Amit Chourasia

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VISUAL REPRESENTATION OF SEISMIC DATA

• Amit Chourasia
• Visualization Scientist
• Visualization Services
• San Diego Supercomputer Center
• Presented at Geoinformatics 2007, may 18th

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Data Sources

• Observed Sensors, experiments, etc
• Simulated Weather, earthquakes, etc
• Data Attributes
• Time varying
• Multivariate
• Heterogeneous

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Problems

• How to verify and validate ?
• How to analyze and gain scientific insight ?
• How to share information among experts and
  others?

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Understanding Data

• Large amount of numbers dont make much sense to
  humans

• Visual information can encode large amount of
  numbers to gain insight

High
Bandwidth
Low Bandwidth
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Quest for Visual Representation

• Desirable Attributes
• Intuitive
• Highlights feature of interest
• Color Perceptual or Rainbow style?

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Maps

• TeraShake1.3 Spectral Acceleration at 3.0 sec

Collab SCEC
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Self Contouring Technique

• TeraShake1.3 Spectral Acceleration at 3.0 sec

Collab SCEC
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Topography Deformation

• TeraShake2.1 Displacement magnitude

• Puente Hills Simulation

Movie Puente Hills
Collab SCEC
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Cross Sectional

• TeraShake2.1 Velocity Magnitude and Sliprate

Collab SCEC
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Volumetric

• TeraShake 2.2 Velocity-X

Movie TeraShake 2.1
Collab SCEC
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Design Evolution

• TeraShake Aggregate Data 100TB

Collab SCEC
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Multivariate Encoding

• 1906 San Francisco Earthquake Simulation

Movie South Bound
Collab USGS
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Multivariate Encoding

• 1906 San Francisco Earthquake Simulation

Irregular Mesh (36,000 verts, 65,000 tri)
Color Blending
Color Scheme
Collab USGS
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Seven Story Building Shake
Movie Deformation
Collab NEES
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Seven Story Building Shake
Original video Match Check Match
Combined
Perspective npr
Collab NEES
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Tools - SCEC Viz portal
Collab SCEC
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Dirty Data Issues

• Data Formats
• Data Translation
• Data transfer and replication between archival
  and active file systems
• Data larger than available memory

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Lessons Learned (TeraShake)

• In the north-westward propagating rupture
  scenario the wave propagation is strongly guided
  toward the Los Angeles basin after leaving the
  San Andreas Fault (unexpected)
• The sediment filled basin acts as an
  amplification source for trapped waves. A Strong
  amplification is observed in the LA basin long
  after the initial rupture (unexpected)
• Contiguous basins act as energy channels,
  enhancing ground motion in parts of the San
  Gabriel and Los Angeles basins.
• Identification of regions of particularly strong
  shaking
• Validation of input rupture model and instability
  identification
• Observation of star burst patterns in the
  Spectral Amplification maps (unexpected)

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Visualization Issues

• Domain knowledge
• Multivariate data representation design
• Temporal coherence
• Precision Loss (compression, etc)
• Interaction vs. batch visualization
• Perceptual Issues
• Personal Bias (author viewer)

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Information is infinite

• Information overload
• Cant win
• Cant break even
• Cant get out of the game
• Can visual representation help?

Joseph Kielman Science Advisor Dept. of Homeland
Security Comments at VAST2006 Capstone
Think Petascale Data Analysis
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Thanks for your patience? - ?Web
http//visservices.sdsc.edu/email amit_at_sdsc.edu