Discrete Surface Modeling Based on Google Earth: A Case Study

Google Earth (GE) has become a powerful tool for geological, geophysical and geographical modeling; yet GE can be accepted to acquire elevation data of terrain. In this paper, we present a real study case of building the discrete surface model (DSM) at Haut-Barr Castle in France based on the elevation data of terrain points extracted from GE using the COM API. We first locate the position of Haut-Barr Castle and determine the region of the study area, then extract elevation data of terrain at Haut-Barr, and thirdly create a planar triangular mesh that covers the study area and finally generate the desired DSM by calculating the elevation of vertices in the planar mesh via interpolating with Universal Kriging (UK) and Inverse Distance Weighting (IDW). The generated DSM can reflect the features of the ground surface at Haut-Barr well, and can be used for constructingthe Sealed Engineering Geological Model (SEGM) in further step.Comment: Proceedings of IEEE Conference, ICCSNT 2012, in Pres

Google Earth® Models with COLLADA and WxAzygy® Transparent Interface: An example from Grotto Creek, Front Ranges, Canadian Cordillera

Virtual globes represent a paradigm shift for geoscience education. It is now possible to explore real world experiences across the entire Earth, the Moon, and Mars, and also to combine multiple 2-D images into one 3-D image with topography. Models viewed in Google Earth® are more intuitive for visualizing 3-D geological structures than traditional paper maps and cross-sections. Here a student-constructed geological map and cross-sections from an introductory field school are used to illustrate the creation of a draped geological map over topography. A custom vertical slider elevates the cross-sections above topography and a horizontal slider restores thrust faulting. Models located in situ in topography are made queryable via a ‘cut-away’ using the WxAzygy® transparent interface.SOMMAIRE La notion de « globes virtuels » constitue un changement de paradigme dans le domaine de l’éducation en géoscience. Il est maintenant possible de traiter de la réalité de tous les recoins de la Terre, de la lune et de Mars, et aussi de combiner de multiples images 2-D en une image 3-D affichant la topographie. Les modèles de Google Earth® permettent une visualisation 3-D plus intuitive des structures géologiques que ne le permettent les cartes papiers usuelles et les coupes. Dans la présente, une carte géologique et une coupe réalisées par un étudiant d’un cours d’introduction au travail de terrain sont utilisées pour illustrer la confection d’une carte géologique appliquée sur la topographie correspondante. Un curseur vertical personnalisé dessine les coupes au-dessus de la topographie, et un curseur horizontal permet de restaurer les failles de chevauchement. Ces modèles ancrés au droit de la topographie peuvent être exploiter au moyen d’un écorché produit par l’interface transparent WxAzygy®

Visualizing and Understanding Tectonism and Volcanism on Earth and Other Terrestrial Bodies

This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of the planetary surface, including long volcanic island chains, deep ocean basins, and plate boundary triple junctions. Better understanding of these processes by visualization and numerical modeling is one of the primary goals of this study. In the geospatial analysis lab at ODU, our research methodology starts with the creation of visualizations for teaching. These include Google Earth-based virtual field explorations enhanced with digitized specimens and emergent geological and geophysical cross sections. We test these in classes with IRB compliance and sometimes this leads to the discovery of tectonic research questions which we then explore. Settings studied in this investigation are Tonga Trench in the western Pacific Ocean, Artemis on Venus, the Hawaiian-Emperor seamount chain, and the Azores triple junction. Some of these cases pose specific geophysical problems that were selected for further study. The Tonga Trench is a subduction zone that includes trench rollback and opening of a marginal basin—the Lau Basin. The rollback process is difficult to imagine, and therefore we created a set of instructional resources using COLLADA models and the Google Earth Application Programming Interface (API). Animated models for the assessments tests and exploration of different initiations of the subduction process led to a new alternative hypothesis for rollback. Virtual field explorations required the development of new interface features for the Google Earth API. All these instructional materials were combined into modular multi-user virtual field trip experiences and were subject to IRB-compliant evaluation of learning outcomes. Animated COLLADA models for the Hawaii Islands and Emperor Seamounts helped explain the origin and time progression of the island chain. From seismic data, a three-dimensional reconstruction of the Hawaiian mantle plume was created raising the question of the horizontal advection of the plume conduit in the mantle and its correlation with the change in trend of the islands. The Hawaiian–Emperor chain on Earth is spread out as the Pacific plate is moving over the Hawaiian mantle plume. On Venus, however, the Artemis structure was able to grow to super-plume size due to the absence of plate motion. For Venus, visualization was done on a much larger scale, including cross sections of the whole plate showing large plume structures, and Magellan SARS imagery of surface features. In the Azores triple junction, dispersion of plume material is influenced by plate boundary geometry, creating anomalies in seafloor geophysical data for several hundred kilometers away from the plume center. To explore the interaction between a mantle plume and a plate boundary triple junction, a series of three dimensional finite element numerical models was calculated. A parameter space investigation changed the location of the plume conduit and its volume flux, as well as the treatment of viscosity. Flow patterns, dynamical topography, relative crustal thickness variations and waist width scaling relationships resulting from these calculations give valuable insight into the importance of triple junction configuration in the dispersion of plume material

Exploring the Reasons for the Seasons Using Google Earth, 3D Models, and Plots

Public understanding of climate and climate change is of broad societal importance. However, misconceptions regarding reasons for the seasons abound amongst students, teachers, and the public, many of whom believe that seasonality is caused by large variations in Earth\u27s distance from the Sun. Misconceptions may be reinforced by textbook illustrations that exaggerate eccentricity or show an inclined view of Earth\u27s near-circular orbit. Textbook explanations that omit multiple factors influencing seasons, that do not mesh with students\u27 experiences, or that are erroneous, hinder scientifically valid reasoning. Studies show that many teachers share their students\u27 misconceptions, and even when they understand basic concepts, teachers may fail to appreciate the range of factors contributing to seasonal change, or their relative importance. We have therefore developed a learning resource using Google Earth, a virtual globe with other useful, weather- and climate-related visualizations. A classroom test of 27 undergraduates in a public research university showed that 15 improved their test scores after the Google Earth-based laboratory class, whereas 5 disimproved. Mean correct answers rose from 4.7/10 to 6/10, giving a paired t-test value of 0.21. After using Google Earth, students are helped to segue to a heliocentric view

Modeling, Visualizing, and Understanding Complex Tectonic Structures on the Surface and in the Sub-Surface

Plate tectonics is a relatively new theory with many details of plate dynamics which remain to be worked out. Moving plates can interact by divergence, lateral sliding, convergence, or collision. At a convergent plate boundary, a lithospheric slab of oceanic crust and upper mantle is subducted at a trench and dips down under a magmatic arc — either oceanic or continental. Textbooks show a static view of convergent boundaries but plate dynamics require that subduction zones and magmatic arcs must migrate with time. Therefore I develop animated models to help convey this motion. Also, convergent plate boundaries cannot continue along strike or down dip indefinitely without changing. Subduction zones change orientation and eventually terminate. They may bend and shear or tear and open a window for asthenospheric flow. Two different convergent plate boundaries are the primary focus of my studies: the Tonga subduction zone where the Pacific plate moving beneath an island arc is torn along the Samoan Island Archipelago, and the Andean subduction zone in central South America where the Nazca plate moves beneath a continental arc. I choose these zones because they exhibit tears or shears, where subduction stops, or changes dip suddenly. To examine these features I use several modeling and visualization techniques. COLLADA (COLLabrative Design Activity) models in Google Earth and Google Earth Application Programming Interface (API) are used for visualizing and teaching of plate boundary systems. The testing of COLLADA models for geoscience concepts showed positive learning gains. Kinematic models are made to study strain rates and possible methods of plate evolution. Dynamic COMSOL numerical models are created to probe temperature and flow fields in the subduction zone. Animated COLLADA models are designed for different models of subduction initiation and development for the Tonga trench for both research and educational purposes. The development of these models led to a new hypothesis of this region\u27s formation. Using these models and Google Earth materials studies in undergraduate classes tested the effectiveness of Google Earth based lab activities for enhancing student understanding of geoscience. In the central Andean subduction zone, emergent COLLADA models are made from mining GeoMapApp (http://www.geomapapp.org) and published contour data to demonstrate the unique geometry of the Nazca plate having adjacent subduction angles of 10° and 30°. This led to the research question, can theNazca plate support this geometry by shearing without tearing? A literature review shows efforts to explore this topic by means of hypocenter, teleseismic, and thermal data to have no consensus on the topic. To this end a new approach is taken to examine this region by applying the methods of kinematic and dynamic modeling to further explore this question. These different models of the Andean system lead to the conclusion that no major magmatic window could have opened between the fiat and steep subduction areas given the time and deformation mechanisms available

Virtual Globes for UAV-based data integration: Sputnik GIS and Google Earth™ applications

“This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Digital Earth on 03 May 2018, available online: https://www.tandfonline.com/doi/abs/10.1080/17538947.2018.1470205"The integration of local measurements and monitoring via global-scale Earth observations has become a new challenge in digital Earth science. The increasing accessibility and ease of use of virtual globes (VGs) represent primary advantages of this integration, and the digital Earth scientific community has adopted this technology as one of the main methods for disseminating the results of scientific studies. In this study, the best VG software for the dissemination and analysis of high-resolution UAV (Unmanned Aerial Vehicle) data is identified for global and continuous geographic scope support. The VGs Google Earth and Sputnik Geographic Information System (GIS) are selected and compared for this purpose. Google Earth is a free platform and one of the most widely used VGs, and one of its best features its ability to provide users with quality visual results. The proprietary software Sputnik GIS more closely approximates the analytical capacity of a traditional GIS and provides outstanding advantages, such as DEM overlapping and visualization for its disseminationThis work was supported by Xunta de Galicia under the Grant “Financial aid for the consolidation and structure of competitive units of investigation in the universities of the University Galician System (2016-18)” (Ref. ED431B 2016/030 and Ref. ED341D R2016/023). The authors also acknowledge support provided by “Realización de vuelos virtuales en las parcelas del proyecto Green deserts LIFE09 / ENV/ES / 000447”S

Discipline-Based Planetary Education Research and Computational Fluid Dynamics Analysis of Mars

This thesis originates from the testing and implementation of an IRB-approved interactive animation designed to help students understand what causes The Reasons For The Seasons (RFTS) on Earth. Results from the testing indicated a small improvement in student understanding after exposure to the animation. Next, using the 3-D mapping tool Google Earth, students explored seasons and other planetary features on Mercury, Venus, the Moon and Mars through IRB-approved interactive tours which were developed and tested for astronomy education. Results from the tests indicated that there were statistically significant learning gains (p-value \u3c 0.05) after students interacted with the tours compared to those who did not. The development of the tours inspired a geophysics study of the possibility of former plate motion (or plate tectonics) on Mars. A 2-D finite element convection model for the mantle of Mars was designed and solved using COMSOL Multiphysics 5.1, to investigate whether or not thermal gradients in a Mars-sized planet could cause vigorous upper mantle convection, consistent with plate tectonic processes. Results from this project indicated that stable convection could occur in the interior of a Mars-like planet assuming the presence of sufficiently high thermal gradients at about 0.8 times the mantle temperature of Earth. The convective patterns resembled hot upwelling and cool downwelling which may be similar to subduction-like features. Furthermore, increasing the temperature of the hot boundaries resulted in faster, more rigorous convective motions and a hotter average temperature

Customising virtual globe tours to enhance community awareness of local landscape benefits

Our wellbeing depends upon the services provided by ecosystems and their components. Despite recent advances in academic understanding of ecosystem services, and consideration in UK national environmental policy, a greater awareness is needed at community and individual levels. Dynamic features of virtual globe applications have considerable potential for helping convey the multi-dimensional context of ecosystem services and promoting general awareness. In a case study targeting residents in a small urban fringe river catchment in Norfolk, UK, representatives from local authorities and responsible agencies collaborated with scientists to produce extensive customisation of virtual globes in this context. By implementing a virtual flight over the catchment, different views and scales are traversed to set the context for landscape features and ecosystem services. Characteristic sites, e.g. supplying cultural services, are displayed and relationships with the natural environment are explained using linked on-screen text. Implementation is cost-effective and described for practitioners in ecosystem and landscape management, who may be inexperienced in landscape visualisation. Supplied as three pre-packaged virtual tours, products are made available for download and are publicised at a variety of engagement events, including teaching events with schoolchildren. The tours have attracted public interest and generated positive feedback about improving knowledge of local natural assets. Schoolchildren show confidence with the interface, but supplementary problem-based activities can improve learning opportunities. The capacity of virtual globes to support more participatory involvement of the public in local ecosystem management may increase in the future, but such visualisations can already help promote community awareness of local landscape benefits