title: Dredge spoil dispersion from an inner shelf dump-mound

authors: Carsten, Harms

subjects: dump-mound

abstract: A study was undertaken on the dispersion of dredge spoil from a dump-mound on the inner shelf in 11-17 m water depth, 3 km offshore from Tauranga Harbour, New Zealand.
Graphic and volumetric analysis of bathymetric changes over the dump-mound and its near vicinity, between 1978 and 1988, showed that based on echo-sounding surveys a high reduction in dump-mound volume occurs in the first two to three years after the dumping. These changes can be explained by high compaction and erosion of the unconsolidated dredge spoil. Between 1980 and 1985 about two thirds of the eroded material accumulate in a semi-circle up to 400 m south of the dump-mound. From 1985 onwards, after about seven years, the dump-mound appears to be stable.
A sea-floor survey was undertaken, including side-scan sonar, sub-bottom seismic profiling, visual observations by underwater-video and SCUBA diving, and remote sediment sampling. It showed the existence of a natural coarse sand facies with wave-generated megaripples (coarse-grained ripples) which is overlain by a lightly rippled to flat fine sand facies. Repeated surveys indicate that the bedforms react to storms. It is suggested that the fine sand blanket is stripped off the coarse sand at places causing a patchy coarse sand distribution. The natural sediment facies distribution at the dump-sites is masked by dumped medium sands from Tauranga Harbour and its ebb tidal delta. Sorting and skewness parameters and pumice content indicate that a lag surface has formed over the dump-site. Natural sediments in the onshore vicinity of the dumpsites have been altered by the deposition of fine sand and pumice after their erosion from the dredge spoil suggesting a general net onshore movement of sediment. The mineralogical similarity of the dredge spoil and the natural inner shelf sediments prevents any larger scale tracing of dredge spoil.
Wave data collected outside of this study indicate that the threshold velocity for fine sand (2 ɸ) over the dump-mound is exceeded 30 - 50 % of the time. Current meter records over a period of 18 days in June 1988 show a weak southerly directed current associated with light onshore and strong offshore winds, and a strong northwest directed alongshore flow during an easterly storm.
Threshold velocities of unidirectional and combined flow (unidirectional flow modified by waves) are rarely exceeded over a rippled bed of fine sand during peak flow. Total boundary shear stresses indicate that stresses induced by waves are increased by the additional effect of currents. The current also provides a directional component to the stress.
It is suggested that low threshold velocities on a gentle slope increase erosion of coarse material from the dump-mound. This material is only transported over a small distance and deposited in a small zone south of the mound. Fine sand and pumice are temporary deposited in the with the fine sand blanket coarse sand facies but eventually mix entering the exchange zone between the inner shelf and beach systems.
No serious environmental impacts of dredge spoil so far. Dumping can be assessed from the dumping of dredge spoil on the inner shelf are not very pumice do not effective for beach remain at the beach nourishment as fine sand and permanently because of their hydraulic difference to the medium sized beach sand.

text: Dredge spoil dispersion from an inner shelf dump-mound A study was undertaken on the dispersion of dredge spoil from a dump-mound on the inner shelf in 11-17 m water depth, 3 km offshore from Tauranga Harbour, New Zealand.
Graphic and volumetric analysis of bathymetric changes over the dump-mound and its near vicinity, between 1978 and 1988, showed that based on echo-sounding surveys a high reduction in dump-mound volume occurs in the first two to three years after the dumping. These changes can be explained by high compaction and erosion of the unconsolidated dredge spoil. Between 1980 and 1985 about two thirds of the eroded material accumulate in a semi-circle up to 400 m south of the dump-mound. From 1985 onwards, after about seven years, the dump-mound appears to be stable.
A sea-floor survey was undertaken, including side-scan sonar, sub-bottom seismic profiling, visual observations by underwater-video and SCUBA diving, and remote sediment sampling. It showed the existence of a natural coarse sand facies with wave-generated megaripples (coarse-grained ripples) which is overlain by a lightly rippled to flat fine sand facies. Repeated surveys indicate that the bedforms react to storms. It is suggested that the fine sand blanket is stripped off the coarse sand at places causing a patchy coarse sand distribution. The natural sediment facies distribution at the dump-sites is masked by dumped medium sands from Tauranga Harbour and its ebb tidal delta. Sorting and skewness parameters and pumice content indicate that a lag surface has formed over the dump-site. Natural sediments in the onshore vicinity of the dumpsites have been altered by the deposition of fine sand and pumice after their erosion from the dredge spoil suggesting a general net onshore movement of sediment. The mineralogical similarity of the dredge spoil and the natural inner shelf sediments prevents any larger scale tracing of dredge spoil.
Wave data collected outside of this study indicate that the threshold velocity for fine sand (2 ɸ) over the dump-mound is exceeded 30 - 50 % of the time. Current meter records over a period of 18 days in June 1988 show a weak southerly directed current associated with light onshore and strong offshore winds, and a strong northwest directed alongshore flow during an easterly storm.
Threshold velocities of unidirectional and combined flow (unidirectional flow modified by waves) are rarely exceeded over a rippled bed of fine sand during peak flow. Total boundary shear stresses indicate that stresses induced by waves are increased by the additional effect of currents. The current also provides a directional component to the stress.
It is suggested that low threshold velocities on a gentle slope increase erosion of coarse material from the dump-mound. This material is only transported over a small distance and deposited in a small zone south of the mound. Fine sand and pumice are temporary deposited in the with the fine sand blanket coarse sand facies but eventually mix entering the exchange zone between the inner shelf and beach systems.
No serious environmental impacts of dredge spoil so far. Dumping can be assessed from the dumping of dredge spoil on the inner shelf are not very pumice do not effective for beach remain at the beach nourishment as fine sand and permanently because of their hydraulic difference to the medium sized beach sand.

year: 1989

title: Ethical relationships between science and society: Understanding the social responsibility of scientists

authors: Small, Bruce Harris

subjects: Ethics

abstract: The wider social responsibility of scientists has received theoretical discussion but little previous empirical research. To elucidate the construct, this thesis investigated scientists’ attitudes, values and beliefs about social responsibility, with a focus on Promethean gene technologies. The thesis articulates a framework for the construct domain and develops and validates a set of new measures related to scientific social responsibility. Five technology fuelled, social and ecological, existential threats to Earth are identified, establishing the need for an increased ethic of social responsibility for the scientific endeavour and scientists in an age of Promethean technologies. The power of developing gene technologies and their social and moral implications are examined, followed by a discussion of relevant normative, meta-ethical and applied ethics theories. Next, Kohlberg’s (1969) cognitive moral development theory, Rest’s (1979) theory of moral behaviour, and Schwartz’s (1992) theory of personal value orientation are discussed as a psychological context for scientific social responsibility. The few empirical studies addressing the issue are reviewed. Original empirical contributions are presented in two studies. Study 1 is an explorative, qualitative research project using face-to-face, in-depth, unstructured interviews to investigate a purposive sample of scientists’ (N = 22) beliefs about the social role of science, and scientists, in research and technology development. The participants all worked in the field of genetic engineering, or studied its social or ecological impacts. From a data-driven, manifest, thematic analysis, three themes emerged, each with several sub-themes: doing public good (sub-themes: benefit/harm, knowledge, technologies, and foresight); engagement (sub-themes: informing society, becoming informed, and integrity) and; compliance (sub-themes: scientific norms, business norms, laws and regulations, societal mores, and personal values). A theoretically-driven, latent, thematic analysis, examined the normative and meta-ethical reasoning underlying participants’ manifest positions. Evidence was found for normative ethical reasoning (i.e., deontological, teleological and virtue ethics) and a range of meta-ethical approaches (i.e., ethical relativism, conventionalism, objectivism, moral absolutism, subjectivism, emotivism, and cultural relativism). From Study 1 items were proposed for two measures of social responsibility based on the first two stages of Rest’s model of moral behaviour. Study 2, a quantitative survey of scientists from six New Zealand Crown Research Institutes (N = 733, 40.9% female), used a nomological network of 39 hypothesised directional relationships (correlations) to help infer construct validity to five new instruments related to social responsibility: moral awareness, moral judgement regarding personal behaviour, technological optimism, attitude to the commercialisation of science, and attitude to the democratisation of science. Five existing instruments also comprised the nomological network: the four Schwartz higher-order value dimensions and a concurrent criterion, general attitude to genetic engineering. Exploratory factor analysis was used to select items for single factor instruments and confirmatory factor analysis to purify the instruments’ dimensionality, followed by reliability analyses. Four new instruments demonstrated good psychometric properties. Twenty-seven of 39 hypothesised correlations were significant in the right direction (at the Bonferroni adjusted p < .001 level), providing initial support for the new instruments’ construct validities and study results regarding participants’ attitudes, beliefs and values towards conducting socially responsible Promethean science.

text: Ethical relationships between science and society: Understanding the social responsibility of scientists The wider social responsibility of scientists has received theoretical discussion but little previous empirical research. To elucidate the construct, this thesis investigated scientists’ attitudes, values and beliefs about social responsibility, with a focus on Promethean gene technologies. The thesis articulates a framework for the construct domain and develops and validates a set of new measures related to scientific social responsibility. Five technology fuelled, social and ecological, existential threats to Earth are identified, establishing the need for an increased ethic of social responsibility for the scientific endeavour and scientists in an age of Promethean technologies. The power of developing gene technologies and their social and moral implications are examined, followed by a discussion of relevant normative, meta-ethical and applied ethics theories. Next, Kohlberg’s (1969) cognitive moral development theory, Rest’s (1979) theory of moral behaviour, and Schwartz’s (1992) theory of personal value orientation are discussed as a psychological context for scientific social responsibility. The few empirical studies addressing the issue are reviewed. Original empirical contributions are presented in two studies. Study 1 is an explorative, qualitative research project using face-to-face, in-depth, unstructured interviews to investigate a purposive sample of scientists’ (N = 22) beliefs about the social role of science, and scientists, in research and technology development. The participants all worked in the field of genetic engineering, or studied its social or ecological impacts. From a data-driven, manifest, thematic analysis, three themes emerged, each with several sub-themes: doing public good (sub-themes: benefit/harm, knowledge, technologies, and foresight); engagement (sub-themes: informing society, becoming informed, and integrity) and; compliance (sub-themes: scientific norms, business norms, laws and regulations, societal mores, and personal values). A theoretically-driven, latent, thematic analysis, examined the normative and meta-ethical reasoning underlying participants’ manifest positions. Evidence was found for normative ethical reasoning (i.e., deontological, teleological and virtue ethics) and a range of meta-ethical approaches (i.e., ethical relativism, conventionalism, objectivism, moral absolutism, subjectivism, emotivism, and cultural relativism). From Study 1 items were proposed for two measures of social responsibility based on the first two stages of Rest’s model of moral behaviour. Study 2, a quantitative survey of scientists from six New Zealand Crown Research Institutes (N = 733, 40.9% female), used a nomological network of 39 hypothesised directional relationships (correlations) to help infer construct validity to five new instruments related to social responsibility: moral awareness, moral judgement regarding personal behaviour, technological optimism, attitude to the commercialisation of science, and attitude to the democratisation of science. Five existing instruments also comprised the nomological network: the four Schwartz higher-order value dimensions and a concurrent criterion, general attitude to genetic engineering. Exploratory factor analysis was used to select items for single factor instruments and confirmatory factor analysis to purify the instruments’ dimensionality, followed by reliability analyses. Four new instruments demonstrated good psychometric properties. Twenty-seven of 39 hypothesised correlations were significant in the right direction (at the Bonferroni adjusted p < .001 level), providing initial support for the new instruments’ construct validities and study results regarding participants’ attitudes, beliefs and values towards conducting socially responsible Promethean science.

year: 2011

title: Location of Te Wahitapu Stream and other possible streams in 1877

authors: de Lange, Willem P.

abstract: Review of evidence to establish, with as much confidence as possible, the path of the Te Wahitapu Stream at Matapouri in 1877. The review also examines if other streams may have been present on or in the vicinity of Te Wahitapu Stream in 1877, and if the 1877 or later tsunami may have latered the course of the boundary stream.

text: Location of Te Wahitapu Stream and other possible streams in 1877 Review of evidence to establish, with as much confidence as possible, the path of the Te Wahitapu Stream at Matapouri in 1877. The review also examines if other streams may have been present on or in the vicinity of Te Wahitapu Stream in 1877, and if the 1877 or later tsunami may have latered the course of the boundary stream.

year: 2009