Remnants of a Young Monogenetic Volcanic Field and the Fragile Balance of Anthropogenic Interaction

Abstract

The rapid development of Auckland City in New Zealand from an initial rural settlement to a global urban hub produced a characteristic footprint on the Auckland Volcanic Field (AVF). This process was facilitated by increased anthropogenic activity that has resulted in the deterioration and destruction of many volcanic landforms and caused severe archaeological, cultural, geological and educational losses in an alarmingly short timescale. The AVF has 53 volcanic centres, and of these, 17% are classified as intact, 28% are partially intact, 30% are partially destroyed, and 25% are destroyed (including 13% that have no trace left). Based on surface area, approximately 40% of volcanic deposits in the AVF have been lost. The most common causes for impacts are public land use, quarrying and urban development. Regardless, there is significant potential to be found in the balance between the losses and gains of anthropogenic impacts on volcanic landforms. In the AVF and worldwide, geological studies have often been assisted by the presence of outcrops created by quarrying, mining, transport infrastructure and other modifications of volcanic landforms. Areas of significant volcanic geoheritage worldwide are often linked with these impacted volcanoes, and the information gained from these geoheritage areas assists in the management of geodiversity and geoeducation. Several volcanic centres are currently at risk of further destruction in the near future (Crater Hill, Waitomokia, Maugataketake, Kohuroa, Three Kings, St Heliers and McLaughlins Mt) and should be prioritised for any possible research before it is too late. We propose that a geological assessment should be a requirement before and, if possible, during any land development on or near a volcanic landform. Allowing access to scientists through the course of development in areas with volcanic landforms would, in turn, aid public and governing bodies in decision-making for the future of the city and its volcanoes in terms of increased knowledge of volcanic mechanisms of the AVF and awareness of the potential associated hazards.