Instytut Geofizyki

Warsaw, Poland

Instytut Geofizyki

Warsaw, Poland

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Dolnicki P.,University Pedagogiczny | Grabiec M.,University of Silesia | Puczko D.,Instytut Geofizyki | Gawor L.,Silesian University of Technology | And 2 more authors.
Polish Polar Research | Year: 2013

We present the variability of the thermal state and thickness of permafrost active layer at the raised marine beaches in Svalbard. The investigations were carried out using direct probing, thaw tube, ground temperature and radar soundings at Holocene strand plains 10-20 m a.s.l. in Fuglebergsletta (SW Spitsbergen) and at the shore of Kinnvika Bay (Nordaustlandet). Their results were compared to those obtained at other coastal sites in Svalbard. The ground temperature measurements were conducted in 2009 on August, recognized as the standard month for the maximum thawing during the last decade. The studied sites are typical for close to extreme active layer conditions on Svalbard. In Hornsund, the thawing depth exceeded 2 m, while in Kinnvika the active layer was thinner than 1 m. In Svalbard, the depth of thawing decreases generally from south to north and from the open sea coast to the central parts of islands. These differences are the consequence of diverse climatic conditions strongly determined by the radiation balance modified by a number of regional (e.g. ocean circulation) and local (e.g. duration of snow deposition) conditions.


Grabiec M.,University of Silesia | Puczko D.,Instytut Geofizyki | Budzik T.,University of Silesia | Gajek G.,University Marii Curie Sklodowskiej
Polish Polar Research | Year: 2011

The spatial distribution of snow thickness on glaciers is driven by a set of climatological, meteorological, topographical and orographic conditions. This work presents results of snow accumulation studies carried out from 2006 to 2009 on glaciers of different types: valley glacier, ice plateau and ice cap. In order to determine snow depth, a shallow radio echo-sounding method was used. Based on the results, the following snow distribution patterns on Svalbard glaciers have been distinguished: precipitation pattern, precipitation-redistribution pattern, redistribution pattern and complex pattern. The precipitation pattern assumes that the snow distribution on glaciers follows the altitudinal gradient. If the accumulation gradient is significantly modified by local factors like wind erosion and redeposition, or local variability of precipitation, the accumulation pattern turns into the precipitation-redistribution pattern. In the redistribution pattern, local factors play a crucial role in the spatial variability of snow depth. The complex pattern, however, demonstrates the co-existence of different snow distribution patterns on a single glacial object (glacier/ice cap/ice field).


Grabiec M.,University of Silesia | Jania J.A.,University of Silesia | Puczko D.,Instytut Geofizyki | Kolondra L.,University of Silesia | Budzik T.,University of Silesia
Polish Polar Research | Year: 2012

Hansbreen, a medium size tidewater glacier in Southern Spitsbergen (Svalbard) is one of the most intensively studied glaciers in the Arctic. This work presents new digital elevation models of its surface and basal topography based on data collected during GPS/GPR campaigns conducted in the spring seasons of 2005 and 2008, as well as on other recent topographic/bathymetric sources. The mean thickness of the glacier is calculated as 171 m and its volume is estimated to be 9.6 (±0.1) km3. The main feature of the bedrock morphology is a vast depression that is overdeepened below sea level and extends as far as 11 km upstream from the glacier front. This depression is divided into four individual basins by distinct sills that are related to the main geological/tectonic features of the area. The bedrock morphology affects considerably the glacier's surface topography. The influence of bedrock and surface relief on the subglacial drainage system geometry is discussed. Vast depressions on the glacier surface favor concentration of meltwater and development of moulin systems.


Laska M.,University of Silesia | Luks B.,Instytut Geofizyki | Budzik T.,University of Silesia
Polish Polar Research | Year: 2016

This paper presents a detailed study of melting processes conducted on Hansbreen - a tidewater glacier terminating in the Hornsund fjord, Spitsbergen. The fieldwork was carried out from April to July 2010. The study included observations of meltwater distribution within snow profiles in different locations and determination of its penetration time to the glacier ice surface. In addition, the variability of the snow temperature and heat transfer within the snow cover were measured. The main objective concerns the impact of meltwater on the diversity of physical characteristics of the snow cover and its melting dynamics. The obtained results indicate a time delay between the beginning of the melting processes and meltwater reaching the ice surface. The time necessary for meltwater to percolate through the entire snowpack in both, the ablation zone and the equilibrium line zone amounted to c. 12 days, despite a much greater snow depth at the upper site. An elongated retention of meltwater in the lower part of the glacier was caused by a higher amount of icy layers (ice formations and melt-freeze crusts), resulting from winter thaws, which delayed water penetration. For this reason, a reconstruction of rain-on-snow events was carried out. Such results give new insight into the processes of the reactivation of the glacier drainage system and the release of freshwater into the sea after the winter period. © 2016 Polish Academy of Sciences.


Ojala A.E.K.,Geological Survey of Finland | Salonen V.-P.,University of Helsinki | Moskalik M.,Instytut Geofizyki | Kubischta F.,University of Helsinki | Oinonen M.,University of Helsinki
Polish Polar Research | Year: 2014

A 2.5-metre-long marine core from Isvika bay in Nordaustlandet (80° N, 18° E) was AMS 14C dated and analysed for its sedimentological and magnetic parameters. The studied record was found to cover the entire Holocene and indicates major turnovers in the palaeo- hydrography and sedimentary depositional history. The area was deglaciated at around 11,300 BP. The early Holocene has indications of rapid melting of glaciers and frequent depo- sition of ice-rafted debris (IRD). The climatic optimum terminated with a probable glacier re-advance event occurring ca. 5800 cal BP. This event caused the deposition of a diamicton unit in Isvika bay, followed by a shift towards a colder and a more stratified hydrographic set- ting. The reduction in IRD indicates gradual cooling, which led to the stratification of the bay and eventually to more persistent fast sea-ice conditions by 2500 cal BP. For the last 500 years, Isvika has again been seasonally open.


Moskalik M.,Instytut Geofizyki | Grabowiecki P.,Instytut Geofizyki | Tegowski J.,University of Gdansk | Zulichowska M.,Jagiellonian University
Polish Polar Research | Year: 2013

Determination of High Arctic regions bathymetry is strictly dependent from weather and ice mass quantity. Due to safety, it is often necessary to use a small boat to study fjords area, especially close to glaciers with unknown bathymetry. This precludes the use of modern multi-beam echosounders, and so traditional single-beam echosounders have been used for bathymetry profiling. Adequate interpolation techniques were determined for the most probable morphological formations in between bathymetric profiles. Choosing the most accurate interpolation method allows for the determination of geographical regionalisation of submarine elevations of the Brepollen area (inner part of Hornsund, Spitsbergen). It has also been found that bathymetric interpolations should be performed on averaged grid values, rather than individual records. The Ordinary Kriging Method was identified as the most adequate for interpolations and was compared with multi beam scanning, which was possible to make due to a previously modelled single beam interpolation map. In total, eight geographical units were separated in Brepollen, based on the bathymetry, slope and aspect maps. Presented results provide a truly new image of the area, which allow for further understanding of past and present processes in the High Arctic.


Krysinski L.,Instytut Badawczy Drog i Mostow | Grad M.,University of Warsaw | Mjelde R.,University of Bergen | Czuba W.,Instytut Geofizyki | Guterch A.,Instytut Geofizyki
Polish Polar Research | Year: 2013

This paper presents a study of the seismic Pwave velocity and density structure of the lithosphereasthenosphere system along a 800 km long transect extending from the actively spreading Knipovich Ridge, across southern Spitsbergen to the Kong Karls Land Volcanic Province. The 2D seismic and density model documents 6-8 km thick oceanic crust formed at the Knipovich Ridge, a distinct continentocean-boundary (COB), the east ern boundary of the dominantly sheared Hornsund Fault Zone, and the eastern boundary of the Early Cenozoic West Spitsbergen Fold and Thrust Belt. The crustal continentocean transitional zone has significant excess of density (more than 0.1 g/cm3 in average), characteristic for mafic/ultramafic and highgrade metamorphic rocks. The main Caledonian suture zone between Laurentia and Barentsia is interpreted based on variations in crustal thickness, velocities and densities. A high velocity body in the lower crust is preferably interpreted in terms of Early Cretaceous magmatism channelled from an Arctic source southwards along the proto-Hornsund zone of weakness. The continental upper mantle expresses high velocities (8.24 km/s) and densities (3.2 g/cm3), which may be interpreted in terms of low heatflow and composition dominated by dunites. The lower velocities (7.85 km/s) and densities (3.1 g/cm3) observed in the oceanic lithosphere suggest composition dominated by primitive peridotites. The model of mantle allows for successful direct description of subcrustal masses distribution compensating isostatically uneven crustal load. The estimated low value of correlation between density and velocity in the mantle 0.12 kg.s.m-4 suggests that horizontal density differences between oceanic and continental mantle would be dominated by compositional changes.


Grad M.,University of Warsaw | Mjelde R.,University of Bergen | Czuba W.,Instytut Geofizyki | Guterch A.,Instytut Geofizyki | Schweitzer J.,NORSAR
Polish Polar Research | Year: 2011

In marine seismic wide-angle profiling the recorded wave field is dominated by waves propagating in the water. These strong direct and multiple water waves are generally treated as noise, and considerable processing efforts are employed in order minimize their influences. In this paper we demonstrate how the water arrivals can be used to determine the water velocity beneath the seismic wide-angle profile acquired in the Northern Atlantic. The pattern of water multiples generated by air-guns and recorded by Ocean Bottom Seismometers (OBS) changes with ocean depth and allows determination of 2D model of velocity. Along the profile, the water velocity is found to change from about 1450 to approximately 1490 m/s. In the uppermost 400 m the velocities are in the range of 1455-1475 m/s, corresponding to the oceanic thermocline. In the deep ocean there is a velocity decrease with depth, and a minimum velocity of about 1450 m/s is reached at about 1.5 km depth. Below that, the velocity increases to about 1495 m/s at approximately 2.5 km depth. Our model compares well with estimates from CTD (Conductivity, Temperature, Depth) data collected nearby, suggesting that the modelling of water multiples from OBS data might become an important oceanographic tool.


Markowicz K.M.,Instytut Geofizyki | Zawadzka O.,Instytut Geofizyki | Stachlewska I.S.,Instytut Geofizyki
Przeglad Geofizyczny | Year: 2010

Optical properties of a volcanic aerosol obtained by direct observations from Radiation Transfer Observatory at the Institute of Geophysics University of Warsaw and Aerosol and Radiation Observatory SolarAOT in Strzyzów (south eastern part of Poland) together with Meteosat Second Generation observations are discussed. Aerosol optical properties measured by the Multi-Filter Rotating Shadowband Radiometer (Model MFR-7), Microtops sun photometer, and CHM-15K ceilometer between 14 and 23 April 2010 are investigated. Back-trajectories calculated for 16 and 17 April show advection of air masses from Iceland in the lower and the middle troposphere. Satellite observations performed by the Spinning Enhanced Visible and Infrared Imager (SEVIRI) instrument onboard of the MSG2 confirmed ash over Poland. Unfortunately, cloudy conditions during this day prevented remote observations of the atmosphere's optical properties from the ground. However, surface observations performed on 17 April by the ceilometer indicate volcanic ash layers. At around midnight first ash layer appeared at 5 km. One hour later the second layer between 3 and 4 km was observed. An aerosol layer between 0.5 and 2 km was also measured, however it is difficult to determine the type of remotely sensed particles. After sunset very weak ash clouds were recorded between top of the boundary layer and 4 km. During the day those ash layers were not measured, probably due to a poor signal to noise ratio of the ceilometer's signal. Extinction coefficient for volcanic ash was estimated as 0.02-0.03 km″1 and aerosol optical thickness was calculated about 0.03 at 1064 nm. Sun photometers' observations at both stations show small total aerosol optical thickness which varies between 0.11 and 0.16 (at 500 nm) during 17 and 18 April 2010. However, the mean aerosol optical thickness for April is about 0.25.


Okon J.,Instytut Geofizyki | Gizejewski J.,Instytut Geofizyki | Janik T.,Instytut Geofizyki
Polish Polar Research | Year: 2016

The Polish Geophysical Expedition to West Antarctica in 1979-1980 was carried out by the Institute of Geophysics, Polish Academy of Sciences. Beside deep seismic soundings, 12 multi-channel seismic profiles, with a total length of ca 1000 km have been recorded north and east of the South Shetland Islands and in the Bransfield Strait, but they have never before been completely interpreted and published. All profiles have been processed with modern processing flow including time migration. Profiles crossing the South Shetland Trench revealed distinct reflector inside continental slope, which has been interpreted as border between buried accretionary prism and overlying slope sediments of glacial-marine origin. Profiles in the Bransfield Strait show traces of the Last Glacial Maximum (LGM) in the form of glacial foreground valleys, with some of them used as weak spots for young age volcanic intrusions. This paper is the first comprehensive geological interpretation of collected dataset and differences between results from other expeditions are discussed. © 2016 Polish Academy of Sciences.

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