scholarly journals New glacier evidence for ice-free summits during the life of the Tyrolean Iceman

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Pascal Bohleber ◽  
Margit Schwikowski ◽  
Martin Stocker-Waldhuber ◽  
Ling Fang ◽  
Andrea Fischer
Keyword(s):  
Elevation Gradient ◽  
Ice Age ◽  
Detailed Knowledge ◽  
New Approach ◽  
Radiocarbon Age ◽  
Alpine Glaciers ◽  
The Alps ◽  
Tyrolean Iceman ◽  
High Elevations ◽  
Age Constraints

AbstractDetailed knowledge of Holocene climate and glaciers dynamics is essential for sustainable development in warming mountain regions. Yet information about Holocene glacier coverage in the Alps before the Little Ice Age stems mostly from studying advances of glacier tongues at lower elevations. Here we present a new approach to reconstructing past glacier low stands and ice-free conditions by assessing and dating the oldest ice preserved at high elevations. A previously unexplored ice dome at Weißseespitze summit (3500 m), near where the “Tyrolean Iceman” was found, offers almost ideal conditions for preserving the original ice formed at the site. The glaciological settings and state-of-the-art micro-radiocarbon age constraints indicate that the summit has been glaciated for about 5900 years. In combination with known maximum ages of other high Alpine glaciers, we present evidence for an elevation gradient of neoglaciation onset. It reveals that in the Alps only the highest elevation sites remained ice-covered throughout the Holocene. Just before the life of the Iceman, high Alpine summits were emerging from nearly ice-free conditions, during the start of a Mid-Holocene neoglaciation. We demonstrate that, under specific circumstances, the old ice at the base of high Alpine glaciers is a sensitive archive of glacier change. However, under current melt rates the archive at Weißseespitze and at similar locations will be lost within the next two decades.

Climate Change and Glacier Reaction in the European Alps

2021 ◽  
Author(s):  
Wolfgang Schöner
Keyword(s):  
Mass Balance ◽  
Ice Age ◽  
Glacier Mass Balance ◽  
European Alps ◽  
Mass Balances ◽  
Changing Climate ◽  
Alpine Glaciers ◽  
The Alps ◽  
Glacier Flow ◽  
The Relationship

Glaciers are probably the most obvious features of Earth’s changing climate. They enable one to see the effects of a warming or a cooling of the atmosphere by landscape changes on time scales short enough to be perceived or recognized by humans. However, the relationship between a retreating and advancing glacier and the climate is not linear, as glacier flow can filter the direct signal of the climate. Thus, glaciers can advance during periods of warming or, vice versa, retreat during periods of cooling. In fact, it is the mass change of the glacier (i.e., the mass balance) that directly links the glacier reaction to an atmospheric signal. The mechanism-based understanding of the relationship between the changing climate and glacier reaction received important and significant momentum from the science of the Alpine region. This strong momentum from the Alps has to do with the well-established science tradition in Europe in the 19th and beginning of the 20th century, which resulted in a series of important inventions to measure climate and glacier properties. Even at that time, knowledge was gained that is still valid in the early 21st century (e.g., the climate is changing and fluctuating; glacier changes are caused by changing climate; and the ice age was the result of shifting climate). Above all others, Albrecht Penck and Eduard Brückner were the key scientists in this blossoming era of glacier climatology. Interest in a better understanding of the relationship of climate to glaciers was not only driven by curiosity, but also by several impacts of glaciers on human life in the Alps. Investigations of climate–glacier relationships in the Alps began with the expiration of the Little Ice Age (LIA) period when glaciers were particularly large but began to retreat significantly. Observations of post-LIA glacier front positions showed a sharp decline after their maximum extent in about 1850 until the turn of the 19th to 20th centuries, when they began to grow and advance again. They were also forming a prominent moraine around 1920, which was, however, far behind the 1850 extent. Interestingly, climate time series of the post LIA period show a general long-term cooling of summer temperatures and several decades of precipitation deficit in the second half of the 19th century. Thus, the retreat forced by climate changes cannot be simply explained by increasing air temperatures, though calibrated glacier mass balance models are able to simulate this period quite well. Additional effects related to the albedo could be a source for a better understanding. From 1920 onward, the climate moved into a period of warm and high-sunshine summers, which peaked in the 1940s until 1950. Glaciers started again to melt strongly and related discharges of pro-glacial rivers were exceptionally high during this period as glaciers were still quite large and the available energy for melt from radiation was enhanced. With the shift of the Atlantic meridional overturning (AMO), which is an important driver of European climate, into a negative mode in the 1960s, the mass balances of Alpine glaciers experienced more and more positive mass balance years. This finally resulted in a period of advancing glaciers and the development of frontal moraines around 1980 for a large number of glaciers. Thereafter, from 1980 onward, Alpine glaciers moved into an era of continuous negative mass balances and particularly strong retreat. The anthropogenic forcing from greenhouse gases together with global brightening and the increase of anticyclonic weather types in summer moved the climate and thus the mass balances of glaciers into a state far away from equilibrium. Given available scenarios of future climate, this retreat will continue and, even under the optimistic RCP2.6 scenario, glaciers (as derived from model simulations for the future) will not return to an equilibrium mass balance before the end of the 21st century. According to a glacier inventory for the European Alps from Landsat Thematic Mapper scenes of 2003, published by Paul and coworkers in 2011, the total surface of all glaciers and ice patches in the European Alps in 2003 was 2,056 km² (50% in Switzerland, 19% in Italy, 18% in Austria, 13% in France, and <1% in Germany). Generally, the reaction of Alpine glaciers to climate perturbations is rather well understood. For the glaciers of the Alps, important processes of glacier changes are related to the surface energy balance during the ablation season when radiation is the primary source of energy for snow and ice melt. Other ablation processes, such as sublimation and internal and basal ablation, are small compared to surface melt. This specificity enables the use of simple temperature-based models to simulate the mass balance of glaciers sufficiently well. Besides atmospheric forcing of glacier mass balance, glacier flow (which is related to englacial temperature distribution) plays a role, in particular, for observed front position changes of glaciers. Glaciers are continuously adapting their size to the climate, which could work much faster for smaller glaciers compared to large valley glaciers of the Alps having a response time of about 100 years.

scholarly journals 19th century glacier retreat in the Alps preceded the emergence of industrial black carbon deposition on high-alpine glaciers

2018 ◽  
Vol 12 (10) ◽  
pp. 3311-3331 ◽  
Author(s):  
Michael Sigl ◽  
Nerilie J. Abram ◽  
Jacopo Gabrieli ◽  
Theo M. Jenk ◽  
Dimitri Osmont ◽  
...  
Keyword(s):  
Black Carbon ◽  
19Th Century ◽  
Little Ice Age ◽  
Ice Core ◽  
Ice Cores ◽  
Ambient Air ◽  
Radiative Properties ◽  
Ice Age ◽  
Alpine Glaciers ◽  
The Alps

Abstract. Light absorbing aerosols in the atmosphere and cryosphere play an important role in the climate system. Their presence in ambient air and snow changes the radiative properties of these systems, thus contributing to increased atmospheric warming and snowmelt. High spatio-temporal variability of aerosol concentrations and a shortage of long-term observations contribute to large uncertainties in properly assigning the climate effects of aerosols through time. Starting around AD 1860, many glaciers in the European Alps began to retreat from their maximum mid-19th century terminus positions, thereby visualizing the end of the Little Ice Age in Europe. Radiative forcing by increasing deposition of industrial black carbon to snow has been suggested as the main driver of the abrupt glacier retreats in the Alps. The basis for this hypothesis was model simulations using elemental carbon concentrations at low temporal resolution from two ice cores in the Alps. Here we present sub-annually resolved concentration records of refractory black carbon (rBC; using soot photometry) as well as distinctive tracers for mineral dust, biomass burning and industrial pollution from the Colle Gnifetti ice core in the Alps from AD 1741 to 2015. These records allow precise assessment of a potential relation between the timing of observed acceleration of glacier melt in the mid-19th century with an increase of rBC deposition on the glacier caused by the industrialization of Western Europe. Our study reveals that in AD 1875, the time when rBC ice-core concentrations started to significantly increase, the majority of Alpine glaciers had already experienced more than 80 % of their total 19th century length reduction, casting doubt on a leading role for soot in terminating of the Little Ice Age. Attribution of glacial retreat requires expansion of the spatial network and sampling density of high alpine ice cores to balance potential biasing effects arising from transport, deposition, and snow conservation in individual ice-core records.

scholarly journals Radiocarbon Age Constraints on Rates of Advance and Retreat of the Puget Lobe of the Cordilleran Ice Sheet during the Last Glaciation

1998 ◽  
Vol 50 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Stephen C. Porter ◽  
Terry W. Swanson
Keyword(s):  
Average Rate ◽  
Distance Curve ◽  
Radiocarbon Dates ◽  
Radiocarbon Age ◽  
Glacier Terminus ◽  
Ice Retreat ◽  
Time Distance ◽  
Cordilleran Ice Sheet ◽  
Glacier Advance ◽  
Age Constraints

Calibrated radiocarbon dates of organic matter below and above till of the last (Fraser) glaciation provide limiting ages that constrain the chronology and duration of the last advance–retreat cycle of the Puget Lobe in the central and southeastern Puget Lowland. Seven dates for wood near the top of a thick proglacial delta have a weighted mean age of 17,420 ± 90 cal yr B.P., which is the closest limiting age for arrival of the glacier near the latitude of Seattle. A time–distance curve constructed along a flowline extending south from southwestern British Columbia to the central Puget Lowland implies an average glacier advance rate of ca. 135 m/yr. The glacier terminus reached its southernmost limit ca. 16,950 yr ago and likely remained there for ca. 100 yr. In the vicinity of Seattle, where the glacier reached a maximum thickness of 1000 m, ice covered the landscape for ca. 1020 yr. Postglacial dates constraining the timing of ice retreat in the central lowland are as old as 16,420 cal yr B.P. and show that the terminus had retreated to the northern limit of the lowland within three to four centuries after the glacial maximum. The average rate of retreat was about twice the rate of advance and was enhanced by rapid calving recession along flowline sectors where the glacier front crossed deep proglacial lakes.

scholarly journals Bodengeographische Beobachtungen zur pleistozänen und holozänen Vergletscherung des Westlichen Tienshan (Usbekistan)

1996 ◽  
Vol 46 (1) ◽  
pp. 144-151
Author(s):  
Wolfgang Zech ◽  
Rupert Bäumler ◽  
Oksana Savoskul ◽  
Anatoli Ni ◽  
Maxim Petrov
Keyword(s):  
Little Ice Age ◽  
Late Glacial ◽  
Ice Age ◽  
Lower Side ◽  
Glacial Ice ◽  
Middle Holocene ◽  
Glacial Origin ◽  
Weathered Soils ◽  
Recent Origin ◽  
The Alps

Abstract. Soil geographic studies were carried out in the Oigaing valley between Ugamsky and Pskemsky range NE of Tashkent (W-Tienshan, Republic of Uzbekistan) with special regard to the Pleistocene and Holocene glaciation. Clear end moraines of the last main glaciation are preserved at the junction of Maidan and Oigaing river at 1500-1600 m a.s.l. They show intensively weathered soils with a depth of more than 80 cm. Similar deposits ol presumably Pleistocene or late glacial origin are also located upvalley at the embouchure of numerous side valleys (Beschtor, Tekesch, Aütor) into the main valley of Oigaing. All side valleys are characterized by late glacial ground and end moraines in 2500-2700 m a.s.l. showing intensively weathered brown colored soils of 30-40 cm depth. Further moraines of Holocene or recent origin are located approach of the recent glaciers which descend to 3000-3200 m. They show shallow, initial soils, and presumably correspond with glacial advances during the so-called "Little Ice Age" with a maximum advance at about 1850 in the Alps, and in the middle Holocene at about 2000 or 4000 a BP. Highly weathered, and rubefied interglacial soils developed from old Quaternary gravel are preserved above high glacial ice marginal grounds of the last main glaciation (>2850 m a.s.l.) in the lower side valley of the Barkrak river. In the upper valley huge drift could be shown above the ice marginal grounds, but without typical forms of morainic deposits. They give evidence for older glaciations with a greater extent compared with the last main glaciation. However, no corresponding moraines are present in the working area.

scholarly journals New Approach in COD Fractionation Methods

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1484 ◽  
Author(s):  
Ewelina Płuciennik-Koropczuk ◽  
Sylwia Myszograj
Keyword(s):  
Degradation Rate ◽  
Oxygen Demand ◽  
Quality Parameters ◽  
Treated Wastewater ◽  
Detailed Knowledge ◽  
New Approach ◽  
High Compliance ◽  
The Difference ◽  
Biochemical Degradation ◽  
Raw Wastewater

Conventional quality parameters such as Chemical Oxygen Demand (COD) or Biochemical Oxygen Demand (BOD) give information about the quantity of organic matter present in wastewater, but do not give a clear indication of the biodegradability of the pollutants flowing in the WWTP. Detailed knowledge can be obtained by dividing the total COD into fractions. Fractionation and balancing of COD can be determined in various ways and with varying accuracy. Good wastewater characteristics are obtained on the basis of COD fractionation in accordance with ATV-A 131 guidelines, especially when the wastewater characteristics are in high compliance with the assumptions of the method. The article proposes a modification of the ATV-A131 method that increases the accuracy of determining the COD fraction. In order to reduce errors in the calculation of COD fractions, the value of fraction XS was calculated on the basis of the biochemical degradation rate determined in studies (k) for raw wastewater, whereas the SI fraction was calculated from the difference between SCOD and BODTot of filtered treated wastewater. BODTot of the treated wastewater was calculated taking into account the rate of biochemical degradation determined in the studies (k) for treated wastewater. The shares of individual COD fractions in raw wastewater calculated on the basis of the standard and modified procedure differed by approx. 10% in the case of suspension fractions. Modification of the methodology to determine the COD of the treated wastewater SS fraction significantly influenced the contents of all fractions in treated wastewater.

scholarly journals Glaciomarine sequence stratigraphy in the Mississippian Río Blanco Basin, Argentina, southwestern Gondwana. Basin analysis and palaeoclimatic implications for the Late Paleozoic Ice Age during the Tournaisian.

2020 ◽  
Vol 177 (6) ◽  
pp. 1107-1128 ◽  
Author(s):  
Miguel Ezpeleta ◽  
Juan José Rustán ◽  
Diego Balseiro ◽  
Federico Miguel Dávila ◽  
Juan Andrés Dahlquist ◽  
...  
Keyword(s):  
Compositional Analysis ◽  
Ice Age ◽  
Late Paleozoic ◽  
Provenance Analysis ◽  
Glacial Ice ◽  
Content Type ◽  
Late Paleozoic Ice Age ◽  
Glacial Stage ◽  
Supplementary Material ◽  
Age Constraints

The Late Paleozoic Ice Age (LPIA) has been well recorded in the uppermost Mississippian–Pennsylvanian of Gondwana. Nevertheless, little is known about the temporal and geographic dynamics, particularly during the early Mississippian. We report on exceptional Tournaisian glaciomarine stratigraphic sections from central Argentina (Río Blanco Basin). Encompassing c. 1400 m, these successions contain conspicuous glacigenic strata with age constraints provided by palaeontological data and U/Pb detrital zircon age spectra. A variety of marine, glaciomarine and fan-deltaic environments indicate relative sea-level variations mainly associated with tectonism and repetitive cycles of glacial activity. Provenance analysis indicates a source from the Sierras Pampeanas basement located to the east. Fifteen sequences were grouped into three depositional models: (1) Transgressive Systems Tracts (TST) to Highstand Systems Tracts (HST) sequences unaffected by glacial ice; (2) Lowstand Systems Tracts (LST) to TST and then to HST with glacial influence; and (3) non-glacial Falling-Stage Systems Tracts (FSST) to TST and HST. The glacial evidence indicates that the oldest Mississippian glacial stage of the LPIA in southwestern Gondwana is constrained to the middle Tournaisian. In contrast with previous descriptions of Gondwanan coeval glacial records, our sequence analysis confirms complex hierarchical climate variability, rather than a single episode of ice advance and retreat.Supplementary material: Detailed stratigraphic sections, palaeocurrents and compositional analysis and U/Pb detrital Zr methodology and data are available at: https://doi.org/10.6084/m9.figshare.c.5011424

New radiocarbon age constraints for the 120 km-long Toomba flow, north Queensland, Australia

2018 ◽  
Vol 66 (1) ◽  
pp. 71-79
Author(s):  
A. K. Mishra ◽  
C. Placzek ◽  
C. Wurster ◽  
P. W. Whitehead
Keyword(s):  
Radiocarbon Age ◽  
Age Constraints

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

&lt;p&gt;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 (Ram&amp;#237;rez et al., 2001). However, there is scarce knowledge in Mexico about the glacier changes since the LIA. The reconstructions are limited to the Iztacc&amp;#237;hualt volcano where Schneider et al. (2008) established a glacier retreat of 95 %.&lt;/p&gt;&lt;p&gt;Here, we reconstruct the glacier evolution since the LIA to CE 2015 of the Mexican highest ice-capped volcano: Pico de Orizaba (19&amp;#176; 01&amp;#180; N, 97&amp;#176; 16&amp;#180;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 Iztacc&amp;#237;hualt 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 V&amp;#225;zquez-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&lt;sup&gt;2&lt;/sup&gt;) and 2015 (0.67 km&lt;sup&gt;2&lt;/sup&gt;), being a drastic glacier loss in agreement with the Bolivian Andes and Iztacc&amp;#237;hualt. Therefore, mexican glaciers have experienced the major shrunk since LIA that implies a highly sensitive reaction to global warming.&lt;/p&gt;&lt;p&gt;This research was supported by the Project UNAM-DGAPA-PAPIIT grant IA105318.&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Palacios, D., V&amp;#225;zquez-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.&lt;/p&gt;&lt;p&gt;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.&lt;/p&gt;&lt;p&gt;Ram&amp;#237;rez, E., Francou, B., Ribstein, P., Descloitres, M., Gu&amp;#233;rin, 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&amp;#176; S). Journal of Glaciology 47 (157), 187-194.&lt;/p&gt;&lt;p&gt;Rico I., Izagirre E., Serrano E., L&amp;#243;pez-Moreno J.I., 2016. Current glacier area in the Pyrenees&amp;#160;: an updated assessment 2016. Pirineos 172, doi: http://dx.doi.org/10.3989/Pirineos.2017.172004.&lt;/p&gt;&lt;p&gt;Schneider, D., Delgado-Granados, H., Huggel, C., K&amp;#228;&amp;#228;b, A. 2008. Assessing lahars from ice-capped volcanoes using ASTER satellite data, the SRTM DTM and two different flow models: case study on Iztacc&amp;#237;huatl (Central Mexico). Natural Hazards and Earth System Sciences 8, 559-571.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals Snow accumulation and ice flow at Dôme du Goûter (4300 m), Mont Blanc, French Alps

1997 ◽  
Vol 43 (145) ◽  
pp. 513-521 ◽  
Author(s):  
C. Vincent ◽  
M. Vallon ◽  
J. F. Pinglot ◽  
M. Funk ◽  
L. Reynaud
Keyword(s):  
Mass Balance ◽  
Flow Model ◽  
Snow Accumulation ◽  
Ice Age ◽  
Seasonal Patterns ◽  
Ice Flow ◽  
The Alps ◽  
Radioactivity Measurements ◽  
Simple Flow

AbstractGlaciological experiments have been carried out at Dôme du Goûter (4300 m a.s.l.), Mont Blanc, in order to understand the flow of firn/ice in this high-altitude Alpine glacierized area. Accumulation measurements from stakes show a very strong spatial variability and an unusual feature of mass-balance fluctuations for the Alps, i.e. the snow accumulation does not show any seasonal patterns. Measured vertical velocities which should match with long-term mean mass balance are consistent with observed accumulations. Therefore, the measurement of vertical velocities seems a good way of quickly obtaining reliable mean accumulation values for several decades in such a region.A simple flow model can be used to determine the main flowlines of the glacier and to propose snow/ice age of core samples from the two boreholes drilled down tο the bedrock in June 1994. These results coincide with radioactivity measurements made to identify the well-known radioactive snow layers of 1963 and 1986. We can hope to obtain ice samples 55–60 years old about 20 or 30 m above the bedrock (110 m deep). Below, the deformation of the ice layers is loo great to be dated accurately.

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