Lithium-ion batteries (LIBs) are critical for the adoption of electrical vehicles vital for the electrification of road traffic as part of our fossil-fuel phasing out plan. This increasing demand for energy storage has expanded lithium production ten folds over the last 10 years and led to a new debate on the availability of lithium resources as well as sustainable challenges in resource exporting countries.  Batteries manufacturing is not only constrained by the available resources but also limited by the production capacity. However, the global supply chain system is influenced by geopolitical issues, which are affected by the rising resources nationalism and worldwide populism. This study is aimed to improve understanding of the current lithium supply chain system and generate explorative scenarios for lithium future production.  Understand the impact of lithium production on the EU`s energy transition scheme, and challenges and uncertainties within the supply chain system may arise in the light of sustainable development.  Employ quantitative models (logistic function and gompertz functions) to conduct qualitative analysis on inherent assumptions in scenarios. The geographical concentration of lithium resources is a prominent obstacle for expanding the lithium yield in the future due to the marginal diminishing effect and concentration of environmental impact along with the extracting procedure. The supply and demand balance of lithium could engage tight scenarios in the next decades according to our models.  Future production would be limited by the yield capacity in Latin America which holds the most currently known lithium resources. Diversifying lithium sources and expanding hard-rock lithium production would be essential to tackle the surging demand. However, Latin America will dominate lithium production by 2050,  when the current known hard-rock lithium resources turn to deplete. Bolivia holds the largest lithium resources will determine the peak of global lithium production, but hard to see its` influence shortly.   The EU accounts for one-fourth of world lithium consumption with a rather small contribution on the supply chain which also makes it extremely externally dependent. However, it could play an influential role in easing the burden of the global lithium supply chain by extracting lithium resources within its border. Furthermore, local lithium material suppliers can securitize the raw material supply chain of the EU and foster its developing battery and EV industry. From the global perspective, the EU can help with establishing a more responsible supply chain system by participating in the raw material supply chain. This thesis also analyzed how the EU can play a fundamental role in upgrading our global supply chain system and how the EU will get benefits from it.

No description available.

Residents of high-risk flood areas are often unaware and unprepared for extreme flood events. In order to raise awareness and improve preventative measures, methods of communicating the potential hazards, vulnerabilities, and risks associated with flood events need to enhanced. Geovisualizations that incorporate three-dimensional (3D) models of urban environments are being applied more frequently to improve communication of potential flood events to members of the lay-public. Recent studies suggest that the interactive and explorable environments provided by 3D geovisualization tools allow users to visualize complex geospatial data in a manner that is more easily understood than traditional 2D maps. The aim of this study was to examine the use of a 3D model for the purpose of communicating predicted flood levels in residential areas. An exploratory case study was conducted to construct and evaluate a 3D model of previously calculated data from the Testebo River in Gävle, Sweden. Methods for creating the model were developed with information obtained from in-depth literature reviews, and consultations with GIS professionals. To evaluate the communicative ability of the model, usability tests were conducted on a small sample size of participants. Through these processes, an explorable 3D model that represented the 100-year and highest probable flood scenarios in the residential areas of Varva, Strömsbro, Forsby and Stigslund was created. The results of the usability tests indicated the model was an effective visualization and provided appropriate tools for exploration. Although the study identified some limitations of the model and 3D models in general that should be considered, it also provides a valuable foundation on which to develop further studies of 3D models for flood communication purposes along the Testebo River and in other flood-prone areas.

Deep-marine basins linked to active continental margins by sloped ocean-floor profiles commonlyhost the final accumulation of sediment that was eroded and transported from the continents. Thedeep-marine sediment archives preserved in these settings commonly offer the most completerecord of sediment transfer from continents to ocean basins over geologic time scales. This isespecially true in basins associated with regions of active tectonism, where loss or alteration ofsediment source terrains leave submarine basin deposits as the only record of the tectonic and cli-matic forcings that govern the transfer of sediment to the deep basin. The overarching goal of thisdissertation is to evaluate controls on submarine slope and basin-floor sedimentation that considersboth large-scale system drivers and the internal complexities and autogenic processes associatedwith sediment routing systems. In pursuit of this goal, the research presented in this dissertationspans a range of spatial and temporal scales. At the largest scale, the influence of sediment recy-cling is addressed to evaluate how changes in intrabasinal sediment sources reflect phases of basinevolution and what influence recycling of previously deposited basin sediments has on the fidelityof the deep-marine sedimentary record at geologic time scales. At the smaller scale, analysis ofsedimentation units and characterization of sedimentary bodies form the foundation for linkingthe stratigraphic preservation of depositional processes to discrete submarine geomorphic condi-tions. Such a linkage can provide insight into changes in slope gradient and the transition fromsediment transport and bypass to sediment deposition along the slope profile. Thirdly, a detailedinvestigation of deformed slope deposits addresses how depositional processes and stratigraphicstacking of submarine fan deposits influences slope stability. Synthesis across these broad spatialand temporal scales required integration of various tools and data types including: (1) detailedoutcrop measurements, (2) cliff-face correlation and characterization of depositional architecture,(3) geologic mapping, (4) basin-scale correlation, (5) detrital geochronology, and (6) carbonategeochemistry. / Ph. D.

I explore how gender operates to disadvantage women graduate students in the geosciences. My study is framed and supported by three veins of theory which provide insight into how gender operates in often invisible ways to marginalize and exclude women scientists: Joan Acker’s theory of gendered organizations, theory regarding the process of socialization into graduate school, and feminist theory regarding the relationship between women and the sciences. While women vary in the extent to which they see gender bias as impacting their experience in graduate school, there are invisible ways in which gender bias operates to disadvantage women. For example, the expectation held by elite graduate programs that students should avoid taking on responsibilities outside the classroom and lab marginalizes women who have or are interested in having partners or children; due to cultural understandings about what a father’s role in the family should be, the same does not hold true for men. Disadvantages experienced in graduate school may impact women later on in their careers and ultimately lead them to exit the field. I suggest that current messages about the field of geosciences, and the oil & gas industry in particular, may strip women (and men) of a feminist platform from which to combat gender inequality. / text

The context of megadrought, drought more severe than any we have experienced over the past 100 years, is assessed in this dissertation. A set of new climate reconstructions including drought, dustiness, and temperature from the south San Juan Mountains in southern Colorado is presented here and provides unforeseen insights into these unusual events. The global context of megadroughts is also analyzed using a network of reconstructions. The new drought record is from bristlecone tree-rings, spans the last 2000 years, and shows two periods with anomalous aridity and drought in the south San Juan Mountains. The later period corresponds with well-characterized medieval climate anomaly (MCA; 900-1400 AD) aridity in southwestern North America (henceforth the Southwest). The earlier interval coincides with the Roman Period (1-400 AD). A severe drought with, almost 50 consecutive years of below average tree-growth, occurs in the middle of the Roman Period during the 2nd century AD. Assessment of Roman and MCA droughts in the context of global climate reconstructions reveals that similar hemisphere scale circulation patterns during both intervals might have contributed to severe aridity in the Southwest. Next relationships between droughts and pluvials in western North America (henceforth the West) and global sea surface temperature (SST) patterns over the last 1100 years are examined. Several methods are used including teleconnection patterns imbedded in tree-ring reconstructed drought maps, and a global network of SST reconstructions. Teleconnection patterns during droughts and pluvials suggest that megadroughts and pluvials were likely forced in part by sequences of anomalous years in the Pacific and Atlantic Ocean, but the analyses also reveals contradictory results that may require new ways of understanding the relationship between SSTs and drought on long timescales. Next, returning to the south San Juan Mountains, we developed a new dust reconstruction from a lake sediment core. The reconstruction illustrates that dustiness has been an important component of Southwestern climate over the past 2941 years. The record shows high dust deposition in the past especially around 900 BC and during the MCA. High dust deposition before recent land use changes suggests that megadroughts or associated periods of aridity were widespread and severe enough to mobilize dust, perhaps resulting in further reductions to mountain snowpack and stream flow. Finally, a new biomarker based temperature reconstruction is presented. The reconstruction spans the last 2000 years and shows that the warmest temperatures during that interval occurred during the Roman Period and the MCA. The record suggests these periods were warmer than today, indicating the San Juan Mountains are a sensitive region to temperature change. Both past warm periods coincide with anomalous drought and dustiness, suggesting that temperature and dust may have acted as megadrought enhancing feedbacks. In summary, this dissertation helps characterize the timing and causes of southwest North American Megadroughts over the past 2000 years; separately addressing changes in moisture balance, dustiness, temperature, hemispheric circulation, and sea surface temperature forcing patterns during these unusual events.

archives@tulane.edu / 1 / Maricel Beltran Burgos

This dissertation consists of three manuscripts that will be submitted for publication. All three of these examine various aspects of the evolution of the India-Asia suture zone in southern Tibet after the India-Asia collision. Continent-continent collision is one of the basic tectonic plate boundary types, has occurred repeatedly throughout geologic history, and represents one of the principle mechanisms responsible for the formation of high elevation plateaus and orogens. Uplift within these zones has also drastically changed the earth's climate and atmospheric circulation, and erosion from continental collision has resulted in some of the thickest accumulations of sediment in the world (Curray, 1991; Einsele et al., 1996). However, despite the global significance of continental collision, much of the fundamental geodynamic and geologic processes governing these events remain enigmatic. This is the result of several factors. First and foremost, intense deformation and uplift of rocks, often from mid crustal levels, over very short periods of time (Hodges and Silverberg, 1988; Seward and Burg, 2008; Zeitler et al., 2014) results in the erosive removal of much of the geologic record of a collision zone. Second, because the best modern example of continental collision is the Tibet-Himalayan system, the study of continental collision in general has been hampered by high elevations, remoteness, difficult working conditions, and political unrest. The work presented here represents a step toward better understanding the geology, geologic history, and geodynamic evolution of the Tibetan Plateau, the Himalaya, and the India-Asia collision. This has been accomplished through study of two of the post-collisional sedimentary basins which formed near or within the India-Asia suture zone. Appendix A addresses the structure, sedimentology, age, and provenance of the Liuqu Conglomerate. The key conclusions of this section are: 1) The Liuqu Conglomerate was deposited in north flowing, stream dominated alluvial fans. These were located situated in a wedge-top position within a system of north verging thrust faults likely associated with the Great Counter Thrust, and sediment was accommodated via burial beneath thrust structures. 2) The age of the Liuqu Conglomerate has been refined to ~20 Ma based on detrital zircon U-Pb and fission track dating, ⁴⁰Ar/³⁹Ar dating of biotite from a cross-cutting dike, re-analysis of previously published pollen data, regional structural considerations, and oxygen isotope composition of paleosol carbonates. 3) Sand-sized and finer-grained sediment eroded from the southern margin of Asia prior to collision was transported southwards across the Xigaze forearc basin, deposited within the subduction trench, and then accreted within the subduction complex mélange. After collision, this sediment was eroded from the mélange and shed northward into the India-Asia suture zone. Appendix B focuses on the abundant paleosols preserved within the Liuqu Conglomerate. This study uses major element geochemistry of these paleosols and stable isotope analyses of paleosol carbonates to constrain the degree and type of chemical weathering, and thus the paleoclimate and paleoelevation, of the Liuqu Conglomerate. The key conclusions of this paper are: 1) at ~20 Ma, the India-Asia suture zone experienced warm and wet conditions that promoted intense chemical weathering of soils exposed in the inactive portions of alluvial fans. Paleorainfall is estimated at ~1500 mm/yr, and weathering intensity was similar to soils formed in the Neogene Siwalik Group of India, Nepal, and Pakistan, which formed under wet, semitropical, and low elevation conditions. 2) The India-Asia suture zone experienced these conditions at ~20 Ma despite extensive deformation and crustal thickening which has been documented within the Tethyan Himalayan and Himalayan thrust belts. This crustal thickening should have resulted in the (surface) uplift of the entire India-Asia collision zone, and there is evidence that at least some portion of the Himalayan crest was at or near modern elevations by ~17 Ma. Our results require either that the Tethyan Himalaya and India-Asia suture zone were not uplifted despite as much as 40 million years of intense crustal shortening or that these regions attained high elevation prior to ~20 Ma, and then lost elevation around this time before being immediately re-uplifted. The viability of these two scenarios cannot be explicitly tested with the data presented in this chapter; however, based on the data presented in Appendix C, I strongly favor the second scenario. Appendix C focuses on the Kailas Formation, exposed ~20 km north of the Liuqu Conglomerate within the India-Asia suture zone. The Kailas Formation is exposed along ~1300 km of the India-Asia suture zone. For this study, I present new sedimentologic, provenance, and geochronologic data for the Kailas Formation. Key findings of this study are that 1) the Kailas Formation is younger in the center of the suture zone, near 90°E, and becomes progressively older to the west; preliminary data suggest that these rocks are older to the east as well, but additional age constraints are required. 2) The pattern of sedimentation documented for the Kailas Formation is nearly identical to the spatio-temporal pattern of adakitic and ultrapotassic rocks in southern Tibet. These rocks have been attributed to rollback and breakoff of the Indian continental slab. Sedimentation within the Kailas basin has also been attributed to rollback of the Indian slab (DeCelles et al. 2011), and this idea is corroborated by the agreement of the sedimentary and magmatic records. 3) This presents an interesting possibility for explaining the existence of low elevations within the India-Asia suture zone at ~20 Ma, as documented in Appendix B. High elevation topography produced by crustal shortening and thickening likely remained intact until slab rollback and breakoff started around 30 Ma and caused the India-Asia suture zone to experience large scale extension and subsidence. The Kailas Formation was deposited in the resulting basin, which opened first in the west, and propagated eastward. After slab breakoff occurred, contractional deformation would have resumed, and the area would have been quickly uplifted to its modern elevations.

Contemporary observations show an increase in the melting of the Greenland Ice Sheet (GrIS) since the early 21st century. Located near the critical sites of oceanic deep convection and deep water formation, the melting of the GrIS has the potential to directly impact the Atlantic Meridional Overturning Circulation (AMOC) by freshening ocean surface waters in these regions. The majority of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models project a decline in AMOC strength by 10-50% during the 21st century, in response to the increase in atmospheric greenhouse gas (GHG) concentrations. However, due to the simple treatment of polar ice sheets and the lack of a dynamical ice sheet component in these models, these projections likely underestimated the impacts of the GrIS melt, leading to uncertainty in projecting future AMOC evolution and climate change around Greenland. To better understand the impact of the GrIS melt on the AMOC, we perform a series of 21st century projection runs with a state-of-the-art Earth System Model-GFDL ESM2Mb. We consider a medium and a high Representative Concentration Pathway (RCP) scenario (RCP4.5 and RCP8.5, respectively). Unlike the CMIP5-standard RCP runs which included only radiative forcing, the new model experiments are also forced with additional and potentially more realistic meltwater discharge from the GrIS. This meltwater discharge is estimated based on a model-based relationship between the GrIS surface melt and the 500hPa atmospheric temperature anomalies over Greenland. The model simulations indicate that compared to the RCP4.5-only and RCP8.5-only projections, the additional melt water from the GrIS can further weaken the AMOC, but with a relatively small magnitude. The reason is that radiative forcing already weakens the deep convection and deep water formation in the North Atlantic, therefore limiting the magnitude of further weakening of AMOC due to the additional meltwater. The modeling results suggest that the AMOC's sensitivity to freshwater forcing due to the GrIS melt is highly dependent on the location and strength of oceanic deep convection sites in ESM2Mb as well as the pathways of the meltwater towards these regions. The additional meltwater contributes to the minimum surface warming (so-called "warming hole") south of Greenland. These simulations with ESM2Mb contribute to the Atlantic Meridional Overturning Circulation Model Intercomparison Project (AMOCMIP), a community effort between international modeling centers to investigate the impacts of the melting of the GrIS on the AMOC and quantify the associated uncertainty.

The Pampean flat slab subduction in west-central Argentina (latitude 30-33S) and the steeply dipping Northern Costa Rica subduction zone (latitude 9-11N) show significant along-trench variations in both the subducting and overriding plates. This dissertation contains the results of three seismological studies using broadband instruments conducted in these subduction zones, with the aim of understanding the structure of the lithosphere and the correlation between the variability observed in the downgoing and the overriding plates. In the Costa Rica region, by analyzing teleseismic receiver functions we investigate the variability in the hydration state of the subducting Cocos Plate and the nature of three distinct crustal terranes within the overriding Caribbean Plate: the Nicoya and Chorotega terranes that display an oceanic character, and the Mesquito Terrane, which is more compatible with continental crust.In the Pampean region of Argentina, we apply a regional-scale double-difference tomography algorithm to earthquake data recorded by the SIEMBRA (2007-2009) and ESP (2008-2010) broadband seismic networks to obtain high-resolution images of the South America lithosphere. We find that most of the upper mantle has seismic properties consistent with a depleted lherzolite or harzburgite, with two anomalous regions above the flat slab: a higher Vp/Vs ratio anomaly consistent with up to 10% hydration of mantle peridotite and a localized lower Vp/Vs ratio anomaly consistent with orthopyroxene enrichment. In addition, we study the geometry and brittle deformation of the subducting Nazca Plate by determining high-quality earthquake locations, slab contours, and focal mechanisms. Our results suggest that the subduction of the incoming Juan Fernandez Ridge controls the slab geometry and that ridge buoyancy and slab pull are key factors in the deformation of the slab. The spatial distribution of the slab seismicity suggests variability in the hydration state of the subducting Nazca Plate and/or in strain due to slab bending. These observations support the hypothesis that the along-trench variability in bathymetric features and hydration state of the incoming plate has profound effects in the subducting slab geometry and the upper plate structure in both flat and steeply dipping subduction zones.