scholarly journals Halon-1301 – further evidence of its performance as an age tracer in New Zealand groundwater

2017 ◽  
Vol 21 (8) ◽  
pp. 4213-4231 ◽  
Author(s):  
Monique Beyer ◽  
Uwe Morgenstern ◽  
Rob van der Raaij ◽  
Heather Martindale
Keyword(s):  
New Zealand ◽  
Groundwater Age ◽  
Contaminated Sites ◽  
Mixing Models ◽  
Residence Times ◽  
Halon 1301 ◽  
Groundwater Environment ◽  
Groundwater Samples ◽  
Mean Residence Times ◽  
Insight Into

Abstract. We recently discovered a new groundwater age tracer, Halon-1301, which can be used to date groundwater recharged after the 1970s. In a previous study, we showed that Halon-1301 reliably inferred groundwater age at the majority of groundwater sites studied. At those sites, ages inferred from Halon-1301 agreed with those inferred from SF6 and tritium, two reliable widely applied groundwater age tracers. A few samples, however, showed reduced concentrations of Halon-1301, preventing meaningful age interpretation from its concentration. These reduced concentrations were likely a result of degradation or retardation of Halon-1301 in the aquifer. However, we could not provide full evidence for this due to the limited number of groundwater samples analysed (18 in total). In this study, we assess the potential of Halon-1301 as a groundwater age tracer for a larger dataset of groundwater samples under specific groundwater conditions, including highly anoxic young groundwater which can significantly degrade Halon-1301, to gain more information on the magnitude of occurrence and the causes of reduced Halon-1301 concentrations. In this study, we analysed 302 groundwater samples for Halon-1301, SF6, tritium and the CFCs CFC-11, CFC-12 and CFC-113. Comparison of age information inferred from the concentrations of these tracers allows assessment of the performance of Halon-1301 compared to other well established and widely used age tracers. The samples are taken from different groundwater environments in New Zealand and include anoxic and oxic waters with mean residence times ranging from < 2 years to over 150 years (tritium-free). The majority of assessed samples have reduced or elevated concentrations of CFCs, which makes it impossible to infer a reliable age using the CFCs for these samples. Halon-1301, however, reliably infers ages for CFC-contaminated waters. Three other groundwater samples were found to have elevated SF6 concentrations (contaminated). Again, at these SF6-contaminated sites, ages inferred from Halon-1301 agree with ages inferred from tritium. A few samples (14 sites) exhibit reduced concentrations of Halon-1301, which result in elevated inferred Halon-1301 ages in comparison to those inferred from SF6, tritium and/or CFC-113. Assessment of the groundwater environment at these sites gives further insight into the potential causes of Halon-1301 reduction in groundwater. Overall, Halon-1301 gives age information that matches ages inferred from SF6 and/or tritium for the majority (97 %) of the assessed groundwater sites. These findings suggest that Halon-1301 is a reasonably reliable groundwater age tracer, and is in particular significantly more reliable than the CFCs, which may have contamination and degradation problems. Halon-1301 thus has potential to become a useful groundwater age tracer where SF6 and the CFCs are compromised, and where additional independent tracers are needed to constrain complex mixing models.

scholarly journals Halon-1301 – further evidence of its performance as an age tracer in New Zealand groundwater

2017 ◽  
Author(s):  
Monique Beyer ◽  
Uwe Morgenstern ◽  
Rob van der Raaij ◽  
Heather Martindale
Keyword(s):  
New Zealand ◽  
Groundwater Age ◽  
Residence Times ◽  
Halon 1301 ◽  
Groundwater Samples ◽  
Mean Residence Times

Abstract. We recently discovered a new groundwater age tracer, Halon-1301, which can be used to date groundwater recharged after the 1970s. In a previous study, we showed that Halon-1301 reliably inferred groundwater age at the majority of studied groundwater sites. At those sites, ages inferred from Halon-1301 agreed with those inferred from SF6 and tritium, two reliable widely applied groundwater age tracers. A few samples, however, showed reduced concentrations of Halon-1301, preventing meaningful age interpretation from its concentration. These reduced concentrations were likely a result of degradation or retardation of Halon-1301 in the aquifer. However, we couldn’t provide full evidence for this due to the limited number of analysed groundwater samples (18 in total). In this study, we assess the potential of Halon-1301 as a groundwater age tracer for a larger dataset of groundwater samples under specific groundwater conditions, including highly anoxic young groundwater which can significantly degrade Halon-1301, to gain more information on the magnitude of occurrence and the causes of reduced Halon-1301 concentrations. In this study, we analysed 302 groundwater samples for Halon-1301, SF6, tritium and the CFCs CFC-11, CFC-12 and CFC-113. Comparison of age information inferred from the concentrations of these tracers allows assessment of the performance of Halon-1301 compared to other well established and widely used age tracers. The samples are taken from different groundwater environments in New Zealand and include anoxic and oxic waters with mean residence times ranging from

Renewed thinking on groundwater age

2021 ◽  
Author(s):  
Grant Ferguson ◽  
Mark Cuthbert ◽  
Kevin Befus ◽  
Tom Gleeson ◽  
Chandler Noyes ◽  
...  
Keyword(s):  
Environmental Flows ◽  
Numerical Models ◽  
Groundwater Age ◽  
Holistic Approach ◽  
Water Levels ◽  
Residence Times ◽  
Groundwater Sustainability ◽  
Long Time ◽  
Mean Residence Times ◽  
Recharge Rates

&lt;p&gt;Groundwater age and mean residence times have been invoked as measures of groundwater sustainability, with the idea that old or &quot;fossil&quot; groundwater is non-renewable. This idea appears to come from the link between groundwater age and background recharge rates, which are also of questionable use in assessing the sustainability of groundwater withdrawals. The use of groundwater age to assess renewability is further complicated by its relationship with flow system geometry. Young groundwaters near recharge areas are not inherently more renewable than older groundwaters down gradient. Similarly, there is no reason to preferentially use groundwater from smaller aquifers, which will have smaller mean residence times than larger aquifers for the same recharge rate. In some cases, groundwater ages may provide some information where groundwater recharge rates were much higher in the past and systems are no longer being recharged. However, there are few examples where the relationship between depletion and changes in recharge over long time periods has been rigorously explored. Groundwater age measurements can provide insights into the functioning of groundwater flow systems and calibration targets for numerical models and we advocate for their continued use, but they are not a metric of sustainable development. Simple metrics to assess groundwater sustainability remain elusive and a more holistic approach is warranted to maintain water levels and environmental flows.&lt;/p&gt;

scholarly journals Assessment of Halon-1301 as a groundwater age tracer

2015 ◽  
Vol 19 (6) ◽  
pp. 2775-2789 ◽  
Author(s):  
M. Beyer ◽  
R. van der Raaij ◽  
U. Morgenstern ◽  
B. Jackson
Keyword(s):  
Groundwater Age ◽  
Groundwater Resources ◽  
Water Soluble ◽  
Elevated Concentration ◽  
Environmental Tracers ◽  
Halon 1301 ◽  
Gaseous Substance ◽  
Groundwater Samples ◽  
Groundwater Dating ◽  
Age Estimates

Abstract. Groundwater dating is an important tool to assess groundwater resources in regards to their dynamics, i.e. direction and timescale of groundwater flow and recharge, contamination risks and manage remediation. To infer groundwater age information, a combination of different environmental tracers, such as tritium and SF6, are commonly used. However, ambiguous age interpretations are often faced, due to a limited set of available tracers and their individual restricted application ranges. For more robust groundwater dating multiple tracers need to be applied complementarily (or other characterisation methods need to be used to complement tracer information). It is important that additional, groundwater age tracers are found to ensure robust groundwater dating in future. We have recently suggested that Halon-1301, a water soluble and entirely anthropogenic gaseous substance, may be a promising candidate, but its behaviour in water and suitability as a groundwater age tracer had not yet been assessed in detail. In this study, we determined Halon-1301 and inferred age information in 17 New Zealand groundwater samples and various modern (river) water samples. The samples were simultaneously analysed for Halon-1301 and SF6, which allowed for identification of issues such as contamination of the water with modern air during sampling. All analysed groundwater sites had also been previously dated with tritium, CFC-12, CFC-11 and SF6, and exhibited mean residence times ranging from modern (close to 0 years) to over 100 years. The investigated groundwater samples ranged from oxic to highly anoxic. All samples with available CFC data were degraded and/or contaminated in one or both of CFC-11 and CFC-12. This allowed us to make a first attempt of assessing the conservativeness of Halon-1301 in water, in terms of presence of local sources and its sensitivity towards degradation, which could affect the suitability of Halon-1301 as groundwater age tracer. Overall we found Halon-1301 reliably inferred the mean residence time of groundwater recharged between 1980 and 2014. Where direct age comparison could be made 71% of mean age estimates for the studied groundwater sites were in agreement with ages inferred from tritium and SF6 (within an uncertainty of 1 standard deviation). The remaining (anoxic) sites showed reduced concentrations of Halon-1301 along with even further reduced concentrations of CFCs. The reason(s) for this need to be further assessed, but are likely to be caused by sorption or degradation of the compounds. Despite some groundwater samples showing evidence of contamination from industrial or agricultural sources (inferred by elevated CFC concentrations), no sample showed a significantly elevated concentration of Halon-1301, which suggests no local anthropogenic or geologic sources of Halon-1301 contamination.

scholarly journals Using a Soil Chronosequence to Identify Soil Fractions for Understanding and Modeling Soil Carbon Dynamics in New Zealand

Radiocarbon ◽  
2007 ◽  
Vol 49 (2) ◽  
pp. 1093-1102 ◽  
Author(s):  
Christine A Prior ◽  
W Troy Baisden ◽  
Frank Bruhn ◽  
Jason C Neff
Keyword(s):  
New Zealand ◽  
Residence Times ◽  
Turnover Rates ◽  
Mineral Association ◽  
Soil Carbon Dynamics ◽  
Soil Chronosequence ◽  
Grazed Pasture ◽  
Mean Residence Times ◽  
Initial Results ◽  
Pool Sizes

We are developing practical methodologies to characterize pool sizes and residence times for fractions of soil organic matter (SOM) using radiocarbon, with a particular focus on SOM in New Zealand pasture soils that responds to global change on decadal timescales. As single mean residence times for the entire SOM pool can be misleading or uninterpretable, we focus on the use of samples collected about 7 and 40 yr after the bomb14C spike to separate SOM into at least 2 pools. These results from a box model methodology yield sensible estimates of the proportion of “passive” SOM, and the residence time of the dominant pool with approximately decadal residence times. These results are supported by chemical analysis. Approximately 45-yr residence times of light-fraction SOM in a relatively infertile soil contrast with ∼16-yr residence times in a more fertile soil, and correspond to large differences in the proportion of lignin- and polysaccharide-derived SOM in these soils measured using pyrolysis-GC/MS. To achieve greater detail and assess the degree to which “active” SOM with annual turnover rates may bias results from the simple model, we use density as a means of isolating SOM with different degrees of mineral association. Initial results from grazed pasture soils sampled in 2003–4 emphasize that isolating non-mineral-associated light fractions can improve understanding, but may be less important than identifying fractions associated with unique mineralogy. In this soil, a fraction with density ≥2.55 g/mL shows much larger proportions of passive SOM than other fractions.

scholarly journals Assessment of Halon-1301 as a groundwater age tracer

2015 ◽  
Vol 12 (1) ◽  
pp. 1397-1436
Author(s):  
M. Beyer ◽  
R. van der Raaij ◽  
U. Morgenstern ◽  
B. Jackson
Keyword(s):  
Groundwater Age ◽  
Groundwater Resources ◽  
Water Soluble ◽  
Elevated Concentration ◽  
Environmental Tracers ◽  
Halon 1301 ◽  
Gaseous Substance ◽  
Groundwater Samples ◽  
Groundwater Dating ◽  
Age Estimates

Abstract. Groundwater dating is an important tool to assess groundwater resources in regards to their dynamics, i.e. direction and time scale of groundwater flow and recharge, to assess contamination risks and manage remediation. To infer groundwater age information, a combination of different environmental tracers, such as tritium and SF6, are commonly used. However, ambiguous age interpretations are often faced, due to a limited set of available tracers and their individual restricted application ranges. For more robust groundwater dating multiple tracers need to be applied complementarily and it is vital that additional, groundwater age tracers are found to ensure robust groundwater dating in future. We recently suggested that Halon-1301, a water soluble and entirely anthropogenic gaseous substance, may be a promising candidate, but its behaviour in water and suitability as a groundwater age tracer had not yet been assessed in detail. In this study, we determine Halon-1301 and infer age information in 17 New Zealand groundwaters and various modern (river) water samples. The samples are simultaneously analysed for Halon-1301 and SF6, which allows identification of issues such as contamination of the water with modern air during sampling. Water at all analysed groundwater sites have also been previously dated with tritium, CFC-12, CFC-11 and SF6, and exhibit mean residence times ranging from modern (close to 0 years) to over 100 years. The investigated groundwater ranged from oxic to highly anoxic, and some showed evidence of CFC contamination or degradation. This allowed us to make a first attempt of assessing the conservativeness of Halon-1301 in water, in terms of presence of local sources and its sensitivity towards degradation etc., which could affect the suitability of Halon-1301 as groundwater age tracer. Overall we found Halon-1301 reliably inferred the mean residence time of groundwater recharged between 1980 and 2014. Where direct age comparison could be made 71% of mean age estimates for the studied groundwater sites were in agreement with ages inferred from tritium and SF6 (within ± 2 years). The remaining (anoxic) sites showed reduced concentrations of Halon-1301 along with even further reduced concentrations of CFCs. The reason(s) for this need to be further assessed, but are likely to be caused by sorption or degradation of the compounds. Despite some groundwater samples showing evidence of contamination from industrial or agricultural sources via elevated CFC concentrations, no sample indicated significantly elevated concentration of Halon-1301, which may indicate a lack of local anthropogenic or geologic sources of Halon-1301 contamination.

Locking down behavioural compliance: The role of emotion and emotion regulation in breaches of COVID-19 mitigation measures in Aotearoa New Zealand

2021 ◽  
pp. 135910532110299
Author(s):  
Terise Broodryk ◽  
Kealagh Robinson
Keyword(s):  
Public Health ◽  
Young Adults ◽  
New Zealand ◽  
Health Behaviours ◽  
Mitigation Measures ◽  
Aotearoa New Zealand ◽  
High Knowledge ◽  
The Cost ◽  
Insight Into

Although anxiety and worry can motivate engagement with COVID-19 preventative behaviours, people may cognitively reframe these unpleasant emotions, restoring wellbeing at the cost of public health behaviours. New Zealand young adults ( n = 278) experiencing nationwide COVID-19 lockdown reported their worry, anxiety, reappraisal and lockdown compliance. Despite high knowledge of lockdown policies, 92.5% of participants reported one or more policy breaches ( M  = 2.74, SD = 1.86). Counter to predictions, no relationships were found between anxiety or worry with reappraisal or lockdown breaches. Findings highlight the importance of targeting young adults in promoting lockdown compliance and offer further insight into the role of emotion during a pandemic.

Newsmaking criminology in Australia and New Zealand: Results from a mixed methods study of criminologists’ media engagement

2019 ◽  
Vol 53 (1) ◽  
pp. 84-101 ◽  
Author(s):  
Mary Iliadis ◽  
Imogen Richards ◽  
Mark A Wood
Keyword(s):  
New Zealand ◽  
News Media ◽  
The United States ◽  
Mixed Methods Study ◽  
The Past ◽  
Professional Duty ◽  
The Subject ◽  
Survey Responses ◽  
Insight Into ◽  
Newsmaking Criminology

‘Newsmaking criminology’, as described by Barak, is the process by which criminologists contribute to the generation of ‘newsworthy’ media content about crime and justice, often through their engagement with broadcast and other news media. While newsmaking criminological practices have been the subject of detailed practitioner testimonials and theoretical treatise, there has been scarce empirical research on newsmaking criminology, particularly in relation to countries outside of the United States and United Kingdom. To illuminate the state of play of newsmaking criminology in Australia and New Zealand, in this paper we analyse findings from 116 survey responses and nine interviews with criminologists working in universities in these two countries, which provide insight into the extent and nature of their news media engagement, and their related perceptions. Our findings indicate that most criminologists working in Australia or New Zealand have made at least one news media appearance in the past two years, and the majority of respondents view news media engagement as a professional ‘duty’. Participants also identified key political, ethical, and logistical issues relevant to their news media engagement, with several expressing a view that radio and television interviewers can influence criminologists to say things that they deem ‘newsworthy’.

Century plus journeys: using career crafting to explore the career success of pioneer women accountants

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohini P. Vidwans ◽  
Rosalind H. Whiting
Keyword(s):  
New Zealand ◽  
Great Britain ◽  
Organizational Support ◽  
Career Success ◽  
Design Methodology ◽  
Content Type ◽  
The Usa ◽  
Political Economic ◽  
Pioneer Women ◽  
Insight Into

PurposeThe purpose of this study is to explore the struggle for entry and career success of the early pioneer women accountants in Great Britain and its former colonies the USA, Canada, Australia and New Zealand.Design/methodology/approachA career crafting matrix guides the analysis of historical information available on five pioneer women accountants in order to understand their success in gaining entry into the profession and their subsequent careers.FindingsDespite an exclusionary environment, career crafting efforts coupled with family and organizational support enabled these women to become one of the first female accountants in their respective countries. Their struggles were not personal but much broader—seeking social, political, economic and professional empowerment for women.Originality/valueThis is the first paper to utilize the career crafting matrix developed from current female accountants' careers to explore careers of pioneering female accountants. It adds to the limited literature on women actors in accounting and may provide insight into approaching current forms of difference and discrimination.

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