Browsing by Author "Procter JN"

Now showing 1 - 6 of 6
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    Exploring intrusive processes through the crystal cargo of volcanic rocks: The case of lava flows from Taranaki volcano, New Zealand
    (Elsevier B V, 2024-11) D'Mello NG; Zellmer GF; Ubide T; Caulfield J; Usuki M; Iizuka Y; Kereszturi G; Procter JN; Stewart RB; Romano C
    The present-day edifice of Taranaki volcano, New Zealand, is largely made up of lava flows extruded over approximately the last 8 kyr. The crystal cargo of plagioclase, pyroxene and amphibole in these lavas displays varied major, minor, and trace element zoning patterns, pointing to long and complex crystal growth histories. Crystal zoning patterns do not vary systematically between stratigraphic units, and multiple patterns are seen within the same sample over very short length scales. Intracrystalline elemental variations reveal mineral-melt interactions, which result in repeated resorption and recrystallisation in varied environments. Variable degrees of undercooling are evidenced by clinopyroxenes, with most crystals displaying sector zoning (ΔT < 50 K), while others only show concentric zoning, which suggests very low ΔT. The common occurrence of resorbed cores within the crystals and the prevalence of glomerocrysts indicate antecrystic and/or xenocrystic origins and crystal aggregation processes. We hypothesise that the repeated intrusion of melts into the crustal basement of Taranaki volcano has resulted in the formation of a heterogeneous subsolidus plutonic to supersolidus mushy (∼15–55 vol% crystals) system that interacts with intruding melts from the mantle. These interactions result in disaggregation of crystal clots from the plutonic intrusives and remobilization of the crystals through various sub-environments of small ephemeral mush pockets. Eruption-triggering injections of melt then pick up these crystals with varied growth histories to be extruded
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    Informed geoheritage conservation: Determinant analysis based on bibliometric and sustainability indicators using ordination techniques
    (MDPI (Basel, Switzerland), 2021-05-19) Németh B; Németh K; Procter JN; Zgłobicki W
    Ordination methods are used in ecological multivariate statistics in order to reduce the number of dimensions and arrange individual variables along environmental variables. Geoherit-age designation is a new challenge for conservation planning. Quantification of geoheritage to date is used explicitly for site selection, however, it also carries significant potential to be one of the indicators of sustainable development that is delivered through geosystem services. In order to achieve such a dominant position, geoheritage needs to be included in the business as usual model of conservation planning. Questions about the quantification process that have typically been addressed in geoheritage studies can be answered more directly by their relationships to world development indicators. We aim to relate the major informative geoheritage practices to underlying trends of successful geoheritage implementation through statistical analysis of countries with the highest trackable geoheritage interest. Correspondence analysis (CA) was used to obtain information on how certain indicators bundle together. Multiple correspondence analysis (MCA) was used to detect sets of factors to determine positive geoheritage conservation outcomes. The analysis resulted in ordination diagrams that visualize correlations among determinant variables translated to links between socio‐economic background and geoheritage conservation outcomes. Indicators derived from geoheritage‐related academic activity and world development metrics show a shift from significant Earth science output toward disciplines of strong international agreement such as tourism, sustainability and biodiversity. Identifying contributing factors to conservation‐related de-cisions helps experts to tailor their proposals for required evidence‐based quantification reports and reinforce the scientific significance of geoheritage.
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    Remote exploration and monitoring of geothermal sources: A novel method for foliar element mapping using hyperspectral (VNIR-SWIR) remote sensing
    (Elsevier Ltd, 2023-06) Rodriguez-Gomez C; Kereszturi G; Jeyakumar P; Pullanagari R; Reeves R; Rae A; Procter JN
    Hyperspectral remote sensing is an emerging technique to develop new cost- and time-effective geophysical mapping methods. To overcome challenges introduced by plant cover in geothermal systems globally, we hypothesise that foliage can be used as a proxy to map underlying surface geothermal activity and heat-flux due to their capability on elemental uptake from geothermal fluids and host rock/soil. This study shows for the first time that foliar elemental mapping can be used to image geothermal systems using both high-resolution airborne and satellite hyperspectral images. This study has specifically targeted kanuka shrub (kunzea ericoides var. microflora) as a proxy media to develop air- and spaceborne hyperspectral solutions to monitor inaccessible, biologically and culturally sensitive geothermal areas. Using high resolution airborne AisaFENIX and PRISMA hyperspectral data, foliar element maps for Ag, As, Ba and Sb have been developed using Kernel Partial Least Squares Regression and Random Forest classification models to track their foliar distribution and develop a conceptual model for metal and thermal induced changes in plants. Our study shows evidence that the created foliar element maps are in concordance with independent LiDAR-retrieved canopy structure and height as well as temperature effects of the underlying geothermal field. This study has proven air- and spaceborne hyperspectral sensors can indeed capture critical information within the VNIR and SWIR regions (e.g. ∼452, ∼500, ∼670, ∼820, ∼970, ∼1180, ∼1400 and ∼2000 nm) that can be used to identify metal and thermal-induced spectral changes in plants reliably (overall accuracy of 0.41–0.66) with remotely sensed imagery. Our non-invasive method using hyperspectral remote sensing can complement existing practices for exploration and management of renewable geothermal resources through timely monitoring from air- and spaceborne platforms.
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    Ruapehu and Tongariro stratovolcanoes: a review of current understanding
    (Taylor and Francis Group on behalf of GNS Science Ltd, 2021-05-02) Leonard GS; Cole RP; Christenson BW; Conway CE; Cronin SJ; Gamble JA; Hurst T; Kennedy BM; Miller CA; Procter JN; Pure LR; Townsend DB; White JDL; Wilson CJN
    Ruapehu (150 km3 cone, 150 km3 ring-plain) and Tongariro (90 km3 cone, 60 km3 ring-plain) are iconic stratovolcanoes, formed since ∼230 and ∼350 ka, respectively, in the southern Taupo Volcanic Zone and Taupo Rift. These volcanoes rest on Mesozoic metasedimentary basement with local intervening Miocene sediments. Both volcanoes have complex growth histories, closely linked to the presence or absence of glacial ice that controlled the distribution and preservation of lavas. Ruapehu cone-building vents are focused into a short NNE-separated pair, whereas Tongariro vents are more widely distributed along that trend, the differences reflecting local rifting rates and faulting intensities. Both volcanoes have erupted basaltic andesite to dacite (53–66 wt.% silica), but mostly plagioclase-two pyroxene andesites from storage zones at 5–10 km depth. Erupted compositions contain evidence for magma mixing and interaction with basement rocks. Each volcano has an independent magmatic system and a growth history related to long-term (>104 years) cycles of mantle-derived magma supply, unrelated to glacial/interglacial cycles. Historic eruptions at both volcanoes are compositionally diverse, reflecting small, dispersed magma sources. Both volcanoes often show signs of volcanic unrest and have erupted with a wide range of styles and associated hazards, most recently in 2007 (Ruapehu) and 2012 (Tongariro).
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    The geological history and hazards of a long-lived stratovolcano, Mt. Taranaki, New Zealand
    (Taylor and Francis Group on behalf of the Royal Society of New Zealand, 2021-03-17) Cronin SJ; Zernack AV; Ukstins IA; Turner MB; Torres-Orozco R; Stewart RB; Smith IEM; Procter JN; Price R; Platz T; Petterson M; Neall VE; McDonald GS; Lerner GA; Damaschcke M; Bebbington MS
    Mt. Taranaki is an andesitic stratovolcano in the western North Island of New Zealand. Its magmas show slab-dehydration signatures and over the last 200 kyr they show gradually increasing incompatible element concentrations. Source basaltic melts from the upper mantle lithosphere pond at the base of the crust (∼25 km), interacting with other stalled melts rich in amphibole. Evolved hydrous magmas rise and pause in the mid crust (14–6 km), before taking separate pathways to eruption. Over 228 tephras erupted over the last 30 kyr display a 1000–1500 yr-periodic cycle with a five-fold variation in eruption frequency. Magmatic supply and/or tectonic regime could control this rate-variability. The volcano has collapsed and re-grown 16 times, producing large (2 to >7.5 km3) debris avalanches. Magma intrusion along N-S striking faults below the edifice are the most likely trigger for its failure. The largest Mt. Taranaki Plinian eruption columns reach ∼27 km high, dispersing 0.1 to 0.6 km3 falls throughout the North Island. Smaller explosive eruptions, or dome-growth and collapse episodes were more frequent. Block-and-ash flows reached up to 13 km from the vent, while the largest pumice pyroclastic density currents travelled >23 km. Mt. Taranaki last erupted in AD1790 and the present annual probability of eruption is 1–1.3%.
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    Visitation Rate Analysis of Geoheritage Features from Earth Science Education Perspective Using Automated Landform Classification and Crowdsourcing: A Geoeducation Capacity Map of the Auckland Volcanic Field, New Zealand
    (MDPI (Basel, Switzerland), 2021-11-22) Németh B; Németh K; Procter JN; Jordá Pardo JF
    The increase in geoheritage studies has secured recognition globally regarding the importance of abiotic natural features. Prominent in geoheritage screening practices follows a multicriteria assessment framework; however, the complexity of interest in values often causes decision making to overlook geoeducation, one of the primary facets of geosystem services. Auckland volcanic field in New Zealand stretches through the whole area of metropolitan Auckland, which helps preserve volcanic cones and their cultural heritage around its central business district (CBD). They are important sites for developing tourist activities. Geoeducation is becoming a significant factor for tourists and others visiting geomorphological features, but it cannot be achieved without sound planning. This paper investigates the use of big data (FlickR), Geopreservation Inventory, and Geographic Information System for identifying geoeducation capacity of tourist attractions. Through landform classification using the Topographic Position Index and integrated with geological and the inventory data, the underpromoted important geoeducation sites can be mapped and added to the spatial database Auckland Council uses for urban planning. The use of the Geoeducation Capacity Map can help resolve conflicts between the multiple objectives that a bicultural, metropolitan city council need to tackle in the planning of upgrading open spaces while battling of growing demand for land.