between hillslope and fluvial-dominated terrain, both of which we interpret to be due to grain size. We estimate of contemporary total volume loss from all of these proglacial systems of 44 M m3a−1, which equates to a mean of 0.3 mm·a−1 contemporary surface lowering. Overall, these first quantifications of proglacial landform and landscape evolution will be an important basis for inter- and intra-catchment considerations of climate change effects on proglacial systems such as land stability, and changing water, sediment and solute source fluxes. Our datasets are made freely available.

Benjamin Wilke (ed): Stan Allen: Four Projects

The geologic surface is more vulnerable and unstable than ever before: we are facing an era when continental shifts, the disappearance of glaciers, the movement of mountains, and earthquakes and tsunamis are creating a new terrestrial crust and new landforms. Changes in geology and earth processes affects our environment as well as our daily life. What is the role of architecture in solving these urgent issues? What is the appropriate way to address these changes? Landform direction in architecture gives insight to an understanding of the environment, mankind’s relationship to landscape, and urbanism. The understanding of buildings as a link between people and nature bring even more value to this direction.

Glaciers: The Politics of Ice. By Jorge Daniel Taillant. Oxford and New York: Oxford University Press. $29.95. xxiii + 334 p.; ill.; index. ISBN: 978-0-19-936725-2. 2015.

Previous articleNext article FreeConservation BiologyGlaciers: The Politics of Ice. By Jorge Daniel Taillant. Oxford and New York: Oxford University Press. $29.95. xxiii + 334 p.; ill.; index. ISBN: 978-0-19-936725-2. 2015.Santiago de la PeñaSantiago de la PeñaByrd Polar & Climate Research Center, Ohio State University, Columbus, Ohio Search for more articles by this author Byrd Polar & Climate Research Center, Ohio State University, Columbus, OhioPDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreAt its core, Glaciers: The Politics of Ice is a recount of the events and the environmental activism work in Argentina that led to a legal and political movement culminating in the important glacier conservation law of 2010 that protects all glaciers in this Andean country. In an easy-to-follow and entertaining prose, the author describes the harmful effects that specifically industrial mining in the Andes was having on the glaciers of the region, and the steps taken to protect the glaciers legally from international conglomerates. The stories of how small changes were affecting the communities in the proximity of mining operations in the Andes is revealing, and the descriptions fit nicely into a regional context, with explanations of the impact that the disappearance of glaciers in the Andes is having on society.Although this law is certainly important and sets a precedent, there are a few personal accounts where I perceived a certain bias and maybe a bit of unconscious self-promotion, not a surprise given the role Taillant had in the movement, and the personal relationship he had with the environmental minister in the Argentinian government at the time of the enactment of the protection law. The author’s message about the damage that mining companies have done to the glaciers of Chile and Argentina is clear, and there is no doubt about the importance of the legislative work. However, Taillant does not really acknowledge the significant efforts done in other countries to protect glaciated areas. Although it is true that the Andean law explicitly protects glaciers regardless of size, in countries such as Norway, Denmark, Canada, and the United States, there is environmental legislation that has made whole glaciated regions protected reserves and national parks that not only protect the glacier itself, but also the whole ecosystem surrounding it. For instance, in Greenland, not only is mining not permitted near glaciers, the now autonomous government took away every single mining license a few years ago.The book also has the objective to introduce readers to glaciers and the science of glaciers. In a clear nod to Argentinian author Julio Cortázar, Taillant alternates the book chapters, describing in some the story of the glacier-protecting law and in others the principles of glaciers. In this last account the author fails to deliver. The descriptions are vague and there is too much missing information for it to be considered a textbook on glaciers. The specifics regarding glaciers in the Andes are the best section in these chapters, showing Taillant’s knowledge in the area, but there are too many references missing for this to be a comprehensive review of glacier science.Overall, this is a very interesting account, which could be considered from an insider’s perspective, of the environmental movement driving glacier protection in Argentina. It highlights some interesting facts about the local communities in the Andes and their relationship with glaciers and the mining companies that are threating them. I found myself wanting to get more details regarding these relationships, and the culture surrounding life in glaciated areas of the Andes. The effort made to include principles in glacier science is commendable, but ultimately makes it feel like you are reading two unfinished books instead of a more detailed one. Previous articleNext article DetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 92, Number 1March 2017 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/690861 For permission to reuse, please contact [email protected]PDF download Crossref reports no articles citing this article.

Temperature reconstruction from the length fluctuations of small glaciers in the eastern Alps (northeastern Italy)

In this study, a linear model computing the air temperature fluctuations from the measured glacier snout fluctuations has been applied, for the first time, to three small glaciers in the western Tauern Alps (eastern Alps) in the period 1929–2011. The considered glaciers, with areas between 0.2 and $$1.3\,\hbox {km}^2$$ , are characterized by relevant time variations of their morphology, length and slope. The model requires the knowledge of two parameters: the glacier climate sensitivity $$C_s$$ and the glacier response time $$\tau$$ , both depending on the glacier morphological characteristics and on the precipitation. Applied to the glaciers assuming $$C_s$$ and $$\tau$$ as in the original formulation, it underestimates the temperature increase of $${\approx } 1.8\,^{\circ }\hbox {C}$$ derived over the whole period from the in situ data. Given the characteristics of these small glaciers, these parameters have been recalibrated by means of a non-linear least-square regression using an independent set of glaciers. Their mean value is of about 210 m/K and 3.8 years respectively. With the recalibrated values of the new glacier climate sensitivity $$C^*_s$$ and response time $$\tau ^*$$ , the temperature fluctuations derived by the model reproduce well those obtained from the observed temperatures computed over the hydrological year, with linear correlations between 0.8 and 0.9. The increase of the modeled mean temperature over the whole period fits in with that derived from observed temperature. Considering that the length fluctuations of these small glaciers affect significantly their slope and length, we tested the impact in the model of a time dependent formulation of $$C_s$$ and $$\tau$$ : the results indicate slight improvements both in the values of the correlation between the reconstructed and the observed temperature fluctuations and in the global temperature increase. Given the above value of climate sensitivity, the large retreat of the small alpine glaciers threatens their survival within a few decades, but the morphological changes in progress may counteract the glacier disappearance.

New lakes in deglaciating high-mountain regions – opportunities and risks

In connection with the ongoing disappearance of glaciers in cold mountains, a great number of new lakes come into existence. The sites and approximate formation time of such potential new lakes can be realistically modelled. This provides an important knowledge base for planning the management of at least the larger ones among such lakes. New water bodies can markedly increase the hazard and risk potential for down-valley areas in the long term, especially in relation to impact/flood waves triggered by rock/ice avalanches from the steep icy peaks surrounding them. However, they also offer opportunities for use in connection with tourism, water supply and hydropower production. Legal regulations and aspects of landscape protection and nature conservation have to be thereby carefully considered. Possible synergies and conflicts exist; they can be anticipated at an early stage by a matrix-type analysis of interrelations between the different perspectives involved. A corresponding inter- and transdisciplinary study was performed for the currently glacierized areas of the Swiss Alps. The results of this study may serve as an example for dealing with the consequences of rapid climate-induced changes in other populated regions with rugged icy mountains, such as the Peruvian Cordilleras or the Himalaya-Karakoram region.

Impact of Climate Change on Vegetation Growth in Arid Northwest of China from 1982 to 2011

Previous studies have concluded that the increase in vegetation in the arid northwest of China is related to precipitation rather than temperature. However, these studies neglected the effects of climate warming on water availability that arise through changes in the melting characteristics of this snowy and glaciated region. Here, we characterized vegetation changes using the newly improved third-generation Global Inventory Modeling and Mapping Studies Normalized Difference Vegetation Index (GIMMS-3g NDVI) from 1982 to 2011. We analyzed the temperature and precipitation trends based on data from 51 meteorological stations across Northwest China and investigated changes in the glaciers using Gravity Recovery and Climate Experiment (GRACE) data. Our results indicated an increasing trend in vegetation greenness in Northwest China, and this increasing trend was mostly associated with increasing winter precipitation and summer temperature. We found that the mean annual temperature increased at a rate of 0.04 °C per year over the past 30 years, which induced rapid glacial melting. The total water storage measured by GRACE decreased by up to 8 mm yr−1 and primarily corresponded to the disappearance of glaciers. Considering the absence of any observed increase in precipitation in the growing season, the vegetation growth may have benefited from the melting of glaciers in high-elevation mountains (i.e., the Tianshan Mountains). Multiple regression analysis showed that temperature was positively correlated with NDVI and that gravity was negatively correlated with NDVI; together, these variables explained 84% of the NDVI variation. Our findings suggest that both winter precipitation and warming-induced glacial melting increased water availability to the arid vegetation in this region, resulting in enhanced greenness.

Modeling the hydrological response to climate change in a glacierized high mountain region, northwest China

AbstractThe impact of climate change on the variability of local discharge was investigated in a glacierized high mountain catchment located in the source area of the Ürümqi river, northwest China. We used past climate records to drive a hydrological model to simulate the discharge from 2000 to 2008. The model was then used to project future discharge variations for the period 2041–60, based on a regionally downscaled climate-change scenario combined with three stages of glacier coverage (i.e. compared to the glacier coverage in 2008): unchanged glacier size (100% glacierized), recession of half the glacier area (50% glacierized) and complete disappearance of glaciers (0% glacierized). In each scenario, snowmelt will begin half a month earlier and the discharge will increase in May. For the 100% glacierized scenario, the discharge will increase by 66 ± 35% in a smaller (3.34 km2) and more glaciated (50%) catchment and 33 ± 20% in a larger (28.90 km2) and proportionally less glaciated (18%) catchment. If the glacier area reduces by half, the discharge will decrease by 8 ± 5% and 9 ± 6%, respectively. Once the glacier disappears, the discharge will decrease by 58 ± 20% and 40 ± 13%, respectively. Together, the results indicate that a warming climate and the resulting glacier shrinkage will cause significant changes in the volume and timing of runoff.

The disappearance of glaciers in the Tien Shan Mountains in Central Asia at the end of Pleistocene

Glaciers in Central Asia are among the largest ice masses in the Eurasian continent and have supplied vital water to local inhabitants for thousands of years. The glaciers in this region are generally believed to be remnants of the last deglaciation, however, glacier variability in the central Asian mountains since the Last Glacial Maximum (LGM) has not been well documented. Here, we report an 86.87 m-deep ice core record drilled on an ice cap in the Tien Shan Mountains of Central Asia. Radiocarbon dating of organic soil from the bottom of the ice-core borehole showed that the age of the soil was 12,656 – 12,434 cal years before present, coincident with the beginning of the Younger Dryas cold period (YD). This result indicates that the ice cap did not exist in the Bølling-Allerød period (BA), which was the warm period before the YD, and that the BA climate was significantly warmer than at present. It also indicates that the ice cap has never entirely disappeared in any warm periods throughout the Holocene. We estimated that during the BA its extent was 43% or less of the present glacier coverage in the mountains. Our results suggest that this region at the end of Pleistocene was considerably warmer than at present, and that most of the present glaciers in this region are not relics of the Last Glacial period, but are composed of ice formed during the YD and Holocene.

Feedbacks and mechanisms affecting the global sensitivity of glaciers to climate change

Abstract. Mass loss by glaciers has been an important contributor to sea level rise in the past, and is projected to contribute a substantial fraction of total sea level rise during the 21st century. Here, we use a model of the world's glaciers to quantify equilibrium sensitivities of global glacier mass to climate change, and to investigate the role of changes in glacier hypsometry for long-term mass changes. We find that 21st century glacier-mass loss is largely governed by the glacier's response to 20th century climate change. This limits the influence of 21st century climate change on glacier-mass loss, and explains why there are relatively small differences in glacier-mass loss under greatly different scenarios of climate change. The projected future changes in both temperature and precipitation experienced by glaciers are amplified relative to the global average. The projected increase in precipitation partly compensates for the mass loss caused by warming, but this compensation is negligible at higher temperature anomalies since an increasing fraction of precipitation at the glacier sites is liquid. Loss of low-lying glacier area, and more importantly, eventual complete disappearance of glaciers, strongly limit the projected sea level contribution from glaciers in coming centuries. The adjustment of glacier hypsometry to changes in the forcing strongly reduces the rates of global glacier-mass loss caused by changes in global mean temperature compared to rates of mass loss when hypsometric changes are neglected. This result is a second reason for the relatively weak dependence of glacier-mass loss on future climate scenario, and helps explain why glacier-mass loss in the first half of the 20th century was of the same order of magnitude as in the second half of the 20th century, even though the rate of warming was considerably smaller.

The History and Disappearance of Glaciers in Venezuela

La desaparición de los glaciares en Venezuela es narrada cronológicamente a través de una extensa recopilación y análisis de la literatura científica, mapas y fotografías históricas. Un análisis de datos climáticos y mapeo GPS en 2009 y 2011 proporcionan el contexto moderno del único remanente glacial presente. La recesión glacial venezolana durante el siglo veinte es similar a otras partes de América del Sur y en consonancia con los efectos previstos del cambio climático regional. Hoy en día, solo un glaciar con una superficie de aproximadamente 0.1 km 2 queda en los Andes venezolanos cerca la ciudad de Mérida, este probablemente desaparecerá en la presente década. Sin embargo, la falta de datos sobre el balance de masa de este glaciar limita nuestra capacidad de apreciar la historia de los glaciares en Venezuela y un programa de monitoreo integral se necesita con urgencia antes de que Venezuela se convierta en un país totalmente libre de hielo glacial.

Biodiversity under threat in glacier-fed river systems

In many regions climate change is reducing the glacial meltwater contribution to river flow, but the effect of these changes on specialized glacier-fed river communities is poorly quantified. Now research demonstrates quantitatively not only the vulnerability of local biodiversity hotspots but also that the number of species lost is likely to be much higher than the few specialist species found only in glacier-fed rivers. Freshwater biodiversity is under threat across the globe1, with climate change being a significant contributor2,3. One impact of climate change is the rapid shrinking of glaciers4, resulting in a reduction in glacial meltwater contribution to river flow in many glacierized catchments5,6. These changes potentially affect the biodiversity of specialized glacier-fed river communities7. Perhaps surprisingly then, although freshwater biodiversity is a major conservation priority3, the effects of shrinkage and disappearance of glaciers on river biodiversity have hitherto been poorly quantified. Here we focus on macroinvertebrates (mainly insect larvae) and demonstrate that local (α) and regional (γ) diversity, as well as turnover among reaches (β-diversity), will be consistently reduced by the shrinkage of glaciers. We show that 11–38% of the regional species pools, including endemics, can be expected to be lost following complete disappearance of glaciers in a catchment, and steady shrinkage is likely to reduce taxon turnover in proglacial river systems and local richness at downstream reaches where glacial cover in the catchment is less than 5–30%. Our analysis demonstrates not only the vulnerability of local biodiversity hotspots but also that extinction will probably greatly exceed the few known endemic species in glacier-fed rivers.

Evaluating the effect of snow and ice melt in an Alpine headwater catchment and further downstream in the River Rhine

The runoff regime of glacierized headwater catchments in the Alps is essentially characterized by snow and ice melt. High Alpine drainage basins influence distant downstream catchments of the Rhine River basin. In particular, during the summer months, low-flow conditions are probable with strongly reduced snow and ice melt under climate change conditions. This study attempts to quantify present and future contributions from snow and ice melt to summer runoff at different spatial scales. For the small Silvretta catchment (103 km2) in the Swiss Alps, with a glacierization of 7%, the HBV model and the glacio-hydrological model GERM are applied for calculating future runoff based on different regional climate scenarios. We evaluate the importance of snow and ice melt in the runoff regime. Comparison of the models indicates that the HBV model strongly overestimates the future contribution of glacier melt to runoff, as glaciers are considered as static components. Furthermore, we provide estimates of the current meltwater contribution of glaciers for several catchments downstream on the River Rhine during the month of August. Snow and ice melt processes have a significant direct impact on summer runoff, not only for high mountain catchments, but also for large transboundary basins. A future shift in the hydrological regime and the disappearance of glaciers might favour low-flow conditions during summer along the Rhine. Citation Junghans, N., Cullmann, J. & Huss, M. (2011) Evaluating the effect of snow and ice melt in an Alpine headwater catchment and further downstream in the River Rhine. Hydrol. Sci. J. 56(6), 981–993.

Acquisition of the 3D boundary of the Triglav glacier from archived non‐metric panoramic images

AbstractA panoramic, non‐metric, Horizont camera has been used for regular, monthly, close‐range photography of the rapidly retreating Triglav glacier in Slovenia since 1976. The unfavourable geometry of the convergent images taken from the two camera stations has made any direct stereoscopic observation and recording impossible. The aim of this research was to define the most useful method for acquiring 3D data from these panoramic, convergent images. The Horizont camera was calibrated and three methods were then tested: the generation of pseudo‐orthophotographs, the application of 2D clinometry and the interactive orientation of a detailed digital elevation model (DEM) on the images. The third turned out to be the only method suitable for determining the boundary of the Triglav glacier.The interactive orientation of a detailed DEM on the Horizont images is described in detail. The 3D glacier boundary can be acquired from individual Horizont images (camera stations A and B) enabling the computation of the glacier’s area and theoretical volume. By repeating the glacier boundary acquisition for different orientation parameters, the standard deviations of the glacier area and theoretical volume were computed. Because of the more precise average area and volume measurements achieved with the camera station B images, only these were chosen for the glacier disappearance study. Every third year between 1976 and 2005 the Horizont images were used to compute the changes in the area and volume of the glacier. The glacier area was found to have reduced to 8% of its earlier size, from 15 ha in 1976 to 1·2 ha in 2000. However, owing to harsher than average winters since then the decline in the glacier area was found to have slowed in the past decade (2000 to 2009). The glacier’s theoretical volume decreased roughly exponentially from 1976 to 2005.

Climate: When the ice melts

Deep in the Himalayas, the disappearance of glaciers is threatening the kingdom of Bhutan. Anjali Nayar trekked through the mountains to see how the country is adapting to a warming world.

Disappearance of an Alpine glacier over the 21st Century simulated from modeling its future surface mass balance

A spatially-distributed snow/ice model is used to simulate the surface mass balance of the Saint Sorlin Glacier (French Alps) over the 1981–2004 period. The modeled mass balance globally reproduces field data except over places where, because of the scarcity of measurements, small-scale features as proposed by the model are smoothed out by the data interpolation. Both measured and simulated mass balance fields are then used to force a 2-D ice flow model and comparison of respective results show similar large-scale glacier flow dynamics. On the other hand, at a smaller scale, the present-day ice distribution computed from the modeled mass balance field sometimes deviates from that obtained with the interpolated field mass balance. It particularly offers a better match to observations by succeeding in reproducing a specific deglaciation pattern in the upper part of the glacier. These preliminary results led us to consider the possibility of substituting modeled mass balance series to measured ones, especially when modeling the future of the glacier. This latter approach is thus applied to simulate the glacier response under the IPCC SRESB1 scenario. Results show a rapid decay leading to a total disappearance of the glacier by the year 2070.

Deglacial Control on Sedimentation and Basin Evolution of Permo-Carboniferous Talchir Formation, Talchir Gondwana Basin, Orissa, India

The Permo-Carboniferous Talchir Formation in the southeastern part of the Talchir basin is represented by about 260 m thick clastic succession resting on the Precambrian basement rocks of the Eastern Ghats Group. The succession is tentatively subdivided into four lithostratigraphic units, namely A-I, A-II, B and C from base to top. Unit A-I comprises mud-matrixed, very poorly sorted diamictites and interbedded thin sandstone and mudstone yielding dropstones. They reveal deposition in a proglacial lake environment in which ice rafting and suspension sedimentation, as well as meltwater-underflow processes, produced variety of facies. The succession of unit A-II is dominated by pebble to boulder conglomerates and sandstones. They were deposited mostly from various kinds of high-energy sediment gravity flows, both subaerial and subaqueous, and formed steep-faced fan-delta on the margin of the basin. Unit B demonstrates turbidite sedimentation in lake-margin slope and base-of-slope environments, in which a sublacustrine channel-fan system developed. The lake-margin slope was dissected by channels which were accompanied by overbank and levee deposits. Sediments delivered from the mouth of a channel were deposited at the base-of-slope, forming a fan lobe which prograded onto the lake basin floor. Unit C dominantly consists of mudstone with intercalations of siltstone and sandstone and forms a large-scale coarsening-upward deltaic sequence eventually covered by the fluvial deposits of the Karharbari Formation. Following the glacially influenced sedimentation, the Talchir succession shows a vertical facies progression suggesting gradual deepening of the lake basin and eventual filling up of it due to rapid delta progradation. Such a succession represents deglacial control on basin evolution during the Talchir time. In the initial stage of glacial recession, collapse of a glacier and failure of montane glacial lakes frequently occurred and gave rise to generation of a highly sediment-laden debris flow and a catastrophic flood, which brought abundant coarse clastics into the lake and built a fan-delta on the basin margin. The continued recession and disappearance of glacier resulted in abundant supply of ice-melt water into the graben as well as eustatic sea-level rise, being the cause of the rise in lake-level. Subsequent rapid delta progradation and eventual filling-up of the lake basin suggest rapid lake-level fall after deepening of lake basin. It was possibly caused by the regional uplift due to post-glacial isostatic rebound. Rapid draining of lake water through the graben gave rise to the establishment of an axial drainage system which rapidly filled the lake basin in form of an axially fed delta.

Effect of glacier loading/deloading on volcanism: postglacial volcanic production rate of the Dyngjufj�ll area, central Iceland

Tephrochronological dating of postglacial volcanism in the Dyngjufjoll volcanic complex, a major spreading center in the Icelandic Rift Zone, indicates a high production rate in the millennia following deglaciation as compared to the present low productivity. The visible and implied evidence indicates that lava production in the period 10 000–4500 bp was at least 20 to 30 times higher than that in the period after 2900 bp but the results are biased towards lower values for lava volumes during the earlier age periods since multiple lava layers are buried beneath younger flows. The higher production rate during the earlier period coincides with the disappearance of glaciers of the last glaciation. Decreasing lithostatic pressure as the glacier melts and vigorous crustal movements caused by rapid isostatic rebound may trigger intense volcanism until a new pressure equilibrium has been established.