title: Late Quaternary climate variability and change from Aotearoa New Zealand speleothems: Progress in age modelling, oxygen isotope master record construction and proxy-model comparisons

authors: Lorrey, Andrew M.

abstract: We re-evaluated speleothem isotope series from Aotearoa New Zealand that were recently contributed to the Speleothem Isotopes Synthesis and AnaLysis (SISAL) database. COnstructing Proxy Records from Age Models (COPRA) software was used to produce Bayesian age models for those speleothems. The new age modelling helped us examine Late Quaternary temporal coverage for the national speleothem network, and also supported our exploration of three different isotope master record generation techniques using Holocene δ¹⁸O data from Waitomo. We then applied the output from one of the isotope master record techniques to test an application case of how climate transfer functions can be developed using climate model simulated temperatures. Our results suggest Holocene δ¹⁸O trends at Waitomo capture air temperature variations weighted toward the primary season of soil moisture (and epikarst) recharge during winter. This interpretation is consistent with the latest monitoring data from the Waitomo region. Holocene δ¹⁸O millennial-scale trends and centennial-scale variability at Waitomo likely reflect atmospheric circulation patterns that concomitantly vary with surface water temperature and the isotopic composition of the Tasman Sea. A climate model simulation context for the Holocene millennial-scale trends in the Waitomo δ¹⁸O isotope master record suggest that site is sensitive to changes in the subtropical front (STF) and the Tasman Front. Our comparison of isotope master record techniques using Waitomo δ¹⁸O data indicate that caution is needed prior to merging δ¹⁸O data series from different caves in order to avoid time series artefacts. Future work should incorporate more high-resolution cave monitoring and climate calibration studies, and develop new speleothem data from northern and eastern regions of the country.

text: Late Quaternary climate variability and change from Aotearoa New Zealand speleothems: Progress in age modelling, oxygen isotope master record construction and proxy-model comparisons We re-evaluated speleothem isotope series from Aotearoa New Zealand that were recently contributed to the Speleothem Isotopes Synthesis and AnaLysis (SISAL) database. COnstructing Proxy Records from Age Models (COPRA) software was used to produce Bayesian age models for those speleothems. The new age modelling helped us examine Late Quaternary temporal coverage for the national speleothem network, and also supported our exploration of three different isotope master record generation techniques using Holocene δ¹⁸O data from Waitomo. We then applied the output from one of the isotope master record techniques to test an application case of how climate transfer functions can be developed using climate model simulated temperatures. Our results suggest Holocene δ¹⁸O trends at Waitomo capture air temperature variations weighted toward the primary season of soil moisture (and epikarst) recharge during winter. This interpretation is consistent with the latest monitoring data from the Waitomo region. Holocene δ¹⁸O millennial-scale trends and centennial-scale variability at Waitomo likely reflect atmospheric circulation patterns that concomitantly vary with surface water temperature and the isotopic composition of the Tasman Sea. A climate model simulation context for the Holocene millennial-scale trends in the Waitomo δ¹⁸O isotope master record suggest that site is sensitive to changes in the subtropical front (STF) and the Tasman Front. Our comparison of isotope master record techniques using Waitomo δ¹⁸O data indicate that caution is needed prior to merging δ¹⁸O data series from different caves in order to avoid time series artefacts. Future work should incorporate more high-resolution cave monitoring and climate calibration studies, and develop new speleothem data from northern and eastern regions of the country.

year: 2020

title: Offshore petroleum and minerals: Plugging gaps in the present framework

authors: Barton, Barry

subjects: New Zealand

abstract: For twenty years, it has been realized that there is a gap in New Zealand’s environmental law in that there is no general environmental legislation for the exclusive economic zone, and now for the extended continental shelf that includes areas more than 200 nautical miles offshore. The jurisdiction of regional councils under the Resource Management Act 1991 does not extend beyond the 12-mile limit, about 22 km offshore. (The jurisdiction of territorial authorities extends only to the mean low water mark.) That has meant that oil and gas operations beyond the 12-mile limit have not had proper environmental scrutiny. Public concern about such matters has sharpened in the light of petroleum exploration in the Raukumara Basin off the East Cape, although so far it has only reached the stage of seismic exploration. The Deepwater Horizon blowout on the Macondo prospect in the Gulf of Mexico in April 2010 also looms large in public debate. With a lower profile but with a similar potential to cause environmental harm is the possibility of seabed mining operations. A company is gearing up for deep seabed mining off New Britain in Papua New Guinea. Globally, the main targets are cobalt-rich crusts, polymetallic nodules (on the abyssal plain), and massive sulphide deposits (near hydrothermal vents). In New Zealand iron sands are also attractive. Other possible future uses of the offshore are carbon capture and storage and the extraction of gas hydrates. Existing operations such as fishing by bottom trawling present risks of environmental harm to the benthic environment, especially to features such as seamounts. The Minister for the Environment has now announced his intention to introduce a bill to plug this legal gap, at least in relation to petroleum development and seabed mining. Action on this is most welcome. It is desirable to consider the strengths and weaknesses of the proposal, and of the legal framework for oil and gas well drilling in general. Some surprising gaps remain even if the Minister’s proposal is enacted.

text: Offshore petroleum and minerals: Plugging gaps in the present framework For twenty years, it has been realized that there is a gap in New Zealand’s environmental law in that there is no general environmental legislation for the exclusive economic zone, and now for the extended continental shelf that includes areas more than 200 nautical miles offshore. The jurisdiction of regional councils under the Resource Management Act 1991 does not extend beyond the 12-mile limit, about 22 km offshore. (The jurisdiction of territorial authorities extends only to the mean low water mark.) That has meant that oil and gas operations beyond the 12-mile limit have not had proper environmental scrutiny. Public concern about such matters has sharpened in the light of petroleum exploration in the Raukumara Basin off the East Cape, although so far it has only reached the stage of seismic exploration. The Deepwater Horizon blowout on the Macondo prospect in the Gulf of Mexico in April 2010 also looms large in public debate. With a lower profile but with a similar potential to cause environmental harm is the possibility of seabed mining operations. A company is gearing up for deep seabed mining off New Britain in Papua New Guinea. Globally, the main targets are cobalt-rich crusts, polymetallic nodules (on the abyssal plain), and massive sulphide deposits (near hydrothermal vents). In New Zealand iron sands are also attractive. Other possible future uses of the offshore are carbon capture and storage and the extraction of gas hydrates. Existing operations such as fishing by bottom trawling present risks of environmental harm to the benthic environment, especially to features such as seamounts. The Minister for the Environment has now announced his intention to introduce a bill to plug this legal gap, at least in relation to petroleum development and seabed mining. Action on this is most welcome. It is desirable to consider the strengths and weaknesses of the proposal, and of the legal framework for oil and gas well drilling in general. Some surprising gaps remain even if the Minister’s proposal is enacted.

year: 2011

title: Kava and Maaori: New drug fashion or re-engagement with 'kawa'? [Invited presentation]

authors: Aporosa, S. 'Apo'

abstract: It is estimated there are more than 20,000 kava users in New Zealand on an average Friday or Saturday night, with increasing interest and uptake of this indigenous drink by Māori. This presentation argues that some of that increased use of kava by Māori can be interpreted as a cultural expression of pre-migration Hawaiki, rather than simply a new interaction with a foreign drug substance.

text: Kava and Maaori: New drug fashion or re-engagement with 'kawa'? [Invited presentation] It is estimated there are more than 20,000 kava users in New Zealand on an average Friday or Saturday night, with increasing interest and uptake of this indigenous drink by Māori. This presentation argues that some of that increased use of kava by Māori can be interpreted as a cultural expression of pre-migration Hawaiki, rather than simply a new interaction with a foreign drug substance.

year: 2016