Sam Thiele

Sam Thiele
Helmholtz-Zentrum Dresden-Rossendorf | HZDR · Institute Freiberg for Resource Technology

PhD

About

60
Publications
39,875
Reads
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1,604
Citations
Introduction
As a geologist I'm fascinated by our wonderfully complex yet amazingly organised planet. I particularly enjoy the challenges earth scientists face when integrating and synthesising diverse and multi-scale datasets. I have a broad range of research interests and skills, including volcanology, digital outcrop acquisition and analysis, remote sensing, three-dimensional modelling and structural mapping. 🌋 www.samthiele.science
Additional affiliations
November 2019 - present
Helmholtz-Zentrum Dresden-Rossendorf
Position
  • PostDoc Position
May 2016 - November 2019
Monash University (Australia)
Position
  • PhD Student
January 2016 - March 2016
Universidad de Colima
Position
  • Volunteer Volcanologist
Education
May 2019 - November 2019
Monash University (Australia)
Field of study
  • Structural Volcanology

Publications

Publications (60)
Article
Full-text available
Hyperspectral imaging is gaining widespread use in the resource sector, with applications in mineral exploration, geometallurgy and mine mapping. However, the sheer size of many hyperspectral datasets (>1 Tb) and associated correction, visualisation and analysis challenges can limit the integration of this technique into time-critical exploration a...
Conference Paper
Full-text available
Hyperspectral imaging methods allow extensive information on rock properties to be captured over large areas (e.g., entire drill cores). While typically interpreted in terms of mineralogy, these data are also sensitive to textural properties like grain size and porosity. In this study, we explore possible links between hyperspectral data and physic...
Conference Paper
We argue that traditional 2D hyperspectral imaging is not adapted to many modern challenges. With the rise of high spatial resolution, hyperspectral sensors mounted on different platforms (e.g. drones, terrestrial, satellites) and innovative applications (e.g. urban mapping, mining monitoring), projections, occlusions, perspective effects and data...
Article
Full-text available
The Puga valley, in Ladakh, contains one of India's most prospective geothermal systems. Substantial geophysical and geochemical research has been conducted to characterise this system, though uncertainties regarding the subsurface reservoir's geometry and permeability structure remain a barrier to its development. In this contribution , we aim to...
Article
Full-text available
The new generation of satellite hyperspectral (HS) sensors provides remarkable potential for regional-scale mineralogical mapping. However, as with any satellite sensor, mapping results are dependent on a typically complex correction procedure needed to remove atmospheric, topographic and geometric distortions before accurate reflectance spectra ca...
Conference Paper
Full-text available
Hyperspectral imaging is gaining widespread use in the resource sector, with applications in mineral exploration, geometallurgy, and mine mapping. However, the sheer size of many hyperspectral datasets (>1 Tb), and associated data correction and analysis challenges, limit the integration of this technique into time-critical exploration and mining w...
Poster
Full-text available
Hyperspectral data is challenging to visualise, especially when working with multiple data cubes from different sensors, acquisition times or covering different subjects (e.g., drill core or sample scanning campaigns). Existing tools are either commercial and closed-source or relatively limited in functionality, especially when working with multipl...
Article
Full-text available
Diagenetic alteration commonly overprints depositional fabrics in carbonate-dominated sediments and impact reservoir quality. Dolomitization is a prevalent diagenetic process observed in subsurface reservoirs that profoundly alters the depositional precursor’s pore network, thereby influencing subsurface storage capacity and fluid flow behavior. Ty...
Article
Full-text available
The increasing use of deep learning techniques has reduced interpretation time and, ideally, reduced interpreter bias by automatically deriving geological maps from digital outcrop models. However, accurate validation of these automated mapping approaches is a significant challenge due to the subjective nature of geological mapping and the difficul...
Article
Space for intruding magma is created by elastic, viscous, and/or plastic deformation of host rocks. Such deformation impacts the geometries of igneous intrusions, particularly sills and dikes. For example, tapered intrusion tips indicate linear-elastic fracturing during emplacement, whereas fluidization of host rocks has been linked to development...
Preprint
Full-text available
The presence of undesired background areas associated with potential noise and unknown spectral characteristics degrades the performance of hyperspectral data processing. Masking out unwanted regions is key to addressing this issue. Processing only regions of interest yields notable improvements in terms of computational costs, required memory, and...
Article
Full-text available
Most large ocean-island volcanoes are gravitationally unstable. Some deform slowly, forming long-lived slumps, while others collapse and generate potentially dangerous debris avalanches. Here we investigate the effect of pervasive dyke networks on edifice instability, using data from La Palma, Spain. Like fibre-reinforced composites, where rigid la...
Conference Paper
Full-text available
The Puga geothermal field, located at ~4400 m elevation within exhumed ultra-high pressure gneisses of the Tso Morari nappe (Ladakh, western Himalayas), presents one of the most prospective high-enthalpy geothermal energy resources in India (GUPTA et al., 1974). It has been extensively characterised with geophysical and hydrogeochemical methods, bu...
Book
Full-text available
The 5th Virtual Geoscience Conference (VGC 2023) is a multidisciplinary forum for researchers in geoscience, geomatics and related disciplines to share their latest developments and applications. The VGC series focuses on novel developments and applications of close range remote sensing methods within the broad field of geoscience research. The V...
Article
Full-text available
The inherent complexity of underground mining requires highly selective ore extraction and adaptive mine planning. Repeated geological face mapping and reinterpretation throughout mine life is therefore routine in underground mines. Hyperspectral imaging (HSI) has successfully been applied to enhance geological mapping in surface mining environment...
Preprint
Full-text available
The increasing use of deep learning techniques has reduced interpretation time and, ideally, reduced interpreter bias by automatically deriving geological maps from digital outcrop models. However, accurate validation of these automated mapping approaches is a significant challenge due to the subjective nature of geological mapping and the difficul...
Article
Full-text available
The analysis of hydrothermal alteration in exploration drill cores allows for fluid–rock interaction processes to be traced, for fluid flow paths to be identified, and thus for vectors in mineral systems to be determined. Hyperspectral imaging techniques are increasingly being employed to fill the scale gap between lab-based petrographic or geochem...
Conference Paper
Full-text available
Diagenetic alteration such as secondary dolomitization cause significant property heterogeneities in reservoirs and pose challenges in reservoir development strategies. Super-k heterogeneities associated with such processes have been reported from super giant reservoirs of Arabia. This study presents a new approach that uses hyperspectral imaging (...
Preprint
Full-text available
There has been a large barrier in geothermal energy production in India due to the knowledge gap in understanding the subsurface uncertainties. In Puga, Ladakh, a significant amount of research has been done that estimates the availability of >5000 MWh of geothermal energy, but it remains untapped. It is largely due to a limited understanding of re...
Chapter
Natural and engineered swarms of hydraulic fractures have been shown to exhibit emergent geometric characteristics. Fracture spacing, in particular, is often observed to be remarkably regular in both continental‐scale dyke swarms and engineered systems. In this contribution we adopt a swarm theory framework for investigating this emergent behavior...
Preprint
Full-text available
The analysis of hydrothermal alteration in exploration drill cores allows to trace fluid-rock interaction processes, identify fluid flow paths and thus determine vectors in mineral systems. Hyperspectral imaging techniques are increasingly being employed to fill the scale gap between lab-based petrographic or geochemical analyses and the typical si...
Conference Paper
Full-text available
In late Jurassic Arab-D reservoirs, diagenetic alteration of depositional fabrics led to the development of distinct dolomite types with highly varying reservoir properties ranging from a flow baffle to “super” k layers. This has added significant complexity beyond depositional heterogeneities to the reservoir architecture. Interpreting the distrib...
Article
Full-text available
Hyperspectral imaging is an innovative technology for non-invasive mapping, with increasing applications in many sectors. As with any novel technology, robust processing workflows are required to ensure a wide use. We present an open-source hypercloud dataset capturing the complex but spectacularly well exposed geology from the Black Angel Mountain...
Article
Full-text available
The Black Angel Zn-Pb ore deposit is hosted in folded Paleoproterozoic marbles of the Mârmorilik Formation. It is exposed in the southern part of the steep and inaccessible alpine terrain of the Rinkian Orogen, in central West Greenland. Drill-core data integrated with 3D-photogeology and hyperspectral imagery of the rock face allow us to identify...
Article
Full-text available
While uncrewed aerial vehicles are routinely used as platforms for hyperspectral sensors, their application is mostly confined to nadir imaging orientations. Oblique hyperspectral imaging has been impeded by the absence of robust registration and correction protocols, which are essential to extract accurate information. These corrections are especi...
Article
Full-text available
Efficient, socially acceptable and rapid methods of exploration are required to discover new deposits and enable the green energy transition. Sustainable exploration requires a combination of innovative thinking and new technologies. Hyperspectral imaging (HSI) is a rapidly developing technology and allows for fast and systematic mineral mapping, f...
Article
Full-text available
The digitization and automation of the raw material sector is required to attain the targets set by the Paris Agreements and support the sustainable development goals defined by the United Nations. While many aspects of the industry will be affected, most of the technological innovations will require smart imaging sensors. In this review, we assess...
Article
Full-text available
The widespread application of drones and associated miniaturization of imaging sensors has led to an explosion of remote sensing applications with very high spatial and spectral resolutions. The 3-D ultrahigh-resolution digital outcrop models created using drones and oblique imagery from ground-based sensors are now commonly used in the academic an...
Article
Full-text available
Field observations and unmanned aerial vehicle surveys from Caldera Taburiente (La Palma, Canary Islands, Spain) show that pre‐existing dykes can capture and re‐direct younger ones to form multiple dyke composites. Chill margins suggest that the older dykes were solidified and cooled when this occurred. In one multiple dyke example, an ⁴⁰Ar/³⁹Ar ag...
Article
Full-text available
Enhanced digital outcrop models attributed with hyperspectral reflectance data, or hyperclouds, provide a flexible, three-dimensional medium for data-driven mapping of geological exposures, mine faces or cliffs. This approach allows the collection of spatially contiguous information on exposed mineralogy and so provides key information for understa...
Preprint
Full-text available
Field observations and unmanned aerial vehicle surveys from Caldera Taburiente (La Palma, Canary Islands, Spain) show that pre-existing dykes can capture and re-direct younger ones to form multiple dyke composites. Chill margins suggest that the older dykes were solidified and cooled when this occurred. In one multiple dyke example, an 40Ar/39Ar ag...
Article
Full-text available
The feedback between dyke and sill intrusions and the evolution of stresses within volcanic systems is poorly understood, despite its importance for magma transport and volcano instability. Long-lived ocean island volcanoes are crosscut by thousands of dykes, which must be accommodated through a combination of flank slip and visco-elastic deformati...
Preprint
Full-text available
The feedback between dyke and sill intrusions and the evolution of stresses within volcanic systems is poorly understood, despite its importance for magma transport and volcano instability. Long-lived ocean island volcanoes are crosscut by thousands of dykes, which must be accommodated through a combination of flank slip and visco-elastic deformati...
Thesis
Full-text available
Dykes are the principal magma transport pathways in many ocean island volcanoes and, after solidification, these intrusions form abundant geomechanical discontinuities. However, their spatial and temporal distribution is poorly understood due to limited exposure in most volcanic environments. As such, their cumulative influence on the magnitude and...
Article
Full-text available
During eruptive activity of andesitic stratovolcanoes, the extrusion of lava domes, their collapse and intermittent explosions are common volcanic hazards. Many lava domes grow in a preferred direction, in turn affecting the direction of lava flows and pyroclastic density currents. Access to active lava domes is difficult and hazardous, so detailed...
Conference Paper
Full-text available
Dykes are the most common means of magma transport in basaltic volcanoes, so knowledge of dyke propagation paths is critical for volcanic hazard analyses. Some dykes contain internal chill margins and/or compositional variation that suggest they formed from two or more temporally separate dyking events. These multiple-dykes have been studied from a...
Article
Full-text available
Measurement of structure orientations is a key part of structural geology. Digital outcrop methods provide a unique opportunity to collect such measurements in unprecedented numbers, and are becoming widely applied. However, orientation estimates produced by plane fitting can be highly uncertain, especially when observed data are approximately coll...
Preprint
Full-text available
Measurement of structure orientations is a key part of structural geology. Digital outcrop methods provide a unique opportunity to collect such measurements in unprecedented numbers, and are becoming widely applied. However, orientation estimates produced by plane fitting can be highly uncertain, especially when observed data are approximately coll...
Article
Full-text available
The advent of large digital datasets from unmanned aerial vehicle (UAV) and satellite platforms now challenges our ability to extract information across multiple scales in a timely manner, often meaning that the full value of the data is not realised. Here we adapt a least-cost-path solver and specially tailored cost functions to rapidly interpolat...
Conference Paper
Full-text available
The island of La Palma (Spain) is well known for large collapse events, the most recent of which removed a significant portion of the Cumbra Nueva edifice at ca. 550 ka. Erosion of this collapse scar has formed extensive cliffs within Caldera de Taburiente, exposing thousands of dykes in an approximately radial swarm. The role of these dykes in the...
Article
Full-text available
Two centuries ago William Smith produced the first geological map of England and Wales, an achievement that underlined the importance of mapping geological contacts and structures as perhaps the most fundamental skill set in earth science. The advent of large digital datasets from unmanned aerial vehicle (UAV) and satellite platforms now challenges...
Article
Full-text available
Structure-from-motion (SfM) algorithms greatly facilitate the generation of 3-D topographic models from photographs and can form a valuable component of hazard monitoring at active volcanic domes. However, model generation from visible imagery can be prevented due to poor lighting conditions or surface obscuration by degassing. Here, we show that t...
Data
Documentation for the CloudCompare plugin which implements our shortest-path based fracture identification tool in a usable fashion. The plugin is now bundled with Cloud Compare (from v. 2.9 alpha)
Conference Paper
Full-text available
UAV-based photogrammetric and LiDAR techniques provide high resolution 3D point clouds and ortho-rectified photomontages that can capture surface geology in outstanding detail over wide areas. Automated and semi-automated methods are vital to extract full value from these data in practical time periods, though the nuances of geological structures a...
Conference Paper
Full-text available
Photogrammetric and structure from motion (SfM) techniques are increasingly being used to monitor active lava domes (e.g. JAMES & VARLEY, 2012, DIEFENBACH et al., 2013). This study applies SfM techniques to digital single lens reflex (DSLR) and thermal images acquired during observation overflights of Volcán de Colima prior to an eruption and assoc...
Article
Full-text available
We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilize the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between m...
Article
Full-text available
We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilise the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between m...

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