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Visualization of Glacier Surface Movement. Samuel Wiesmann Institute of Cartography, ETH Zurich. Outline. Introduction Existing visualizations Describing the data in geographic data cube Shortcomings and problems Approach Outlook Conclusions. Introduction.
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Visualization of Glacier Surface Movement Samuel Wiesmann Institute of Cartography, ETH Zurich
Outline • Introduction • Existing visualizations • Describing the data in geographic data cube • Shortcomings and problems • Approach • Outlook • Conclusions
Introduction • Visualization of glacier surface movement: • Ice flow: velocities • Changes in ice thickness • Changes in glacier length andice covered area • Mass displacement • (change in shape of crevasses, movement of crevasses, …)
Existing Visualizations • Vector field … along with isotaches [Kääb 2005]
Existing Visualizations • Streamlines and trajectories [NASA SVS 2006/2009] [Kääb 2005]
Existing Visualizations • Velocities: classified and stretched color ramp [Quincey et al. 2009] [Giles et al. 2009]
Existing Visualizations • Color coded velocities with overlain vectors [Bolch et al. 2008]
Existing Visualizations • Velocity vectors and color coded changes in elevation [Kääb 1997/2005]
Existing Visualizations • Dynamic arrows depict flow conditions [NASA SVS 2004/2009]
Existing Visualizations • Movie of 2.5D retreat simulation [Jouvet 2008]
Time specific area, e.g. glacier surface point in time (t1) variables from glacier surface (velocity, height, temperature, …) Space Variable Geographic Data Cube • The principle I adopted from [Bahrenberg et al. 1990], [Maidment et al. 2002]
Time point in time (t1) e.g. velocity Space Variable Geographic Data Cube • The principle II
Time velocity Space direction heights a.s.l. Variable Geographic Data Cube • Situation in a glacier map
Time Space Variable [Kääb 2005] Geographic Data Cube • Type 1: ca. 50% of analyzed visualizations (N=80) • fixed space, 1 point in time, 1 to 4 variables
point in time (t1) point in time (t2) velocity direction heights a.s.l. Geographic Data Cube • The second type I Time Space Variable
point in time (t1) point in time (t2) velocity direction heights a.s.l. Geographic Data Cube • The second type II Time Space Variable
Time Space Variable [NASA SVS 2006/2009] Geographic Data Cube • Type 2: ca. 40% of analyzed visualizations (N=80) • fixed space, 2 (or more) points in time, 1 to 3 variables (whereof 1 at different times)
Time Time Time Space Space Variable Variable Space Variable Geographic Data Cube • Type 1: ca. 50% (N=80) • Type 2: ca. 40% • Type 3: ca. 10%fixed space, time animated, usually 1 variable
Situation summarized • 0% allowing for spatial navigation • 0% allowing for thematic navigation • 10% allowing for temporal navigation (usually start/stop)
[Kääb 1996] Problems which arise • Overlaying symbols when comparing: 1 position (X/Y), 3 values
Problems which arise • Overlaying symbols when comparing: e.g. feature tracking: 4 positions (X/Y), 4 values
[Pritchard et al. 2005] Main problems • Problem of scale • Integration of time
Preprocessing Userweb-browser GIS-Server Approach • Intended system architecture
Outlook I • Testing different visualization techniques • How to improve? • 2D or 3D -- 2D and 3D?
Outlook II • A lot of data from many projects • Usually processed for only one publication • Bundle the data and re-use it!
Outlook III • Compare two glaciers at a certain date • Monitor a glacier over a specific time period • Compare two glaciers over this period of time • Calculate differences • Interpolation • Profiles on-the-fly
Outlook IV • Integration of glacier simulation models • Extract potentially dangerous areas • Resource when estimating potential natural hazards • … and many more …
Conclusions • Glaciology mostly uses “classic” cartography • Bundle the data! • GIS and cartography may provide the platform • Underlying technique exists and is ready to adapt • Improving the visualization and combining tools • More efficient gain of knowledge in glaciology
Thank you for your attention Visualization of Glacier Surface Movement Samuel Wiesmann swiesmann@ethz.ch
Existing Visualizations • Partially dynamic and interactive visualization [Isakowski 2003]
Time Space Variable Data Cube - Time • 1 specific point in time • anywhere in space • any variable
Time Space Variable Data Cube - Space • 1 specific location X/Y/Z • any point in time • any variable
Time Space Variable Data Cube - Variable • 1 specific variable • any point in time • anywhere in space