A sea floor investigation was performed in the fiord of Hornsund by means of the seismoacoustic profiling, echosounding and core sampling. The main seismoacoustic sea floor units were recognized (the methods used according to Kowalewski et al. 1987a) and characterized on the basis of their relations to geomorphology and geological evolution. The bathymetrical sketch and the resulting geomorphological description of the bottom were prepared. The surface of the sea bottom and the surface of the bedrock displayed an irregular high relief with large sills dividing the fiord sea floor into several basins. Four main types of the sills were distinguished: burried sills, accumulative sills, rock sills and rock-accumulative sills. Within the internal Basins I and II there were thick (up to 170 m) covers of the glaciomarine ice-front deposit with changing thin ( 1 -5 m) blanket of the glaciomarine muds at the bottom surface. The Basin III had a cover of the glacial and glaciomarine deposits of variable lithology, genesis and age. The most external Basin IV had a cover o f glaciomarine muds up to 4 0 - 5 0 m thick, deposited on the tills. Four main glacial episodes were recognized, most probably referring to the stadials of Lisbetdalen, Slaklidalen, Revdalen and to the Little Ice Age.

The purpose of this study was to present the current state of avifauna in the vicinity of Polish Polar Station, at Hornsund (SW Spitsbergen). During four seasons (2003-2006) ten bird species were recorded as breeding there. Among them colonial little auk and Arctic tern were most abundant. Six additional species were noted during the breeding season but none of them bred there and their visits in the study plots were a consequence of their nesting nearby study area. Remaining 11 species were recorded during migration. The most pronounced changes over the last 35 years has been a considerable increase in number of barnacle geese exploiting the tundra as their foraging and resting area.

The differentiation of the isotopic composition of glacial water in some Hornsund glaciers was found to depend on its position with respect to the firn line, situation in the circulation system and on seasonal variations of air temperature. Intensive ice thawing in the ablation zone is marked by decreased values of the tritium content in the discharge of the glacier, whereas water from thawing snow nad firn increases these values. The isotopic differentiation which occures in waters in the main flow systems indicates the magnitude of the shares of water from thawed ice firn and snow in the total drainage of the glacier.

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.

The thermal state of permafrost is a crucial indicator of environmental changes occurring in the Arctic. The monitoring of ground temperatures in Svalbard has been carried out in instrumented boreholes, although only few are deeper than 10 m and none are located in southern part of Spitsbergen. Only one of them, Janssonhaugen, located in central part of the island, provides the ground temperature data down to 100 m. Recent studies have proved that significant warming of the ground surface temperatures, observed especially in the last three decades, can be detected not only just few meters below the surface, but reaches much deeper layers. The aim of this paper is evaluation of the permafrost state in the vicinity of the Polish Polar Station in Hornsund using the numerical heat transfer model CryoGrid 2. The model is calibrated with ground temperature data collected from a 2 m deep borehole established in 2013 and then validated with data from the period 1990-2014 from five depths up to 1 m, measured routinely at the Hornsund meteorological station. The study estimates modelled ground thermal profile down to 100 m in depth and presents the evolution of the ground thermal regime in the last 25 years. The simulated subsurface temperature trumpet shows that multiannual variability in that period can reach 25 m in depth. The changes of the ground thermal regime correspond to an increasing trend of air temperatures observed in Hornsund and general warming across Svalbard.

Five species of Tardigrada were found in two moss samples collected from the Hornsund area (Ariekammen, Spitsbergen) including one new to science. The new species, Isohypsibius karenae sp. n., differs from the other similar congeners mainly by having a different type of cuticular sculpture, a different macroplacoid length sequence, by the presence of lunules and cuticular bars under claws as well as by some morphometric characters. The current study increases the number of Isohypsibius species known from Svalbard to thirteen.

This paper describes in detail the phe notypic traits of the newly discovered Leptolyngbya sieminskae sp. n. (Cyanobacteria). The species was found at two islands of the Svalbard archipelago (Spitsbergen and Nordaustlandet) in habitats which differed in humidity, water sources and altitude. The research was conducted at two fjords: on the southern side of Spitsbergen – Hornsund (77 ° N, 015 ° E) and the north−west side of Nordaustlandet – Murchisonfjord (80 ° N, 018 ° E). Although Leptolyngbya sieminskae was found in different latitudes no significant morphological differences were found between the specimens from both sites. The only visible difference is in the thickness of filaments and sheaths.

Hornsund, an Arctic fjord in the west coast of Spitsbergen (Svalbard), was selected as All Taxa Biodiversity Inventory (ATBI) site under EU 5th Framework Concerted Action BIOMARE (2000–2002), especially due to its pristine, undisturbed natural character. On the base of large material (89 stations located throughout the fjord and 129 Van Veen grab samples) collected during cruises of RV Oceania in July in 2002, 2003, 2005 and 2007 and literature search a comprehensive list of species recorded within Hornsund area, on the soft bottom with depth range of 30–250 m is provided. Over 220 species were identified including 93 species of Polychaeta, 62 species of Mollusca and 58 species of Crustacea. Species list is supported by information on the zoogeographical status, body length and biological traits of dominant species. Need for further research on Hornsund soft bottom fauna with more sampling effort is highlighted.

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.

Sphagnum riparium (Bryophyta) is recorded and described from the Wedel Jarlsberg Land on Spitsbergen, the Arctic Svalbard Archipelago. It is the northernmost known population of the species in the Northern Hemisphere. The distribution of the two known Sphagnum species in the Hornsund area, viz. S. riparium and S. squarrosum is mapped and described.

Certain chemical parameters such pH, specific electric conductivity (SpC) and concentrations of chloride ions (Cl-) have been analysed in samples of precipitation collected close to the Polish Polar Station at Hornsund (PPS), SW Spitsbergen. On the basis of seasonal data from years 1993-1994 and 1998-1999, some differences are apparent from the two sets. There is also a marked difference in the seasonal results, especially with respects to pH values; summer precipitation (pH of which can be as low as 3.78) is much more acidic than winter. This was particularly notable in respect of the summer of 1993, and was presumably the result of a relatively unusual atmospheric circulation and a high influx of airborne contaminants from Europe. The wide variation in specific electrical conductivity measurements is considered to be related to variations in wind direction and speed. That precipitation the highest total dissolved salts, of 11.7 mm w.e. (water equivalent), (November 1993), provided 10.7 g of salt per square metre of tundra near the Polish Polar Station. The proximity of the sea, consequently the development of marine aerosols, largely determines the chemical nature of the precipitation. Thus, variations in the chloride ion concentrations during the study periods more or less reflect the variations in the marine aerosol influences on the nature of the polluted precipitation. An analysis of the atmospheric circulation reveals that the most acid precipitation occurs most frequently in the C-8 type of circulation (cyclonic S + SW) and also, less so, for type C-3 (anticyclonic S + SW).

Research on the chemistry of atmospheric precipitation in the Hornsund region of Svalbard has been extended by analysis of the organic contents. In rainfall samples collected in September 2003, the organics were separated by solid phase extraction (SPE), eluted and analysed on gas chromatograph coupled to a mass selective detector (GC/MS). Rainfall pH was in the range 4.72–5.45, the low values suggesting possible pollution. Concentrations of inorganic ions, expressed as total dissolved salts (TDS), were 5.40–13.18 mg L–1. Non-sea-salt (nss) sulphates were in the range 5–11 μeq L–1. In all samples, long-chain alkanes with chain length up to C36, and their methyl derivatives were detected. Among aromatic compounds biphenyl, dibenzofuran and its methyl derivatives were found. Polycyclic aromatic hydrocarbons (PAHs) were represented by naphthalene, phenanthrene, fluorene, acenaphthene, fluoranthene and pyrene. There were no PAHs with higher numbers of rings. The synoptic meteorological conditions in September 2003 indicate that all organic and inorganic pollutants were of local origin.

Measurements of CO2 concentrations in soil air were taken in the summer seasons of 1998 and 2001 in SW Spitsbergen. The measurements were carried out in three small non-glaciated catchments in the Hornsund region close to the Polish Polar Station. The preliminary measurements were made using a Dräger's pump and ampules which contained an alkaline absorbent (1998). Later (2001), a new more accurate apparatus which uses a gravimetric method was tested. A variety of different geographical situations was chosen for the CO2 measurements. These included areas which differed in respect of the local hydrology, terrain relief, exposure to solar radiation, distance from the sea and quantity of seabird excrements in the soil. The measured concentrations of soil CO2 varied between 0.05 and 0.3% (with one exceptionally high value close to 0.5%). Owing to the local conditions, the differences between CO2 concentrations seem closely to relate to the specific properties of each catchment. Much of the biogenic CO2 present in water that circulates in tundra catchments which have a limestone foundation becomes involved in the dissolution of that limestone. In July 2001, about 40% of the CO2 was used in the dissolution of the carbonate rocks (30.3 kg/km2 month), the “free” CO2 being transported to the sea at Isbjřrnhamna Bay (40.4 kg/km2 month). In contrast, the water flowing through acidic rocks are rich in “free” CO2. The concentrations of dissolved and transported HCO3– ions from the polar catchments are closely correlated with variations in the daily production of biogenic CO2.

Studies of the Quaternary evolution of the Hornsund Region in Spitsbergen focused in nine key areas, in which detailed fieldworks with mapping and sampling to radiocarbon and thermoluminescence analyses have been done. Glacial history of the Hornsund Region is known from the Torellkjegla (Holsteinian) Interglacial up to the recent times. The Wedel Jarlsberg Land (Saalian) Glaciation was the most widespread in this part of Spitsbergen and consisted of two stades(?). It was followed by considerable glacier retreat during the Bogstranda (Eemian) Interglacial, the latter being represented by development of soils. Four glacier advances (the two younger ones are the Lisbetdalen and the Slaklidalen stages) occurred during the Sörkapp Land (Vistulian) Glaciation. Three glacier advances (Gronfjorden and Revdalen stages, followed by the Little Ice Age) were recognized for the Holocene. The oldest and highest (although somewhat questionable) raised marine beaches come presumably from the Wedel Jarlsberg Land Glaciation. The beaches 80-100 m a.s.l. were formed during the Bogstranda (Eemian) Interglacial. The beaches 20-60 m a.s.l. are correlated with the Sórkapp Land Glaciation. All the lower marine beaches were formed during the Holocene.

The Hornsund region is characterised by a topoclimatic variation, which results principally from the local orography, the vicinity of open sea and the two contrasting environments: non-glaciated and glaciated. The specific types of atmospheric circulation determine the local thermal differences. The west coast is characterised by the most favourable thermal conditions, where air temperature is largely determined by foehn processes. The temperature at the Baranowski Station is 0.8°C higher on average than that of the Polish Polar Station on the northern shore of Hornsund . The temperature in the northern shore of the fjord happens to be higher than that on the west coast, which is attributed to the NW cyclonic inflow of cool Arctic air masses. During intermediate weather, when ground frost-thaw takes place, the northern shore of Hornsund is warmer by 0.5°C ; whereas, during moderately frosty weather, it is warmer by 0.2°C than the west coast. The differences result from the effect of the warmer fjord waters on the surrounding air temperature. During moderately warm weather, more favourable conditions occur near the Baranowski Station, expressed by the mean temperature difference of 0.9°C. The greatest temperature difference of 1.5°C on average is normally recorded during warm weather.

Works connected with execution of geodesic and photogrammetric surveys and with setting up maps in the scale of 1:5000 of environs of the Polish Polar Station on the Isbjörnhamna Bay and in the scale of 1:500 of the area covered with buildings of the Station are discussed.

Glacierized fjords are dynamic regions, with variable oceanographic conditions and complex ice−ocean interactions, which are still poorly understood. Recent studies have shown that passive underwater acoustics offers new promising tools in this branch of polar research. Here, we present results from two field campaigns, conducted in summer 2013 and spring 2014. Several recordings with a bespoke two−hydrophone acoustic buoy were made in different parts of Hornsund Fjord, Spitsbergen in the vicinity of tidewater glaciers to study the directionality of underwater ambient noise. Representative segments of the data are used to illustrate the analyses, and determine the directions of sound sources by using the time differences of arrivals between two horizontally aligned, broadband hydrophones. The results reveal that low frequency noise (< 3 kHz) is radiated mostly from the ice cliffs, while high−frequency (> 3 kHz) noise directionality strongly depends on the distribution of floating glacial ice throughout the fjord. Changing rates of iceberg production as seen for example in field photographs and logs are, in turn, most likely linked to signal amplitudes for relevant directions. These findings demonstrate the potential offered by passive acoustics to study the dynamics of individual tidewater glaciers.

A section of a gravel−dominated coast in Isbjørnhamna (Hornsund, Svalbard) was analysed to calculate the rate of shoreline changes and explain processes controlling coastal zone development over last 50 years. Between 1960 and 2011, coastal landscape of Isbjørnhamna experienced a significant shift from dominated by influence of tide−water glacier and protected by prolonged sea−ice conditions towards storm−affected and rapidly changing coast. Information derived from analyses of aerial images and geomorphological mapping shows that the Isbjørnhamna coastal zone is dominated by coastal erosion resulting in a shore area reduction of more than 31,600 m 2 . With ~3,500 m 2 of local aggradation, the general balance of changes in the study area of the shore is negative, and amounts to a loss of more than 28,000 m 2 . Mean shoreline change is −13.1 m (−0.26 m a −1 ). Erosional processes threaten the Polish Polar Station infrastructure and may damage of one of the storage buildings in nearby future.

This study reports on the accumulation rates and ²¹⁰Pb fluxes in Spitsbergen, Svalbard archipelago, wetlands. Six peat cores were collected in the Hornsund region, SW Spitsbergen (77°N) in 2007. The ages of peat layers were obtained with the Constant Flux/Constant Sedimentation and Constant Rate of Supply models based on the ²¹⁰Pb-dating technique. The obtained ²¹⁰Pb flux values ranged from 28 to 50 Bq m ^–2 y ^–1, which was consistent with the level of 222Rn emanation estimated for northern latitudes. The values of vertical and mass accumulation rates were slightly lower than reference data for peatlands of 50°−70°N. Furthermore, the vertical variations of peat accumulation rates exhibited the highest values in the upper part of the examined cores. The increasing tendency may be due in part to low compaction and low decomposition in the youngest peat layers. The analysis of the peat accumulation rate as a function of organic matter content and bulk density revealed positive and negative correlations, respectively, rather strong in both cases. The air temperature and precipitation gradients in the last few decades may have affected peat growth rates, which should be thoroughly investigated in future projects. Undoubtedly, the reported findings have provided a valuable addition to the relatively sparse dataset on recent peat deposits in Spitsbergen.

Intertidal zone of four gravel beaches in Hornsund Fjord (West Spitsbergen) were investigated in order to study macrofaunal distribution and diversity in these poor habitats. A total of 12 macrofaunal taxa were found in the collected material. The most frequent and the most abundant taxon was Lumbricillus sp. (Oligochaeta). The next most numerous group were juvenile Gammarus spp. juv. The fauna included also polychaetes, molluscs and other crustaceans. The diversity measured with Shannon-Weaver index was low and varied from 0 to 1.4. The analysis revealed that there were no statistically important differences in macrofaunal distribution among stations in fjord. However there were significant differences among various tidal mark zones and high patchiness in animals abundance at each station. Also species composition, density and biomass were diversified along the tide level profile.

Using High Performance Liquid Chromatography, concentrations of uric acid in the surface waters of two non-glaciated catchments (Fugle and Dynamisk) on Spitsbergen were measured. Measurements of specific conductivity enabled us to perform tests on the dissolution of the carbonate rocks present in both catchments in both natural and aqueous solutions of uric acid. Samples of calcium urate were made and its water solubility determined. Given a knowledge of concentrations of uric acid, calcium ions and calcium urate solubility product, an estimate of the role of uric acid in the dissolution of carbonate rocks was possible. Uric acid increases the dissolution of carbonate rocks by c. 12.5% in case of the Fugle catchment and 7% in Dynamisk.

Significant retreat of glaciers terminating in Hornsund Fjord (Southern Spits− bergen, Svalbard) has been observed during the 20th century and in the first decade of the 21st century. The objective of this paper is to present, as complete as possible, a record of front positions changes of 14 tidewater glaciers during this period and to distinguish the main factors influencing their fluctuations. Results are based on a GIS analysis of archival maps, field measurements, and aerial and satellite images. Accuracy was based on an assessment of seasonal fluctuations of a glacier’s ice cliff position with respect to its mini− mum length in winter (November–December) and its maximum advance position in June or July. Morphometric features and the environmental setting of each glacier are also presented. The total area of the glacier cover in Hornsund Fjord in the period of 1899–2010 diminished approximately 172 km 2 , with an average areal retreat rate of 1.6 km 2 a −1 .The recession rate increased from ~1 km 2 a −1 in first decades of the 20th century up to ~3 km 2 a −1 in years 2001–2010. The latest period was more thoroughly studied using optical satellite images acquired almost every year. The importance of glacier morphology and hypsometry, as well as fjord bathymetry and topography is analyzed. Large glacier systems with low slopes terminating in deeper waters are retreating faster than small steep glaciers terminating in shallower water. A relation between mean annual air temperature and aerial retreat rate of tidewater glaciers was found for long time scales. A sudden temperature in − crease, known as the early 20th century warming in Svalbard, and an increase in temperatures during recent decades are well reflected in deglaciation rate. Influence of sea water temperatures on calving and retreat of glaciers was considered and is significant in short−time intervals of the last decade. Surge events are non−climatic factors which com − plicate the record. They are reflected in front advance or fast retreat due to a massive calving depending on the relation between ice thickness and water depth. Despite the influence of many factors, the response of tidewater glaciers to climate change is evident. The average linear retreat rate of all the tidewater glaciers in Hornsund amounted to ~70 ma −1 in 2001–2010 and was higher than the average retreat of other Svalbard tidewater glaciers (~45 ma −1 ). Thus, glaciers of this basin can be considered as more sensitive to climate than glaciers of other regions of the archipelago.

This paper presents the results of direct 3−D fault displacement monitoring along the northern shore of Hornsund Fjord, SW Spitsbergen, Svalbard. The fault displacements have been recorded using three permanently installed optical−mechanical crack gauges since 2009. The monitoring data from all three sites provided evidence for a remarkable slip event that lasted from September 2011 to May 2012. The cause is discussed in some detail with consideration given to both exogenic (temperature changes, surface processes) and endogenic processes (isostatic rebound and regional seismicity). It is proposed that transient fault slips recorded had a tectonic origin and were caused by approximately W−E oriented compression corresponding to regional compression in the Svalbard area.

The succesive fifth whole-year research expedition stayed at the polar station of the Institute of Geophysics, Polish Academy of Sciences, in the Hornsund fiord from July 1982 to August 1973. Continuous observations as well as sejsmologic, magnetic and meteorological records, constituting continuation of the investigations started in summer 1978. were carried out by the wintering group of 8 men. Also separate research programmes: physics of atmosphere and ionosphere, sedimcntologo-oceanological, geomorphological and medical investigations, including observations of white bears, were realized. Many technical works, repairs and adaptations were carried out as well.