MONITORING THE 2018 ERUPTION OF KĪLAUEA VOLCANO USING VARIOUS REMOTE SENSING TECHNIQUES

Monitoring the regions that are prone to natural hazards is essential in disaster management to provide early warnings. Airborne and space-borne remote sensing techniques are cost-effective in accomplishing this task. Interferometric Synthetic Aperture Radar (InSAR) is an advanced remote sensing technique used to detect and measure the changes in the Earth’s topography over time. Spaceborne InSAR is a precise (~mm accuracy) way to measure the land surface altitudinal changes. Persistent Scatterer Interferometry (PSI) is a powerful method of differential SAR interferometry that processes the InSAR data by automatically selecting the persistent scatterers in the region. In this thesis, I developed a new algorithm to estimate the areal coverage and volume of newly erupted lava by integrating the space-borne InSAR, thermal infrared, Light Detection and Ranging (LiDAR), and Normalized Difference Vegetation Index (NDVI) techniques. I applied this algorithm to the eruption of the East Rift Zone (ERZ) of the Kīlauea volcano that took place between May and August 2018 as a case study, and estimated the areal coverage and volume of lava erupted. I compared the results of InSAR to those derived from airborne LiDAR. I found that although air-borne LiDAR provides data with higher resolution and accuracy, InSAR is almost as good as LiDAR in monitoring deformed areas and has larger spatial and temporal coverage. I also performed the PSI analysis using the Stanford Method for Persistent Scatterers (StaMPS) algorithm, and determined the Line-of-Sight (LOS) deformations prior, during, and after the 2018 eruption of the Kīlauea volcano. Results from the PSI processing show regional subsidence on the Big Island, indicating the deflation of the southern and western part of the Big Island during the eruption at the East Rift Zone. Keywords: Kilauea

Monitoring and modelling volcanoes with assessment of their hazards by means of remote sensing and analogue modelling

Many active volcanoes in developing countries are poorly-known and not monitored. This thesis investigates low cost solutions to map the topography, to identify hazards and to document the eruptions at volcanoes with satellite data. Using a combination of remote sensing techniques and analogue modelling, this thesis also contributes to the understanding of volcanic processes such as the controls upon the 3D shape of sub-volcanic intrusive systems, upon the location of eruption outbreaks, upon the variations in eruption intensity through time and upon the transition between contrasted eruptive styles at a single volcano. After reviewing previous applications of low cost remote sensing in volcanology, the accuracy of two topographic datasets derived from contrasted remote sensing data (ASTER and SRTM) is assessed for volcanic terrains. Oldoinyo Lengai, a natrocarbonatite stratovolcano in Tanzania, is used as an illustrative example of poorly-known volcanoes whose hazards need to be assessed and whose eruptive activity has to be monitored. Satellite images enable mapping, constraining volumes and characterizing surface features of three flank collapses and their associated deposits. An existing numerical model is applied to constrain the emplacement dynamics and the velocity of one of those debris avalanche flows. An algorithm is then presented to retrieve daily information about eruptive activity and its variation over an 8-year period using nighttime MODIS satellite data. Analysis of this time series enable to highlight the control of Earth tides on the timing of high intensity eruptions. The same algorithm, combined with field data and petrologic analyses, is used to document a voluminous lava flow eruption that occurred at Oldoinyo Lengai at the end of March 2006, providing insights into the structure of the shallow plumbing system of the volcano. Satellite data are finally combined with laboratory experiments simulating magma propagation in the Earth crust with sand and syrup or gelatin and water, to provide a better understanding of the control exerted by volcanic edifice load upon magma ascent. These experiments also enable to explain the links between magma ascent, volcano load, sub-volcanic intrusions, volcano surface deformation and location of volcanic vents at the base of large volcanoes

New GPS Time Series Analysis and a Simplified Model to Compute an Accurate Seasonal Amplitude of Tropospheric Delay

Horizontal and vertical deformation of the Earth’s crust is due to a variety of different geophysical processes that take place on various spatiotemporal scales. The quality of the observations from spaced-based geodesy instruments such as Global Positioning System (GPS) and differential interferometric synthetic aperture radar (DInSAR) data for monitoring these deformations are dependent on numerous error sources. Therefore, accurately identifying and eliminating the dominant sources of the error, such as troposphere error in GPS signals, is fundamental to obtain high quality, sub-centimeter accuracy levels in positioning results. In this work, I present the results of double-differenced processing of five years of GPS data, between 2008 and 2012, for sparsely distributed GPS stations in southeastern Ontario and western Québec. I employ Bernese GPS Software Version 5.0 (BSW5.0) and found two optimal sub-networks which can provide high accuracy estimation of the position changes. I demonstrate good agreement between the resulted coordinate time series and the estimates of the crustal motions obtained from a global solution. In addition, I analyzed the GPS position time series by using a complex noise model, a combination of white and power-law noises. The estimated spectral index of the noise model demonstrates that the flicker noise is the dominant noise in most GPS stations in our study area. The interpretation of the observed velocities suggests that they provide an accurate constraint on glacial isostatic adjustment (GIA) prediction models. Based on a deeper analysis of these same GPS stations, I propose a model that accurately estimates the seasonal amplitude of zenith tropospheric delay (ZTD) error in the GPS data on local and regional spatial scales. I process the data for the period 2008 through 2012 from eight GPS stations in eastern Ontario and western Québec using precise point positioning (PPP) online analysis available from Natural Resource Canada (NRCan) (https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ppp.php). The model is an elevation-dependent model and is a function of the decay parameter of refractivity with altitude and the seasonal amplitude of refractivity computed from atmospheric data (pressure, temperature, and water vapor pressure) at a given reference station. I demonstrate that it can accurately estimate the seasonal amplitude of ZTD signals for the GPS stations at any altitude relative to that reference station. Based on the comparison of the observed seasonal amplitudes of the differenced ZTD at each station and the estimates from the proposed model, it can provide an accurate estimation for the stations under normal atmospheric conditions. The differenced ZTD is defined as the differences of ZTD derived from PPP at each station and ZTD at the reference station. Moreover, I successfully compute a five-year precipitable water vapor (PWV) at each GPS site, based on the ZTD derived from meteorological data and GPS processing. The results provide an accurate platform to monitor long-term climate changes and inform future weather predictions. In an extension of this research, I analyze DInSAR data between 2014 and 2017 with high temporal and spatial resolution, from Kilauea volcano in Hawaii in order to derive the spatial and temporal pattern of the seasonal amplitude of ZTD. I propose an elevation-dependent model by the data from a radiosonde station and observations at a surface weather station for modeling the seasonal amplitudes of ZTD at any arbitrary elevation. The results obtained from this model fit the vertical profile of the observed seasonal amplitude of ZTD in DInSAR data, increasing systematically from the elevation of the DInSAR reference point. I demonstrate that the proposed model could be used to estimate the seasonal amplitude of the differenced ZTD at each GPS station within a local network with high accuracy. The results of this study concluded that, employing this model in GPS processing applications eliminates the need for the meteorological observations at each GPS site

Monogenetic basaltic edifices: their architecture, volcanology and importance in hydrocarbon basins

Flood basalt provinces host significant hydrocarbon reserves. The provinces are produced during fissure eruptions which construct volcanic edifices atop an erupting dyke. The edifices are important components of volcanic-affected hydrocarbon basins; they provide insights into the underlying structural and magmatic plumbing systems, as well as acting as fluid migration pathways after burial. Furthermore, the edifices host a wealth of volcanological evidence that can be used to derive information relating to eruption dynamics such as eruption column height, mass flux and duration; as well as providing insights into the effects of eruptions on the environment. However, the location of the fissures in many hydrocarbon basins is poorly constrained. Furthermore, few studies have characterised the internal architecture of the edifices produced during fissure eruptions. This thesis uses field, seismic and well data to characterise the architecture of monogenetic basaltic edifices and understand their temporal and spatial evolution. Field studies along a dissected Holocene fissure, Northeast Iceland, reveal that a scoria-agglutinate cone, spatter ramparts and a scoria rampart were constructed during Hawaiian-style lava fountaining. These edifices are analogous to those formed in the 1783 Laki eruption. Data gathered in this study can be used to recognise fissure-derived edifices in other volcanic provinces. I then contrast these dyke-fed edifices with rootless cones; a morphologically similar volcanic edifice produced during explosive interaction between inflating pāhoehoe lava and unconsolidated sediment. This thesis reveals that rootless cones can be distinguished from dyke-fed edifices on the basis of their juvenile clast morphology and clast density. This allows us to better recognise dyke-proximal locations. Lastly, I use exceptional quality 3D seismic and well data to show how a series of submarine monogenetic volcanoes evolved; progressing from a maar-forming stage, to a pillow volcano and tuff-cone-building stage as the confining pressure decreased above the growing edifices. These insights allow us to distinguish volcanic edifices from similar non-volcanic edifices in other seismic data sets, and also indicates that our understanding of submarine volcanism has previously been biased towards recognition of constructional features

Unravelling the kinematic evolution of segmented rift systems

Normal fault systems within incipient rifts comprise an array of small-­‐scale structures, including networks of fractures and small displacement faults (<15 m) that represent the incremental strains that develop during rift propagation. To constrain the evolution of volcanic rift systems, I investigate rift-­‐fault propagation and localisation at a range of scales using laboratory-­‐based mechanical characterisation of host rocks, and high-­‐resolution structural mapping of faults, and fault-­‐related deformation in an incipient (Koa’e fault system, Hawai’i), and evolved (Krafla fissure swarm, Iceland) rift system. Experimental analysis of pahoehoe lava from Kilauea’s south flank, Hawai’i, highlight a distinctive physical and mechanical stratigraphy related to the volume, and geometry, of voids within the lava. The resulting variability in intact strength produces the effect of a multi-­‐layered sequence within a single lava, and will exert significant control on the segmentation and linkage of initial cracks (mm-­‐scale or less) that develop. High-­‐ resolution mapping of the distribution, geometry, and kinematics of cm-­‐ to km-­‐scale extensional strains in the Koa’e fault system (Hawai’i) and the Krafla fissure swarm (Iceland) also reveals evidence for segmented fault propagation, linkage and non-­‐coaxial strain. This segmentation is a function of the varying natural mechanical anisotropy of the deforming sequence and non-­‐uniform strain rates. Results from the Koa’e and Krafla rifts are compared with break-­‐up related deformation from the NE Atlantic margins to model the evolution of non-­‐coaxial fault sets at the margin scale. Fault and intrusion data from the Faroe Islands and East Greenland highlights geometrically and kinematically comparable structural sets, implying an analogous kinematic evolution of inter-­‐rift strains. I infer that stress transfer during NE Atlantic opening took place by sub-­‐basin scale ancillary faults and dikes, associated with two overlapping, active rift systems in the Paleogene – a NE-­‐propagating Reykjanes ridge, and a SW-­‐ propagating Aegir ridge – rather than via transfer fault segmentation

Unravelling the kinematic evolution of segmented rift systems

Normal fault systems within incipient rifts comprise an array of small-­‐scale structures, including networks of fractures and small displacement faults (<15 m) that represent the incremental strains that develop during rift propagation. To constrain the evolution of volcanic rift systems, I investigate rift-­‐fault propagation and localisation at a range of scales using laboratory-­‐based mechanical characterisation of host rocks, and high-­‐resolution structural mapping of faults, and fault-­‐related deformation in an incipient (Koa’e fault system, Hawai’i), and evolved (Krafla fissure swarm, Iceland) rift system. Experimental analysis of pahoehoe lava from Kilauea’s south flank, Hawai’i, highlight a distinctive physical and mechanical stratigraphy related to the volume, and geometry, of voids within the lava. The resulting variability in intact strength produces the effect of a multi-­‐layered sequence within a single lava, and will exert significant control on the segmentation and linkage of initial cracks (mm-­‐scale or less) that develop. High-­‐ resolution mapping of the distribution, geometry, and kinematics of cm-­‐ to km-­‐scale extensional strains in the Koa’e fault system (Hawai’i) and the Krafla fissure swarm (Iceland) also reveals evidence for segmented fault propagation, linkage and non-­‐coaxial strain. This segmentation is a function of the varying natural mechanical anisotropy of the deforming sequence and non-­‐uniform strain rates. Results from the Koa’e and Krafla rifts are compared with break-­‐up related deformation from the NE Atlantic margins to model the evolution of non-­‐coaxial fault sets at the margin scale. Fault and intrusion data from the Faroe Islands and East Greenland highlights geometrically and kinematically comparable structural sets, implying an analogous kinematic evolution of inter-­‐rift strains. I infer that stress transfer during NE Atlantic opening took place by sub-­‐basin scale ancillary faults and dikes, associated with two overlapping, active rift systems in the Paleogene – a NE-­‐propagating Reykjanes ridge, and a SW-­‐ propagating Aegir ridge – rather than via transfer fault segmentation

Seismic Stratigraphy and Geomorphology of Palaeocene Volcanic Rocks, Faroe-Shetland Basin

2D and 3D seismic reflection data in the Faroe-Shetland Basin have been used to remotely study buried, large-scale Palaeocene volcanic structures emplaced during continental flood basalt volcanism in the Faroe-Shetland Basin. The flood basalts were emplaced as thick and extensive pāhoehoe lava flows from multiple sources, including fissure systems close to the Faroese shelf and from volcanic centres within the basin. This thesis has investigated the distribution and internal structure of the flood basalts based on the hypothesis that volcanic eruptions produce volcanic depositional successions that record the temporal and spatial variations of the basin into which they are emplaced. Multiple eruptions will produce cycles of volcanic deposition that are delineated by hiatal surfaces. These successions can be recognised in seismic reflection data by applying seismic stratigraphic concepts in order to gain insights into the evolution of volcanic basin-fill. The Faroe-Shetland Basin contains a variety of depositional environments, including a deepening marine basin where continental flood basalts reached a palaeo-shoreline and constructed an extensive lava-fed delta system >1000 m thick. The delta is composed of 13 seismic reflection units whose stacking architecture primarily records variations in lava supply and accommodation. Modification of the delta front was by erosion and debris avalanches. The second environment is subaerial to shallow marine where the continental flood basalts emplaced multiple lava flows 10 - 60 m thick which coalesced to form extensive and overlapping lava flow fields. Four seismic reflection units have been recognised and record variations in source and supply of the lava flows. During reoccurring periods of volcanic quiescence, fluvial channels 350 – 500 m wide incised across the lava flow fields, constrained by flow field topography. The volcanic depositional successions used to reconstruct the volcanic basin-fill history of the Faroe-Shetland Basin indicate that eruptive styles and volcanic structures varying significantly over relatively small areas (tens of km2). Many of the seismic observations have been compared to outcrop analogues, are scale-independent and are indicative of emplacement environment. Analysis has also led to the development of a volcanic seismic stratigraphic model as depositional patterns produced during volcanic activity are primarily driven by volcanic supply. The results presented in this thesis have many important implications for stratigraphy, hydrocarbon exploration and basin modelling in the Faroe-Shetland Basin and therefore can be applied beyond the fields of volcanology or seismic interpretation

Seventh Annual V. M. Goldschmidt Conference

Topics considered include: Subduction of the Aseismic Cocos Ridge Displaced Magma Sources Beneath the Cordillera de Talamanca, Costa Rica; Topography of Transition Zone Discontinuities: A Measure of 'Olivine' Content and Evidence for Deep Cratonic Roots; Uranium Enrichment in Lithospheric Mantle: Case Studies from French Massif Central; Rare-Earth-Element Anomalies in the Decollement Zone of the nankai Accretionary Prism, Japan: Evidence of Fluid Flow?; Rare Earth Elements in Japanese Mudrocks: The Influence of Provenance; The Evolution of Seawater Strontium Isotopes in the Last Hundred Million Years: Reinterpretation and Consequences for Erosion and Climate Models; From Pat to Tats: The Lead Isotope Legacy in the Studies of the Continental Crust-Upper Mantle System; Geochronology of the Jack Hills Detrital Zircons by Precise Uranium-Lead Isotope-Dilution Analysis of Crystal Fragments; Iridium in the Oceans; The Helium-Heat-Lead Paradox; Control of Distribution Patterns of Heavy Metals in Ganga Plain Around Kanpur Region, India, by Fluvial Geomorphic Domains; Geochemical and Isotopic Features of Ferrar Magmatic Provience (Victoria Land, Antarctica); Rare Earth Elements in Marine Fine-Grained Sediments from the Northwestern Portuguese Shelf (Atlantic); Aspects of Arc Fluxes; General Kinetic Model for Dolomite Precipitation Rate with Application to the Secular History of Seawater Composition; High-Precision Uranium-series Chronology from Speleothems; Trace-Element Modeling of Aqueous Fluid-Peridotite Interaction in the Mantle Wedge of Subduction Zones; Rainfall Variations in Southeastern Australia over the Last 500,000 Years from Speleothem Deposition; The Role of Water in High-Pressure Fluids; The Kinetic Conditions of Metamorphic Minearogenesis: Evidence from Minerals and Assemblages