Crusta: A new virtual globe for real-time visualization of sub-meter digital topography at planetary scales

Virtual globes are becoming ubiquitous in the visualization of planetary bodies and Earth specifically. While many of the current virtual globes have proven to be quite useful for remote geologic investigation, they were never designed for the purpose of serving as virtual geologic instruments. Their shortcomings have become more obvious as earth scientists struggle to visualize recently released digital elevation models of very high spatial resolution (0.5-1m^2/sample) and extent (>2000km^2). We developed Crusta as an alternative virtual globe that allows users to easily visualize their custom imagery and more importantly their custom topography. Crusta represents the globe as a 30-sided polyhedron to avoid distortion of the display, in particular the singularities at the poles characteristic of other projections. This polyhedron defines 30 ''base patches,'' each being a four-sided region that can be subdivided to an arbitrarily fine grid on the surface of the globe to accommodate input data of arbitrary resolution, from global (BlueMarble) to local (tripod LiDAR), all in the same visualization. We designed Crusta to be dynamic with the shading of the terrain surface computed on-the-fly when a user manipulates his point-of-view. In a similarly interactive fashion the globe's surface can be exaggerated vertically. The combination of the two effects greatly improves the perception of shape. A convenient pre-processing tool based on the GDAL library facilitates importing a number of data formats into the Crusta-specific multi-scale hierarchies that enable interactive visualization on a range of platforms from laptops to immersive geowalls and caves. The main scientific user community for Crusta is earth scientists, and their needs have been driving the development.

[1]  V. Kastelic,et al.  Application of airborne LiDAR to mapping seismogenic faults in forested mountainous terrain, southeastern Alps, Slovenia , 2006 .

[2]  Peter J. Fawcett,et al.  Chronotopographic analysis directly from point-cloud data: A method for detecting small, seasonal hillslope change, Black Mesa Escarpment, NE Arizona , 2007 .

[3]  Ryan Daniel Gold.  Latest Quaternary slip history of the central Altyn Tagh Fault, NW China, derived from faulted terrace risers , 2009 .

[4]  Kenneth W. Hudnut,et al.  High-Resolution Topography along Surface Rupture of the 16 October 1999 Hector Mine, California, Earthquake (Mw 7.1) from Airborne Laser Swath Mapping , 2002 .

[5]  S. Ashford,et al.  Application of Airborne LIDAR for Seacliff Volumetric Change and Beach-Sediment Budget Contributions , 2006 .

[6]  J. L. Bufton,et al.  An airborne scanning laser altimetry survey of Long Valley, California , 2000 .

[7]  M. Favalli,et al.  Lava flow identification and aging by means of lidar intensity: Mount Etna case , 2007 .

[8]  Sagi Filin,et al.  Surface classification from airborne laser scanning data , 2004, Comput. Geosci..

[9]  Ryan D. Gold,et al.  Riser diachroneity, lateral erosion, and uncertainty in rates of strike‐slip faulting: A case study from Tuzidun along the Altyn Tagh Fault, NW China , 2009 .

[10]  Bernd Hamann,et al.  Late Cenozoic deformation of the Kura fold-thrust belt, southern Greater Caucasus , 2010 .

[11]  John Bohannon.  Stalking a Volcanic Torrent , 2007, Science.

[12]  F. Loddo,et al.  Integration of ground-based laser scanner and aerial digital photogrammetry for topographic modelling of Vesuvio volcano , 2007 .

[13]  M. Clark,et al.  The Owens Valley fault zone, eastern California, and surface faulting associated with the 1872 earthquake , 1994 .

[14]  Richard R. Forster,et al.  Accelerating thinning of Kenai Peninsula glaciers, Alaska , 2006 .

[15]  David J. Harding,et al.  High-resolution lidar topography of the Puget Lowland, Washington - A bonanza for earth science , 2003 .

[16]  J. Irish,et al.  Coastal engineering applications of high-resolution lidar bathymetry , 1998 .

[17]  Timothy H. Dixon,et al.  Paleoseismology and Global Positioning System: Earthquake-cycle effects and geodetic versus geologic fault slip rates in the Eastern California shear zone , 2003 .

[18]  Robert E. Holdsworth,et al.  Introduction: Unlocking 3D earth systems—Harnessing new digital technologies to revolutionize multi-scale geological models , 2007 .

[19]  M. Oskin,et al.  Quantifying fault‐zone activity in arid environments with high‐resolution topography , 2007 .

[20]  Mike J. Smith,et al.  Methods for the visualization of digital elevation models for landform mapping , 2005 .

[21]  Robert N. Swift,et al.  Accuracy of airborne laser altimetry over the Greenland ice sheet , 1995 .

[22]  J. C. Savage,et al.  Strain accumulation across the Eastern California Shear Zone at latitude 36°30′N , 2000 .

[23]  K. Gorski,et al.  HEALPix: A Framework for High-Resolution Discretization and Fast Analysis of Data Distributed on the Sphere , 2004, astro-ph/0409513.

[24]  D. Staley,et al.  Surficial patterns of debris flow deposition on alluvial fans in Death Valley, CA using airborne laser swath mapping data , 2006 .

[25]  Jeffrey R. Ridgway,et al.  The development of a deep-towed gravity meter, and its use in marine geophysical surveys of offshore southern California and an airborne laser altimeter survey of Long Valley, California , 1997 .

[26]  E. J. Huising,et al.  Errors and accuracy estimates of laser data acquired by various laser scanning systems for topographic applications , 1998 .

[27]  Yehuda Ben-Zion,et al.  Collective behavior of earthquakes and faults: Continuum‐discrete transitions, progressive evolutionary changes, and different dynamic regimes , 2008 .

[28]  D. J. Chadwick,et al.  Analysis of LiDAR-derived topographic information for characterizing and differentiating landslide morphology and activity , 2006 .

[29]  Ronald J. Hall,et al.  The uncertainty in conifer plantation growth prediction from multi-temporal lidar datasets , 2008 .

[30]  Sridhar Anandakrishnan,et al.  Late Pleistocene slip rate along the Owens Valley fault, eastern California , 2008 .

[31]  Louise H. Kellogg,et al.  Interactive editing of digital fault models , 2010 .

[32]  Amir Sagy,et al.  Evolution of fault-surface roughness with slip , 2007 .

[33]  Louis Moresi,et al.  Role of temperature‐dependent viscosity and surface plates in spherical shell models of mantle convection , 2000 .

[34]  D. Whitman,et al.  Hurricane-induced beach change derived from airborne laser measurements near Panama City, Florida , 2007 .

[35]  Steven N. Bacon,et al.  A 25,000-year record of earthquakes on the Owens Valley fault near Lone Pine, California: Implications for recurrence intervals, slip rates, and segmentation models , 2007 .

[36]  Robert W. King,et al.  Present day kinematics of the Eastern California Shear Zone from a geodetically constrained block model , 2001 .

[37]  Bernd Hamann,et al.  Interactive mapping on 3‐D terrain models , 2006 .

[38]  Lewis A. Owen,et al.  Holocene slip rates along the Owens Valley fault, California: Implications for the recent evolution of the Eastern California Shear Zone , 2001 .

[39]  J. B. Blair,et al.  Quantifying recent pyroclastic and lava flows at Arenal Volcano, Costa Rica, using medium‐footprint lidar , 2006 .

[40]  Eh Tan,et al.  GeoFramework: Coupling multiple models of mantle convection within a computational framework , 2006 .

[41]  Bill Morris,et al.  Identifying structural trend with fractal dimension and topography , 2006 .

[42]  Jan Nyssen,et al.  Use of LIDAR‐derived images for mapping old landslides under forest , 2007 .

[43]  Shuhab D. Khan,et al.  Lidar mapping of faults in Houston, Texas, USA , 2008 .

[44]  Ding Lin,et al.  Variable structural style along the Karakoram fault explained using triple-junction analysis of intersecting faults , 2007 .

[45]  V S Ramachandran,et al.  Perceiving shape from shading. , 1988, Scientific American.

[46]  Laurence C. Smith,et al.  Geomorphic impact and rapid subsequent recovery from the 1996 Skeiðararsandur jokulhlaup, Iceland, measured with multi-year airborne lidar , 2006 .

[47]  Christopher J. Crosby,et al.  Illuminating Northern California's Active Faults , 2009 .

[48]  J. McKean,et al.  Objective landslide detection and surface morphology mapping using high-resolution airborne laser altimetry , 2004 .

[49]  Christophe Voisin,et al.  High resolution 3D laser scanner measurements of a strike‐slip fault quantify its morphological anisotropy at all scales , 2006, 0801.0544.

[50]  R. Holman,et al.  A simple model for the spatially-variable coastal response to hurricanes , 2007 .

[51]  K. L. Frankel,et al.  Characterizing arid region alluvial fan surface roughness with airborne laser swath mapping digital topographic data , 2007 .

[52]  Alex C. Lee,et al.  A LiDAR-derived canopy density model for tree stem and crown mapping in Australian forests , 2007 .

[53]  David J. Harding,et al.  Evidence for Late Holocene Earthquakes on the Utsalady Point Fault, Northern Puget Lowland, Washington , 2004 .

[54]  M. Flood,et al.  LiDAR remote sensing of forest structure , 2003 .