A new ice core from the Eastern Summit of Mt. Elbrus, Caucasus, Russia

2021 ◽  
Author(s):  
Stanislav Kutuzov ◽  
Vladimir Mikhalenko ◽  
Ivan Lavrantiev ◽  
Pavel Toropov ◽  
Diana Vladimirova ◽  
...  
Keyword(s):  
National Park ◽  
Ice Core ◽  
Ice Thickness ◽  
Synoptic Scale ◽  
Russian Science ◽  
Glacier Surface ◽  
Borehole Temperature ◽  
Fumarole Field ◽  
Seasonal Snow Cover ◽  
Very High

<p>Meteorological regime and glacier surface heat balance, GPR measurements of the ice thickness and seasonal snow cover were investigated in the crater of the Eastern Summit of Mt. Elbrus In the period from 18 to 30 August 2020 at 560 m a.s.l. On the base of preliminary data analysis, the predominance of fluctuations in the synoptic scale over the diurnal ones was revealed; high values of the average and maximum wind speed associated with the influence of jet currents and with the effects of leeward storms were identified; extremely high temporal variability of relative humidity and its very high deficit in cloudless conditions, which contributes to intensive evaporation and sublimation from the snow surface, were explored. The maximum ice thickness in the crater reaches 100 m, with an average of 45 m. A new 96.01 m ice core from glacier surface to bedrock has been recovered. The drilling speed varied from 11 to 1 m / h, decreasing on average with depth from 4.5 to 4.0 m / h. The thickness of the snow-firn strata is about 20 m, which is three times less than on the Western Plateau. The borehole temperature was measured. The temperature on the glacier bedrock was -0.6 °С. The calculated heat flux was 0.39 W/m2. Air sampling was carried out in the crater of the Eastern Summit of Elbrus and on the Garabashi glacier. The repeated measurement of the soil temperature in the fumarole field on the Elbrus Eastern Summit outer crater rim suggests that the temperature regime is stable.</p><p>The research was carried out on the territory of the Elbrus National Park with the financial support of the Russian Science Foundation (project 17-17-01270).</p>

Glaciological setting and subglacial conditions at Little Dome C, the future site for Beyond Epica – Oldest Ice Core

2020 ◽  
Author(s):  
Julius Rix ◽  
Robert Mulvaney ◽  
Carlos Martin ◽  
Catherine Ritz ◽  
Massimo Frezzotti
Keyword(s):  
Crystal Orientation ◽  
Ice Core ◽  
Low Frequency ◽  
Thermal Conditions ◽  
Ice Thickness ◽  
Strain Rates ◽  
Surface Precipitation ◽  
The Future ◽  
Borehole Temperature ◽  
Basal Melting

<p>Ice domes in the interior of East Antarctica are ideal candidates in the quest for the longest continuous record of climate in polar ice. They are in areas with low surface precipitation, low horizontal advection and large ice thickness. However, the age of the ice near the bottom of the column is very sensitive to subglacial thermal conditions as they can promote basal melting and the loss of the bottommost and oldest ice. Here we report the main findings from a geophysical survey and a shallow, 460m depth, rapid access drilled borehole. We use a low frequency radar, DELORES, to survey the area and detect subglacial melting; a phase sensitive radar, ApRES, to obtain englacial vertical strain-rates and crystal orientation fabrics in selected sites; and, at the drilling site, borehole temperature and water isotope data in the top 460m. Our main findings are: 1) The subglacial topography is characterized by topographic highs criss-crossed by deep valley troughs with typically 0.5-1km difference in height. There is evidence of subglacial melting in the troughs. However the ice stratigaphy, that we survey in detail with DELORES system with 500m grid, drapes over the rough topography and the topographic highs are presently melt-free. 2) The optical birefringence, observed in ApRES polarimetry, shows two aligned crystal orientation fabrics that are typical for glacial periods. This indicate uniform ice-flow conditions during, at least, the last two glacial-interglacial periods and is consistent with the polarimetry from EPICA Dome C. 3) Using the borehole temperature, englacial strain-rates and temperature records from EPICA Dome C we estimate that the geothermal heatflux in the area is 55 +/- 1 mW/m2. Also we find that, due to the delay between basal and surface temperatures, the basal temperature at Little Dome C is currently the coldest and was 0.5 C warmer 80 kyrs ago. We estimate that any topographic high where the ice thickness is below 2810 +/- 10 m was melt-free during the warmest conditions. This information, together with other evidence, lead to choosing the site for the future Beyond Epica – Oldest Ice Core project.</p>

In-situ automatic observations of ice thickness of seas

2012 ◽  
Vol 19 (3) ◽  
pp. 583-592 ◽  
Author(s):  
Yinke Dou ◽  
Xiaomin Chang
Keyword(s):  
Sea Ice ◽  
New Technologies ◽  
Capacitive Sensor ◽  
Automatic Monitoring ◽  
Ice Thickness ◽  
In Situ Observation ◽  
Glacier Surface ◽  
Sea Ice Thickness ◽  
Surface Ice

Abstract Ice thickness is one of the most critical physical indicators in the ice science and engineering. It is therefore very necessary to develop in-situ automatic observation technologies of ice thickness. This paper proposes the principle of three new technologies of in-situ automatic observations of sea ice thickness and provides the findings of laboratory applications. The results show that the in-situ observation accuracy of the monitor apparatus based on the Magnetostrictive Delay Line (MDL) principle can reach ±2 mm, which has solved the “bottleneck” problem of restricting the fine development of a sea ice thermodynamic model, and the resistance accuracy of monitor apparatus with temperature gradient can reach the centimeter level and research the ice and snow substance balance by automatically measuring the glacier surface ice and snow change. The measurement accuracy of the capacitive sensor for ice thickness can also reach ±4 mm and the capacitive sensor is of the potential for automatic monitoring the water level under the ice and the ice formation and development process in water. Such three new technologies can meet different needs of fixed-point ice thickness observation and realize the simultaneous measurement in order to accurately judge the ice thickness.

scholarly journals Short-term Variations in Strain and Surface Tilt on Storglaciären, Kebnekaise, Northern Sweden

1989 ◽  
Vol 35 (120) ◽  
pp. 201-208 ◽  
Author(s):  
Peter Jansson ◽  
Roger LeB. Hooke
Keyword(s):  
Water Pressure ◽  
High Water ◽  
Ice Thickness ◽  
Gradual Change ◽  
Short Term ◽  
Glacier Surface ◽  
Vertical Movements ◽  
Bed Topography ◽  
The Waves ◽  
Local Uplift

AbstractTiltmeters that can detect changes in slope of a glacier surface as small as 0.1 μ rad have been used on Storglaciären. The records obtained to date have been from the upper part of the ablation area, where the bed of the glacier is overdeepened. A total of 82 d of records has been obtained for various time periods between early June and early September.There is generally a gradual change in inclination of the glacier surface over periods of several days, but these changes do not appear to be systematic. In particular, they are not consistent with vertical movements of stakes located 2–3 ice thicknesses away from the tiltmeters. This suggests that the tiltmeters are sensing disturbances over areas with diameters comparable to the local ice thickness.Superimposed on these trends are diurnal signals suggesting rises and falls of the surface just up-glacier from the riegel that bounds the overdeepening on its down-glacier end. These may be due to waves of high water pressure originating in a crevassed area near the equilibrium line. If this interpretation is correct, the waves apparently move down-glacier at speeds of 20–60 m h−1and become sufficiently focused, either by the bed topography or by conduit constrictions, to result in local uplift of the surface. Also observed are abrupt tilts towards the glacier center line shortly after the beginning of heavy rainstorms. These appear to be due to longitudinal stretching as the part of the glacier below the riegel accelerates faster than that above. Water entering the glacier by way of a series of crevasses over the riegel is believed to be responsible for this differential acceleration. In June 1987, a dramatic event was registered, probably reflecting the initial summer acceleration of the glacier.

scholarly journals A Synoptic Scale Perspective on Greenland Ice Core δ18O Variability and Related Teleconnection Patterns

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 294
Author(s):  
Norel Rimbu ◽  
Monica Ionita ◽  
Gerrit Lohmann
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Synoptic Scale ◽  
Local Climate ◽  
Rossby Wave Breaking ◽  
Weather Patterns ◽  
Teleconnection Patterns ◽  
Climate Anomalies ◽  
The North ◽  
Oxygen Isotope Ratios

The variability of stable oxygen isotope ratios (δ18O) from Greenland ice cores is commonly linked to changes in local climate and associated teleconnection patterns. In this respect, in this study we investigate ice core δ18O variability from a synoptic scale perspective to assess the potential of such records as proxies for extreme climate variability and associated weather patterns. We show that positive (negative) δ18O anomalies in three southern and central Greenland ice cores are associated with relatively high (low) Rossby Wave Breaking (RWB) activity in the North Atlantic region. Both cyclonic and anticyclonic RWB patterns associated with high δ18O show filaments of strong moisture transport from the Atlantic Ocean towards Greenland. During such events, warm and wet conditions are recorded over southern, western and central part of Greenland. In the same time the cyclonic and anticyclonic RWB patterns show enhanced southward advection of cold polar air masses on their eastern side, leading to extreme cold conditions over Europe. The association between high δ18O winters in Greenland ice cores and extremely cold winters over Europe is partly explained by the modulation of the RWB frequency by the tropical Atlantic sea surface temperature forcing, as shown in recent modeling studies. We argue that δ18O from Greenland ice cores can be used as a proxy for RWB activity in the Atlantic European region and associated extreme weather and climate anomalies.

scholarly journals Describing the Mountainsnails (Oreohelix Sp.) of Grand Teton National Park, Wyoming

2013 ◽  
Vol 36 ◽  
pp. 94-97
Author(s):  
Lusha Tronstad ◽  
Gary Beauvais ◽  
Jeanne Serb ◽  
Kevin Roe
Keyword(s):  
National Park ◽  
National Park Service ◽  
Endangered Species Act ◽  
The State ◽  
Recent Past ◽  
Grand Teton National Park ◽  
Important Group ◽  
Park Service ◽  
Very High ◽  
The U.S

Invertebrates are receiving an increasing amount of conservation attention across North America. Currently, about 40% of the animals listed under the U.S. Endangered Species Act (ESA) are invertebrates (www.NatureServe.org). The National Park Service and other agencies require better information on invertebrate faunas in order to effectively conserve this important group of animals. One way to prioritize invertebrate groups for study is to assess the number of rare taxa within a given genus. In this context, Oreohelix (mountainsnails) are a top priority because the genus is assumed to support a very high percentage of rare and endemic taxa. Additionally, Oreohelix species in Wyoming and surrounding states have been petitioned for ESA listing in the recent past. The diversity of Oreohelix forms in Wyoming is not well-understood, and the current taxonomy may not reflect the true pattern of diversity within the state. Therefore, we are studying both the morphology and genetic structure of Oreohelix in Grand Teton National Park to begin to understand the diversity of mountainsnails in the state. We collected Oreohelix from 4 locations in Grand Teton National Park. Based on shell and internal characteristics, all individuals were identified as O. subrudis. We are currently preparing specimens for DNA sequencing.

scholarly journals Common Birds of Chitwan National Park, Nepal

2017 ◽  
Vol 1 (2) ◽  
pp. 19-26
Author(s):  
Parveen Kumar Jha
Keyword(s):  
Protected Area ◽  
National Park ◽  
Bird Species ◽  
Point Of View ◽  
Central Nepal ◽  
South Central ◽  
Tropical Vegetation ◽  
Chitwan National Park ◽  
Common Birds ◽  
Very High

 This research paper gives checklist of common birds of Chitwan National Park, which is a wild-life protected area in south-central Nepal. It covers tropical and sub-tropical vegetation. It is first protected area and includes 932 sq. km. Common birds observed are about 170 belonging to 48 Avian families during 2013-2014. Present investigator has very minutely observed birds in habitat conditions. Bird species were recognized by very high binocular. Birds were thoroughly studied from point of view of Taxonomy. Machans were also erected for observing birds.

Modern atmospheric monitoring using pollen analysis of ice cores: a case study from the Elbrus Western Plateau, Caucasus, Russia

2021 ◽  
Author(s):  
Vlada Batalova ◽  
Vladimir Mikhalenko ◽  
Stanislav Kutuzov ◽  
Lyudmila Shumilovskikh ◽  
Karim Shukurov
Keyword(s):  
High Altitude ◽  
Pollen Analysis ◽  
Anthropogenic Activities ◽  
Ice Core ◽  
Ice Cores ◽  
Testate Amoebae ◽  
Forest Belt ◽  
Russian Science ◽  
Flexible Tool ◽  
Atmospheric Monitoring

<p>The report highlights the results of first ice-core palynology studies from the Elbrus Western Plateau. The title of the highest point in Europe and the geographical location of Elbrus determine the diversity of natural conditions and, as a result, palynological spectra, which act as markers of seasonal vegetation, climate dynamics, fires and anthropogenic activities in the Mediterranean, southern European Russia, the Middle East, and North Africa.</p><p>The 24-m ice core from the Elbrus Western Plateau collected in 2017 (5115 m a.s.l., 43<sup>о</sup>20′53,9′′ N, 42<sup>о</sup>25′36′′ E) covers the period 2012-2017. Pollen analysis revealed a significant number of biological markers contained in the ice core, including pollen and spores, fungi, algae, testate amoebae, feather barbules, microcharcoal, and black carbon.</p><p>The obtained results show that taxonomic diversity and concentration of biomarkers in the ice core were determined by the seasons of the year and their inherent convective flows. Pollen assemblages are characterized by predominance of native Caucasian plant species. Among them pollen values of Picea forming the high-altitude forest belt in the Western Caucasus significantly exceed pollen frequency of Pinus growing near the upper timber line on Elbrus Mt in the Central Caucasus that suggests a westerlies of air masses and transfer of microparticles. A high abundance of non-pollen palynomorphs in pollen assemblages demonstrates a high potential for studying of human impact on mountain ecosystems. The first pollen data from the ice core evidences a promising resource of the high-altitude temperate glaciers as a flexible tool for atmospheric monitoring of microparticle transfer and fixing its seasonality and biotic relationships.</p><p>This work was supported by the Russian Science Foundation, project № 17-17-01270.</p>

scholarly journals A 40 Year Record in an Ice Core from the Dunde Ice Cap, China (Abstract)

1988 ◽  
Vol 10 ◽  
pp. 221 ◽  
Author(s):  
Wu Xiaoling ◽  
Lonnie G. Thompson
Keyword(s):  
Oxygen Isotope ◽  
Ice Core ◽  
Field Work ◽  
Tibet Plateau ◽  
Ice Thickness ◽  
Ice Cap ◽  
Pulse Radar ◽  
The North ◽  
Isotope Profile ◽  
Isotope Content

A cooperative glacio-climatological ice-core drilling and analysis program, administered by LIGC and BPRC, has been carried out since 1984. The major objective of this study is to extract from the Dunde ice cap records of the general environmental conditions, which include drought, volcanic activity, moisture sources, glacier net balance and possibly temperature over the last 3000 years. In 1984 a group of 18 Chinese scientists and an American scientist spent 6 weeks on the Dunde ice cap. The central objective of their research was to evaluate the potential of the ice cap to yield a lengthy ice-core climate record. Results of the 1984 field work and 1985 laboratory analysis are submitted here. The Dunde ice cap (38°96′N, 96°24.5′E) is located in the north-eastern section of the Tibet plateau, China. Its length is 10.9 km; the width varies from 2.5 to 7.5 km. The total area of the ice cap is 57 km2. A 16 m core was drilled at the first site, located on a flat part of the ice cap, 5150 m a.s.l. A 10.2 m ice core was drilled at the ice cap summit (5300 m). A series of shallow cores and 2 m pits were excavated at each of the two sites and in the lower section of the ice cap. A mono-pulse radar unit was used to determine ice thickness. The ice thickness ranged between 94 and 167 m, with an average thickness of 140 m. Using a thermistor cable, minimum temperatures of −9.1° and −9.5 °C were measured in the 16 m hole and 10.2 m hole respectively. Microparticle analysis of the ice core from the Dunde ice cap revealed a very high dust content, on average 16 × 105 particles (≥0.63 to ≤16 μ in diameter) per ml of sample, i.e. 3−4 times higher than the microparticle content in the Quelccaya ice cap, Peru, and 100 times higher than in the core from Byrd Station, Antarctica. Oxygen-isotope content ranged between −12 and −14 per mil. Initially it was anticipated that the oxygen-isotope content would produce a more negative value in the Dunde ice cap. More work is required to explain the mechanism controlling δ18o variation in the ice core from the Dunde ice cap. The microparticles, oxygen-isotope content, conductivity, and tritium measurements, together with stratigraphy, temperature and density, are presented in the figures. The 40 year net-balance record reconstructed from the ice-core and oxygen-isotope profile is in good agreement with data from precipitation and major temperature trends obtained for the last 30 years from Delingha meteorological station, which is located 160 km south-east of the ice cap.

scholarly journals Results From The Amery Ice Shelf Project

1982 ◽  
Vol 3 ◽  
pp. 36-41 ◽  
Author(s):  
W. F. Budd ◽  
M. J. Corry ◽  
T. H. Jacka
Keyword(s):  
High Strain ◽  
Ice Core ◽  
Snow Accumulation ◽  
Ice Thickness ◽  
Surface Slope ◽  
Ice Shelf ◽  
Substantial Growth ◽  
Basal Ice ◽  
Amery Ice Shelf ◽  
Comprehensive Study

The major results from a comprehensive study of the Amery Ice Shelf are presented, following the work of a wintering expedition in 1968 and supplemented by further measurements during the summer seasons of 1969 to 1971. The Programme included ice-core drilling, oversnow surveys for ice movement and optical levelling, ice-thickness sounding, and measurements of snow accumulation. The new data obtained provide the basis for a more accurate assessment of the mass balance and dynamics of the ice shelf than was possible from the earlier surveys. The results indicate a substantial growth of basal ice under the ice shelf inland where the ice thickness is greater than 450 m. Further towards the ice front the high strain thinning is approximately balanced by the horizontal ice advection. The velocity distribution over the ice shelf is primarily governed by a substantial surface slope towards the ice front and high restraining shear stress along the sides.

scholarly journals Features of meteorological events preserved in a high-resolution Law Dome (East Antarctica) snow pit

2002 ◽  
Vol 35 ◽  
pp. 463-470 ◽  
Author(s):  
Alison J. McMorrow ◽  
Mark A. J. Curran ◽  
Tas D. Van Ommen ◽  
Vin I. Morgan ◽  
Ian Allison
Keyword(s):  
High Resolution ◽  
Austral Summer ◽  
Snow Accumulation ◽  
East Antarctica ◽  
Synoptic Scale ◽  
High Accumulation ◽  
Oxygen Isotope Ratios ◽  
Source Regions ◽  
Ion Species ◽  
Very High

AbstractSnow-pit and shallow firn-core records of oxygen isotope ratios (δ18O) and trace ion species were generated at a high-accumulation site on Law Dome, East Antarctica. Concordance between accumulation events identified in records up to 7.7 km a part confirms that the observed glaciochemical variations are the result of regional rather than local surface effects. This allows calibration of the snow-pit records with measured meteorological parameters. Net accumulation periods that comprise the snow-pit record are identified using hourly snow-accumulation measurements from a co-located automatic weather station (AWS). Particular focus is given to three net accumulation periods preserved during austral summer 1999/2000 that correspond to the top 0.5 m of the snow pit. Local meteorological conditions recorded during the summer accumulation periods by the AWS are combined with regional and synoptic-scale meteorology derived from Casey station (110 km away) and Advanced Very High Resolution Radiometer satellite imagery to identify potential source regions for chemical signals preserved in summer snow at Law Dome.

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