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1

Realizacja projektu naukowego w zakresie podmorskiej sekwestracji CO₂ w południowej części Morza Bałtyckiego

Zajfert G., Tęgowski J., Sokołowski A., Latała A., Gorska N.

Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie

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2015

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nr 11

3--8

PL

Wzrost emisji gazów cieplarnianych do atmosfery staje się ważnym problemem wielu krajów na świecie. Jednym ze sposobów ograniczenia ich emisji jest geologiczna sekwestracja CO₂ pochodzenia antropogenicznego. W celu poznania możliwości stosowania tego rozwiązania na skalę przemysłową prowadzi się projekty naukowe i działania demonstracyjne. W artykule opisano realizację projektu badawczego, dotyczącego sekwestracji CO₂ w strukturach podmorskich w Polskiej Wyłącznej Strefie Ekonomicznej Morza Bałtyckiego. W efekcie realizacji projektu powstała szeroka baza danych i informacji o charakterze interdyscyplinarnym. Na podstawie ich analizy przedstawiono wstępne wnioski dla potencjalnej lokalizacji podmorskiego zatłaczania dwutlenku węgla. Ponadto projekt dostarczył cennych doświadczeń, które mogą posłużyć jako wytyczne do postępowania przy realizacji sekwestracji na skalę przemysłową.

EN

Global climate changes, which are mainly related to human activity, including emission of anthropogenic CO₂, resulted in significant intensification of research activities which focus on development of the technologies enable to reduce anthropogenic emissions. Carbon Capture and Storage (CCS) is regarded as a key technology for the reduction of CO₂ emissions from industrial sources an international level. This paper presents the first research study on potential CCS implementation in the Polish Exclusive Economic Zone of the Baltic Sea. The main place of interest is the undersea geological structure of B3 oil field. Currently, oil field is operated by LOTOS Petrobaltic company. For the purposes of the project the structure has been identified and characterized, basing on archival data and research in 2012.It has been shown, that the anticlinal form of reservoir is closed form and has the potential trapping properties, further more confirmed the tightness of overburden. It has been identified close situated fault, which could be a potential place for leakage and migration of CO2.The fault is inactive, without signs of hydrocarbon migration. Geochemical research of bottom sediments and waters near bottom indicate the conditions typical for the southern part of the Baltic Sea, low salinity and oxygen content, low concentration of hydrogen sulphide and methane. The seabed there is inhabited by very few organisms resistant to adverse factors of the habitat in the study area. The potential biological consequences of a gas leakage can be assessed as limited.

2

Principal Component and Cluster Analysis for determining diversification of bottom morphology based on bathymetric profiles from Brepollen (Hornsund, Spitsbergen)

Moskalik M., Tęgowski J., Grabowiecki P., Żulichowska M.

Oceanologia

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2014

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No. 56 (1)

59--84

EN

Navigation charts of the post-glacial regions of Arctic fjords tend not to cover regions from which glaciers have retreated. Whilst research vessels can make detailed bathymetric models using multibeam echosounders, they are often too large to enter such areas. To map these regions therefore requires smaller boats carrying single beam echosounders. To obtain morphology models of equivalent quality to those generated using multibeam echosounders, new ways of processing data from single beam echosounders have to be found. The results and comprehensive analysis of such measurements conducted in Brepollen (Hornsund, Spitsbergen) are presented in this article. The morphological differentiation of the seafloor was determined by calculating statistical, spectral and wavelet transformation, fractal and median filtration parameters of segments of bathymetric profiles. This set of parameters constituted the input for Principal Component Analysis and then in the form of Principal Components for the Cluster Analysis. As a result of this procedure, three morphological classes are proposed for Brepollen: (i) steep slopes (southern Brepollen), (ii) flat bottoms (central Brepollen) and gentle slopes (the Storebreen glacier valley and the southern part of the Hornbreen glacier valley), (iii) the morphologically most diverse region (the central Storebreen valley, the northern part of the Hornbreen glacier valley and the north-eastern part of central Brepollen).

3

Applications of the Huang – Hilbert transformation in non-invasive research of the seabed in the Southern Baltic Sea

Grabowski M., Tęgowski J., Nowak J.

Hydroacoustics

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2014

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Vol. 17

69--78

EN

This article aims at describing methods for extracting the Quaternary facies and detection of a buried pipeline at the bottom with the Huang – Hilbert transformation (HHT) based on acoustic data recorded by the sub-bottom profiler (SBP). The aforementioned transformation allows a study of nonlinear and/or non-stationary phenomena. A good example of this type of problem is the propagation and reflection of acoustic waves in water and the geological formations occurring beneath the surface of the seabed, as well as their scattering on objects at the bottom. The area in which research has been executed was the southern Baltic Sea, specifically the Outer Puck Bay for Quaternary facies and the stretch north from Władysławowo, for the pipeline. On the basis of the processed data with the HHT, Quaternary facies and the pipeline were determined and identified.

4

Use of the Hilbert-Huang Transform for characterization of gassy sediments in Eckernförde Bay

Tęgowski J., Ostrovsky I., Zamaryka M.

Hydroacoustics

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2011

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Vol. 14

237-244

EN

The bottom top layer of the central part of the Eckernförde Bay (Germany) consists of soft muddy sediments containing free methane gas. Locations of gas bubbles trapped in the sediment and gas seeps visualised with hydroacoustic data have been reported. The main goal of our study was to examine whether it was possible, using a singlebeam echosounder with relatively high frequency of the transmitted signal (120 kHz), to detect echo properties that could be indicative of the occurrence of free gas in the bottom sediments. During three days of measurements organised by Leibniz Institute of Marine Sciences (IFM-GEOMAR) in Kiel (Germany), the acoustic data were collected from boards of r/v Polarfuchs and r/v Littorina. The Hilbert-Huang Transform was applied to detect ‘gassy’ anomalies in backscattered signals from the bottom. The transformer decomposes signal into finite and small number of Intrinsic Mode Function (IMF) components with time-dependent amplitudes and frequencies. Certain IMF components carry information on variability of geoacoustic parameters, which can be indicative of presence of gas bubbles in the acoustically penetrated sediment as well as in the water column. Based on the shape of the echo signal envelope and its fading with range we characterized the signal attenuation in areas where gas was present. The rapid increase in acoustical wave attenuation in areas of intensive gas ebullition demonstrates good applicability of the method proposed.

5

The acoustic evidence for gas bubbles in the lake Kinneret sediments

Tęgowski J., Ostrovsky I., Zamaryka M.

Hydroacoustics

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2010

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Vol. 13

261-268

EN

The changes in gas content of bottom sediments are associated with rapid alterations of the ambient conditions (climate change, eutrophication, water level fluctuation, etc). In this paper we present results of acoustical measurements of sound scattering at gassy sediments in the subtropical Lake Kinneret (Sea of Galilee), where the 120 kHz single beam echosounder for bottom recognition was used. Measurements were carried out over a 10-year period along 14 standard transects. The echo parameterization method was applied to study acoustical features of bottom deposits and their variability in relation to sedimentary content of gas bubbles. Particularly, we examined the influence of water level fluctuations, affecting the presence of gas bubbles in the surface sediments on sound scattering and echo envelope parameters (spectral, wavelet, fractal, statistical and energetic). Presented results indicate the usefulness of the proposed method of backscattered signals processing for monitoring of the seafloor features.

6

Mapping seabed features from multibeam echosounder data using autocorrelation and multi-scale wavelet analyses

Tęgowski J., Nowak J., Hac B., Zamaryka M., Szefler K.

Hydroacoustics

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2010

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Vol. 13

253-260

EN

In the paper we propose the method of seabed morphological features extraction, which we have obtained from bathymetric and backscatter data, recorded by multibeam echosounder. Presented results of acoustical recognition of the southern Baltic Sea bottom are the part of measurements conducted in the band of 220 km length in the central part of Polish coastal water. The detailed analysis of seabed features were performed for area located in the vicinity of Kołobrzeg harbour. The degree of seafloor corrugation was determined by autocorrelation analysis of seafloor bathymetry. To which, we used estimation of autocorrelation length and fractal dimension, based on the shape of autocorrelation function. Moreover, the parameters of wavelet decomposition of bottom backscattering strength were the input to fuzzy logic clustering system allowing for outline of seafloor areas of similar morphological features. Both presented methods have confirmed its effectiveness in identifying morphological characteristics and types of the bottom surface.

7

Modelling multistatic of target detection

Klusek Z., Elminowicz A., Tęgowski J., Szczucka J., Dragan A.

Hydroacoustics

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2008

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Vol. 11

131-138

EN

The paper presents a numerical approach to modelling the detection of underwater targets with a bi- or multistatic active sonar systems in the shallow water areas using different waveform signals. The results of the numerical modelling of surface, bubble clouds and bottom reverberation for CW and using up and down time-varying instantaneous frequency of chirp signals are presented. Some suggestions are made on the basis of the development and practicality for the shallow sea modeling techniques and approaches to existing sonar models. The paper reports the literature of the model components required for active sonar modelling for different propagation conditions. Some examples of scattering of CW and chirp source signals at bubble clouds and corrugated surfaces, and coherence are given. Active propagation and the system performance are surveyed and modelled adaptable to the specific environmental condition of the shallow sea area of the Gdansk Gulf.

8

Extraction of seabed geomorphologic features of Svalbard fjords using high-resolution side scan sonar

Tęgowski J., Giżejewski J., Zieliński A.

Hydroacoustics

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2008

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Vol. 11

401-411

EN

This paper presents results of a study on the relationship between features of side scan sonar acoustic imagery of zones with active bedforms and geomorphologic seafloor characteristics. Acoustic measurements were conducted in Hornsund, a Svalbard fjord representing a periglacial environment with great intensity of morphodynamic processes and rapidly progressing changes of tidewater glaciers. Due to the intensity of these processes, Arctic fjords are the most promising areas to study the effects of climate change on the ecosystem. Acoustic identification of sedimentary structures and morphological forms created by currents and iceberg transport of glacier sediment away from the ice margin was performed. The spectral and fractal features of the recorded signals were analysed. The proposed analysis scheme allows identification of the morphodynamic active zones in the changing Arctic fjord environments. Measurements of acoustical features of seafloor surface were made during the 2006 Arctic cruise of r/v Oceania.

9

Synthesis and wavelet analysis of side-scan sonar sea bottom imagery

Tęgowski J., Zieliński A.

Hydroacoustics

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2006

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Vol. 9

199-208

EN

A backscattered side-scan sonar signal contains indirect information about the scattering surface, namely, the bottom sediment, character of bottom surface, and seafloor relief. This paper presents a method of automatic estimation of height of seafloor characteristic objects and micro relief reconstruction applying the measured shadow length. The proposed method utilises coefficients of two-dimensional discrete wavelet decomposition of a side-scan sonar image as the input to the self-organised neural network classification algorithm. The heights of seafloor characteristic objects were the basis for synthesis of a three-dimensional map of the bottom surface. The computations were conducted for data recorded in Hornsund Fjord (Spitsbergen Island, Svalbard Archipelago) during a habitat mapping experiment and for synthetic data. The verification of the proposed algorithm was made by comparison of computed results with calibrated video recordings.

10

Acoustic estimation of macrophytes in the Hornsund Fjord (The Svalbard Archipelago)

Kruss A., Tęgowski J., Wiktor J., Tatarek A.

Hydroacoustics

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2006

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Vol. 9

89-96

EN

In this paper we examine the use of side scan sonar for estimation and spatial distribution of macrophytes in Arctic conditions. Acoustic observation were verified by video recordings and biological samplings. Single beam echosounder was also used. The Hornsund Fjord represents a periglacial environment with great diversity of morphodynamic processes and sensitivity for global warming changes so it is one of the most promising areas to research the influence of the climate’s impact on ecosystem. Side scan sonar is a very effective and economic tool for mapping marine vegetation on the seafloor but interpretation of data still causes many problems especially in the specific conditions of the Arctic fjords (underwater rocks, postglacial sediments, steep slopes). We have created segmentation and classification algorithm based on the two-dimensional discrete wavelet decomposition of echo signals and fuzzy c-means data clustering. The algorithm was verified using biological data.

11

A laboratory study of breaking waves

Tęgowski J.

Oceanologia

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2004

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No. 46 (3)

365--382

EN

This paper deals with some aspects of the wave-breaking phenomenon. The objectives were to study wave-breaking criteria, and the probability of whitecap coverage under fully controlled wave conditions. An additional task was to in vestigate the characteristic spectral features of the noise produced by breaking waves and the acoustic energy generated during wave breaking events. A controlled experiment was carried out in the Ocean Basin Laboratory at MARINTEK, Trondheim (Norway). Waves were generated by a computer-controlled multi-flap wave maker, which reproduced a realistic pattern of the sea surface for the prescribed spectra. Using wave staff recordings and photographic techniques, correlations between the breaking parameters and the radiated acoustic emissions were established.

12

Nonlinear acoustical methods in the detection of gassy sediments in the gulf of Gdańsk

Tęgowski J., Jakacki J., Klusek Z., Rudowski S.

Hydroacoustics

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2003

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Vol. 6

151--158

EN

The application of nonlinear backscattering of acoustical signals in detection of gas bubbles in subsurface layer of sediment of the Gulf of Gdansk is presented. Gas bubbles concentration was estimated assuming that nonlinear scattering in soft sediments is similar as in water. Summary, difference and double harmonics generated only by gas bubbles were recorded and used for bubble density estimation. Comparisons of the concentrations received from different nonlinear components show generally agreement in calculated bubble density distributions, although values of densities acquired from almost identical volumes in a single transmission differ.

13

Acoustical techniques of underwater meadow monitoring in the Puck Buy (Southern Baltic Sea)

Klusek Z., Gorska N., Tęgowski J., Groza K., Faghani D., Gajewski L., Nowak J., Kruk-Dowgiałło L., Opioła R.

Hydroacoustics

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2003

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Vol. 6

79--90

EN

The main motivation of this paper was to develop acoustical techniques to monitor underwater meadows. The data, collected with down-looking echo sounder, were used to develop method of bottom detection and tracking and measurement of vegetation canopy height in the Puck Bay. This method and its accuracy are discussed in details. The other possibilities of recognition between covered and uncovered bottom were also reviewed. The effectiveness of using side scan sonar in study vegetation spatial distribution is demonstrated.

14

Experimental study of the formation of steep waves and breakers [commun.]

Massel S.R., Tęgowski J., Chomka M., Wichorowski M., Dąbrowski J., Stansberg C. T., Moe V.

Oceanologia

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2001

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No. 43 (3)

353-363

EN

Breaking waves (whitecaps) are one of the most important and least understood processes associated with the evolution of the surface gravity wave field in the open sea. This process is the principal means by which energy and momentum are transferred away from a developing sea. However, an estimation of the frequency of breaking waves or the fraction of sea surface covered by whitecaps and the amount of dissipated energy induced by breaking is very difficult to carry out under real sea conditions. A controlled experiment, funded by the European Commission under the Improving Human Potential Access Infrastructures programme, was carried out in the Ocean Basin Laboratory at MARINTEK, Trondheim (Norway). Simulation of random waves of the prescribed spectra by wave makers provided a very realistic pattern of the sea surface. The number of breaking waves was estimated by photographing the sea surface and recording the noise caused by the breaking waves. The experimental data will serve for calibration of the theoretical models of the sea surface fraction related to the whitecaps.

15

Application of some echo parameters to the seabed classification - methodological analysis

Tęgowski J., Łubniewski Z.

Hydroacoustics

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2001

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Vol. 4

237--240

EN

The paper presents the methodological analysis of acoustical seabed classification procedure, which aim is to define the most appropriate bottom echo parameters as an input set. Several acoustical and statistical features of echo envelope were compared with morphological features of bottom sediments and a set of parameters was proposed: integral backscattering strength, time of reverberation, radius of autocorrelation, fractal dimension, moment of inertia, and skewness. It was shown using real echoes from seafloor, that this set may be a good descriptor of sea bottom sediments and may be used in classification procedures. In addition, the spatial distribution of echo skewness within Polish Economical Zone of Baltic Sea was presented as an example and compared with sediments allocation map.

16

Sea relation between a sea depth detected by acoustical methods and a nautical depth

Gajewski L., Morgaś W., Relisko J., Tęgowski J.

Oceanological Studies

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2000

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Vol. 29, No. 3

67-84

EN

On twelve testing fields located in the main water basins of the Gdańsk and Szczecin harbours, the efficiency of a new depth technique was verified. The technique that determines a safe nautical depth is defined by a density criterion of a mud-water medium. The measuring results of the medium density varied greatly depending on a physical phenomenon applied in the measuring equipment. The differences found are mainly attributed to a different gas content in the surface mud sediments as well as to reological properties of the sediments. The results of the numerical simulation of acoustic waves propagation in the mud sediments clarify a depth overestimating by the echo sounder of a low frequency.

17

Fractal characterisation of 30 kHz echoes from southern Baltic bottom

Tęgowski J., Łubniewski Z.

Hydroacoustics

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2000

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Vol. 3

15--18

EN

The fractal dimension of 30 kHz echo envelope is used for characterise the bottom sediment type in Southern Baltic Sea. Two methods of the echo waveform fractal dimension calculation were applied: the autocorrelation function log-log slope method and the power spectrum log-log slope method. The results are presented and compared. They show that fractal dimension of echo envelope describes well the bottom sediments morphology and may be used as a significant descriptor in the remote sea bed classification procedures.

18

Acoustic properties of the Pomeranian Bay bottom sediments

Tęgowski J., Klusek Z.

Oceanologia

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1999

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No. 41 (3)

475-487

EN

The properties of bottom backscattered signals in the Pomeranian Bay have been investigated using a one-frequency single beam echosounder working at a central frequency of 30 kHz. The backscattering strength, time of reverberation and attenuation coefficient in sediments were estimated and mapped for the whole area. The other purpose of the investigations was to verify the acoustic one-frequency multiparametric method in order to determine the sediment-type distribution in the Pomeranian Bay. This method was found as useful tool for sediment identification in the study area.

19

Spatial distributions of acoustic field scattered at the sea bottom-numerical model

Tęgowski J.

Hydroacoustics

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1997

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Vol. 1

141--146

EN

The results of the numerical simulation of acoustic wave scattering from rough and attenuating sea bottom are presented. Seattering is studied using ray theory with the main geometry of model taken from Novarini and Caruthers. The distribution of rough surface heights together with bottom acoustical parameters determine the scattered acoustical field properties. Different bottom types with various acoustical parameters have been used in numerical calculations in order to examine the influence of phase shift of reflected signal on scattered acoustical field. Simulation technique was made for surfaces with normal distribution of heights and standard deviation of the surface elevation, 0.01 m. Spatial distribution of the scattered field parameters was determined. Results of calculations for frequencies between 5 and 100 kHz and various bottom parameters are compared.