Future surface mass balance of the Elbrus Glacial Complex under climate change

<p>The evolution of the Elbrus glacier complex, consisting of two dozen of glaciers, in the last two decades of the 20th century and at the beginning of the 21st century generally corresponded to the trend of a decrease in the glaciated area of ​​the whole Caucasus. Over the period 1960-2014, the area of ​​Elbrus glaciation decreased by approximately 15%, and over two decades 1997-2017 - by almost 11%. As of 2017, the area of ​​Elbrus glaciation was estimated to ca. 112 sq. km, its volume exceeded 5 cub. km. Elbrus glaciation contributes significantly to the formation of the hydrological regime in the region, and, therefore, may be considered as a major challenge ti the regional socio-economic development. The latter circumstance requires an accurate assessment of the glacial runoff, and, consequently, the calculation of the surface mass balance of the glacial complex. We use an energy balance model to calculate the current and future surface mass balance. The series of observations at the Terskol meteorological station, located fifteen kilometers from the southern spurs of Elbrus, and the Mestia meteorological station, located somewhat further, on the territory of Georgia on the southern slope of the Main Caucasian ridge, as well as data from automatic weather stations on Elbrus slopes and on Djankuat glacier a few tens of kilometers from Elbrus, were applied for model forcing to reproduce present surface mass balance. The modeling results were validated by comparison with the measured surfave mass balance components on Garabashi glacier, one of the glaciers on the southern slope of Elbrus. Climate projections until the end of the 21st century for the Elbrus region were composed on the basis of multi-model results of regional climate modeling within the CORDEX project for various scenarios.</p><p>We demonstrate that simultaneous surface air temperature and insolation growth accompanied by decrease in precipitation, predicted by multi-model regional climate modeling and downscaled to the Central Caucasus area, will cause essential lifting of the equilibrium line altitude and shrinking of accumulation area. As a result, we must expect an accelerated degradation of Elbrus glaciation in forthcoming decades.   </p><p>The reported study was funded by RFBR and RS, project number 21-55-100003</p>

Glaciers of Grandes Jorasses: an open-air laboratory for glacier monitoring systems development

<p> </p><p>Glaciological phenomena can have a strong impact on human activities in terms of hazards and freshwater supply. Therefore, a scientific observation is fundamental to investigate their current state and recent evolution. To this aim, experimenting innovative scientific survey methodologies and equipment is of primary importance. Strong efforts in this field have been spent in the glacial complex of the Grandes Jorasses massif (Mont Blanc area), where several ice break-offs glacial outburst triggered from the Planpincieux Glacier snout and the Whymper Serac and threatened the underling Planpincieux valley in the past. From 2009, the glacial complex has become an open filed laboratory where a wide set of close-range remote sensing survey systems have been developed and applied to investigate the glacial state and dynamics.</p><p>Two continuous monoscopic time-lapse cameras observe the Planpincieux Glacier since 2013. Digital image correlation is applied to the photographs to measure the surface kinematics at different level of detail. During the monitoring, image analysis techniques allowed at classifying the instability processes of the terminus and at estimating the volume of the break-off events. Such investigation revealed the presence of possible break-off precursors and a monotonic relationship between glacier velocity and break-off volume, which might help for risk evaluation.</p><p>A robotised total station (RTS) is active since 2009 to monitor the Whymper Serac velocity (Grandes Jorasses Glacier). The operative distance between the total station and targets is approximately 5000 m. A network of several prisms is installed onto the serac, but the extreme conditions related to the high-mountain environment force to replace periodically the stakes that are lost. Besides the RTS, a monoscopic camera acquires hourly images of the serac for surface velocity measurements.</p><p>In addition to the permanent monitoring systems, surveys with four different terrestrial interferometric radars have been conducted in the Planpincieux Glacier between 2013 and 2019. Helicopter-borne LiDAR and terrestrial laser scanner provided the DEM of the Planpincieux Glacier in 2014 and 2015 respectively. A sequence of six DEMs has been also produced by aerial and UAV structure from motion in the time span 2017-2019. Finally, a helicopter ground penetrating radar campaign was conducted in 2013 to evaluate the thickness of the Planpincieux Glacier and Whymper Serac.</p><p>For what concerns the mountain glaciers, the survey activity conducted in the Grandes Jorasses massif since 2009 is probably one the most intensive and variegated in European Alps. This makes such an environment an open-air laboratory for experimenting close-range remote sensing monitoring systems that it is ready for new research activities and monitoring solutions development.</p><p> </p><p> </p>

Quaternary sediments of glacial series of Volhyn Polissia as a source of mineral resources

Material composition of Quaternary sediments in the Volhyn Polissia studied enough. The same applies to the accumulation of deposits of glacial complex. Data of mineralogy of glacial and fluvioglacial sediments and their petrographic composition of coarse fragment component was considered. The possibility of using of the material for search of non-traditional mineral deposits in Volhyn Polissya was noted. Key words: Volhyn Polissia, Dnieper glaciation, building materials, diamond, pyrope, amber, phosphate sandstone, native gold.

Séquence de la transition Illinoien–Sangamonien : forage IAC-91 de l'île aux Coudres, estuaire moyen du Saint-Laurent, Québec

A series of Pleistocene deposits extending over 155 m below sea level was drilled at Aux Coudres Island, in the middle St. Lawrence Estuary, Quebec. The series, which basis is unknown, is divided into two sedimentary units: the lower Baie-Saint-Paul Glacial Complex facies (−155 to −125 m), which is correlated with the Illinoian (isotopic stage 6), and a stratified sequence referred to as the île aux Coudres Formation. The latter is subdivided into four zones: a very compact lower clay (−125 to −102 m), rhythmites with Paleozoic schist debris (−102 to −71 m), and prodeltaic silts and deltaic sandy silts with brackish water benthic foraminifera (−71 to −2 m). The spore and pollen content indicates a schrub tundra followed by an afforestation sequence of a boreal forest that changes to an Abies forest and then to an interglacial mixed forest with Betula, Jugions, Carpinus or Ostrya, Carya, and, at the top, Betula, Tsuga, Quercus, and Ulmus. The accumulation of the sediments of the Île aux Coudres Formation required approximately 3500 years, beginning with a deep marine environment (about 300 m) followed by shallowing waters during the subsequent glacioisostatic rebound phase of the regression. The sedimentation is assigned to a main postglacial marine invasion, referred to as the Guettard Sea, which occurred prior to two regional glacial episodes and was partly contemporaneous with Bell Sea invasion in the Hudson Bay lowlands. A major postglacial sedimentary influx in the Atlantic Ocean, during the Illinoian-Sangamonian transition and at the beginning of the Sangamonian (transition 6–5 and early substage 5e) is inferred from this marine event.