WG 4 « GEOLOGY - GEOPHYSICS »
Composition
Christophe DELACOURT : Institut Universitaire Européen de la Mer UBO/CNRS
Pierre
BRIOLE
: CNRS/INSU Geoscope
Claudie CARNEC
: BRGM
Rémi
MICHEL
: CEA/DASE
Eric
GASTINE
: SOLETANCHE-BACHY SOLDATA
Stéphane BAIZE
: Inst. Radioprotection & Sûreté Nucléaire
Yann
KLINGER
: IPGP
Michel
GAY
: CNRS/Laboratoire des Images et des Signaux
Eliane Cubero-Castan
: CNES
Département de Tectonique
Specificity :
Most of the participants of this WG are at the boundary between
«Thematicians » and « Methodologists » (SAR Interferometry, image
correlation, image processing….).
Thematic domain
Vulcanology :
Seismotectonic: Field that bridges earthquake seismology and plate
tectonics
Cryosphere : The Earth' s cryosphere includes sea ice, freshwater ice,
snow, glaciers, frozen ground and permafrost.
Gravitating Motions
Landslide : rock, earth, or debris flows on slopes due to gravity
Subsidence: Natural and anthropic
Erosion
Our Scientific Objectives :
a) Characterization of various geological structures
b) Surface displacement measurement
c) Monitoring phenomena evolution
d) Understanding of geodynamical or antropic phenomena
e) Modeling and prediction
What we want to do with satellite images :
Imagery of active faults – Seisms
- Faults maps
- Co-seismic and Post-seismic surface displacement maps
- Damage maps
Gravitating Motion
- Detection ; Maps ; Monitoring displacement
Volcanology
- To follow temporal evolution
Subsidence
- Detection ; Monitoring displacement
Erosion Susceptibility
- Erosion rate estimation
Cryosphere
- Glacial lake detection and evolution
- Antartic coastal boundary evolution
- Glaciers evolution (Alps, Himalaya Antartic)
Cartography
DEM
Surface displacement measurements
Links with other WG
Spatial resolution and accuracy need……
Requirements
Domain
Application
Resolution
Erosion
Accuracy
~centimeter to ~decameter
Mass Motions
Cartographie
Glacial lake - Glaciers
~decameter to ~meter
Seismotectonic
Damage
~decameter to ~ few
meters
Erosion
< 0.5 m
Glacial lake - Glaciers
~ decameter
DEM
Mass Motions
Seismotectonic
1cm to 0.5m
~ meter
around 1m
Subsidence
10-3 à 10-2 m
Mass motions
10-3 à 1 m
Post-seismic
10-2 à 10-1 m
Deformation
Volcanology
Glaciers
10-2 à 1 m
Co-seismic
10-1 à 1 m
Coverage needs….
Type
Surface – Nombre de sites
Detection
20% de la France
Monitoring
Few km2 (20 in France)
Application
Mass Motions
Subsidence
15% of France cities
Erosion
~1 ha 500 km2 in France
Seisms
Cartography Archive
1000 km x 10 km
Damage
variable, < 5 sites by year
Displacements
Few km2 – (300km x 10 km)
Lakes
20km x 20km around 10 sites in France
Glaciers
20km x 20km – 100 km x 100 km ; few 10s sites in France
Cryosphere
Volcanoes
< 20 km x 20 km around 100 sites in the world
Temporal resolution needs
Types
Archive
Detection
Temporal
evolution
Applications
Cartography
1 image
Gravitating Motions
3 à 5 every 1 jour during few years
Glaciers
Radar – as frequently as possible
Optical once a year (stereo)
Erosion
Few hours to few tens of hours
Seism
Once a week durin 2 months
Damage
One a week during 1 month
Gravitating Motion
Between once a week and once a year
Volcaoes
variable
Subsidence
Each mont to each two months
Lakes
Each week in summer during crisis
Response time needs :
Applications
Cartography - Detection
Glacier
No major contraints
Slow Gravitating Motions
Seisms
Glacier Lake
Gravitating Motions
Erosion
Volcanoes
As soon as possible during crisis
8 Product sheets
1] Subsidence
2] Erosion
3] Active fault and co-seismic maps
4] Glacial lakes
5] Mass budget on Glaciers
6] Gravitating motions
7] Cartography of damage
8] Monitoring active volcanoes
WG 4 : Required functionalities
Pretreatment geometrical functionalities
Image Stacking : Visible / Visible, Visible / Radar, Radar / Radar
Images Orthorectification
Band X Interferometry
Information extraction functionalities
DEM / DSM
2D an 3D Displacement map processing
Change detection
Change quantification
Semi automatic object recognition (faults, terrace, lakes,..)
Type of data :
Orthorectified images + Displacement map + DEM
Raw data + acquisition parameters
Conclusions
• Main Requirement of WG4 :
- Quantification of change and motion (correlation, DEM’s…)
- No specific requirement for automatic detection of objects (excepted for few
elements : faults, lava flows, glacial lakes…)
- High temporal acquisition in similar orbital conditions
Specific acquisition periods (Glaciers, landslide, volcanoes..)
- Knowledge of radiometric and geometrical parameters of images
(orbitography, image quality…)
- DEM and DSM in natural context with metric spatial resolution and accuracy
- Build up of Archive (Seisms…)
- In case of crisis: reduction of time between request and image download
Thematic WG* work-plan for 2006-2009
Quantification of surface displacement associated to large landslide at the
Reunion Island
High spatial resolution cartography of geological surface and Surface
deformation cartography associated to the Fuyun Area (China)
Possible links with methodological team
Easy use and precise correlation tools…
DEM generation tools on natural context (vegetation, slopes…)