A Unified Framework for Producing CAI Melting, Wark-Lovering Rims and Bowl-Shaped CAIs

Calcium Aluminium Inclusions (CAIs) formed in the Solar System, some 4,567 million years ago. CAIs are almost always surrounded by Wark-Lovering Rims (WLRs), which are a sequence of thin, mono/bi-mineralic layers of refractory minerals, with a total thickness in the range of 1 to 100 microns. Recently, some CAIs have been found that have tektite-like bowl-shapes. To form such shapes, the CAI must have travelled through a rarefied gas at hypersonic speeds. We show how CAIs may have been ejected from the inner solar accretion disc via the centrifugal interaction between the solar magnetosphere and the inner disc rim. They subsequently punched through the hot, inner disc rim wall at hypersonic speeds. This re-entry heating partially or completely evaporated the CAIs. Such evaporation could have significantly increased the metal abundances of the inner disc rim. High speed movement through the inner disc produced WLRs. To match the observed thickness of WLRs required metal abundances at the inner disc wall that are of order ten times that of standard solar abundances. The CAIs cooled as they moved away from the protosun, the deduced CAI cooling rates are consistent with the CAI cooling rates obtained from experiment and observation. The speeds and gas densities required to form bowl-shaped CAIs are also consistent with the expected speeds and gas densities for larger, ~ 1 cm, CAIs punching through an inner accretion disc wall.Comment: 70 pages, 41 figure

Reducing the external environmental costs of pastoral farming in New Zealand: experiences from the Te Arawa lakes, Rotorua

Decades of nutrient pollution have caused water quality to decline in the nationally iconic Te Arawa (Rotorua) lakes in New Zealand. Pastoral agriculture is a major nutrient source, and therefore this degradation represents an external environmental cost to intensive farming. This cost is borne by the wider community, and a major publically funded remediation programme is now under way. This article describes the range of actions being taken to reduce nutrient loads from internal (lake bed sediments) and external (primarily diffuse) sources in the lake catchments. The high economic cost and uncertain efficacy of engineering-based actions to reduce internal nutrient loads is highlighted. Major changes to land management practices to control diffuse nutrient pollution are required throughout New Zealand if the need for costly and lengthy remediation programmes elsewhere is to be avoided. More action to educate farmers and the public about eutrophication issues, development and enforcement of environmental standards, and further consideration of the use of market-based instruments are proposed as ways to correct the current market failure

Reducing the external environmental costs of pastoral farming in New Zealand: experiences from the Te Arawa lakes, Rotorua

Decades of nutrient pollution have caused water quality to decline in the nationally iconic Te Arawa (Rotorua) lakes in New Zealand. Pastoral agriculture is a major nutrient source, and therefore this degradation represents an external environmental cost to intensive farming. This cost is borne by the wider community, and a major publically funded remediation programme is now under way. This article describes the range of actions being taken to reduce nutrient loads from internal (lake bed sediments) and external (primarily diffuse) sources in the lake catchments. The high economic cost and uncertain efficacy of engineering-based actions to reduce internal nutrient loads is highlighted. Major changes to land management practices to control diffuse nutrient pollution are required throughout New Zealand if the need for costly and lengthy remediation programmes elsewhere is to be avoided. More action to educate farmers and the public about eutrophication issues, development and enforcement of environmental standards, and further consideration of the use of market-based instruments are proposed as ways to correct the current market failure

Opening Plenary Speech: Labour Market Trends and Outlook

This paper summarises the Plenary Address from the 15th conference on Labour, Employment and Work in New Zealand. This paper is based on the Ministry of Business, Innovation and Employment’s (The Ministry) Quarterly Labour Market Report, which is a relatively new product that brings together a range of information on the economy and labour market. The first Quarterly Report was released in September 2012

The State of the New Zealand Labour Market

This paper will review recent developments in the New Zealand labour market and trace the passage of these indicators through the global financial crisis to the outlook for the coming 3 years. The paper is based on the Ministry’s Quarterly Labour Market report and Short-term Employment Forecasts. The paper describes a strong labour market. Indicators of labour demand growth have moderated from the elevated levels recorded earlier in 2014, but remain solid. Construction is a significant source of employment demand across the entire country, and not just Canterbury. Migration-led population growth and near-record labour force participation rates are expanding labour supply. Women in general are showing increased involvement in the labour market: the female labour force participation rate returned to its record high of 63.7 per cent (equal to that recorded in March 2014), and the female employment rate (59.7 per cent) is at its highest rate since December 2008. Single mothers in particular have seen a sharp increase in their employment rate, which has reached its highest level since the series began in 1986. High participation is likely slowing the fall in the unemployment rate, which nevertheless hit its lowest level since March 2009. Wage growth remains subdued over the September quarter, but this comes against the backdrop of low inflation