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• Remote detection of element zonation through plant stress in a geothermal area. • Ag, As, Sb and Ba foliar element zonation maps were retrieved using hyperspectral imaging. • Specific wavelengths attributed to different elements causing plant stress. • Proposed method tested for lab, airborne and satellite hyperspectral remote sensing. 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. [ABSTRACT FROM AUTHOR]

• Point pattern analyses applied to thermal anomalies of a geothermal area. • From which shallow permeability and heat movement are inferred. • Two broad regions can be identified which present distinct subsurface conditions. Geothermal areas are studied with a diversity of techniques, including remote sensing (e.g. hyperspectral and thermal imagery) which can provide a time and cost efficient method to assess the surface of geothermal areas and infer subsurface processes. This study presents the analysis of thermal anomalies extracted from a single thermal infrared image covering Waiotapu Geothermal Field, New Zealand. Point pattern analyses were undertaken to assess any dominant orientations, and departures from randomness based on anomaly locations. The thermal anomalies present orientations that approximately align with nearby active faults, suggesting fault control in the Waiotapu Geothermal Field. Two distinct regions were observed, northern areas and southern areas. Northern areas show higher temperatures (i.e. >47 C°) and lower densities of thermal anomalies, with an orientation close to that of the whole field (∼ N22E°) and separation within cluster separations of ∼250 m, signalling to a high content of clays and proximity to the heat source. Southern areas exhibit lower temperatures (i.e. <47 C°) and a higher density of clustered thermal anomalies in a variety of orientations with clustering at all distances, indicating higher permeability at shallow depths. This is likely caused by a thinner litho-cap layer and a history of hydrothermal eruptions and collapse craters. Thermal imagery can therefore be used to infer the subsurface processes taking place at geothermal areas, elucidating information about the shallow permeability and heat movement. Our method can be applied to any other geothermal field for exploration to understand the shallow substrate and its control on porosity and permeability structure. [ABSTRACT FROM AUTHOR]

Deception Island is amongst the most active volcanoes in the Southern Ocean, with over 20 explosive eruptions in the last ca. 200 years. The eruption that formed the caldera at Deception Island occurred 3980 ± 125 calendar years Before Present, and it is the largest eruptive event documented in Antarctica during Holocene. Since then, post-caldera volcanic activity has comprised many scattered eruptive vents across the island. Mortality of benthic organisms has been reported during the most recent eruptions occurred on the island, in 1967, 1969, and 1970 Common Era (CE), with very low abundances of organisms during the 1967–1973 CE period. Within the sea-flooded part of the caldera depression, named Port Foster, a submarine volcanic axis with several volcanic cones is observed. An interdisciplinary team sampled the best morphologically preserved volcanic edifice within Port Foster, the so-called Stanley Patch. Geophysical data traced the volcano and characterized its morphology and inner structure. Underwater scuba sampling allowed to acquire sediment and rock samples, photographs and video images of the benthic organisms and seascape. Morphology of Stanley Patch cone and textural characteristics of the collected pyroclastic rocks indicate that the volcanic edifice was originated during an explosive eruption. Furthermore, the lack of palagonitization, quenched pyroclast margins, and hyaloclastite deposits indicate that this cone has formed on-land, before the caldera floor became inundated by the seawater, highlighting the complex intra-caldera evolution of Deception Island. A sediment core from the crater was collected for sedimentological, and geochemical analysis. Antarctic climate and seasonal sea ice, together with organic degradation due to high sedimentation rates, explain the low total organic carbon data measured. The volcanic history of the island has probably avoided the development of a stable benthic community over time, similar to other Antarctic shallow communities. Moreover, the current geomorphological conditions still shape different benthic communities than in the surrounding coastal ecosystems. Stanley Patch, and the whole Port Foster, provide a natural laboratory for benchmarking the reestablishment of benthic communities on a volcanic-influenced shallow marine environment, offering relevant data for future studies evaluating global climate change effects on the Antarctic seabed. • Volcanic history shape the background of the benthic communities. • Low TOC and high sedimentation rates structure present communities. • Direct link between disturbance process and benthic composition communities. • Sediment instability boost vagile and opportunistic organisms. [ABSTRACT FROM AUTHOR]