Testimonies, photos
L’Aquila (Italy) earthquake: ALOS PALSAR L-band interferometry
01 July 2009
Synthetic Aperture Radar interferometry (InSAR) is a particularly interesting tool whenever aiming at assessing ground deformation phenomena. In this page we show the co-seismic ground surface displacement seen by L-band (~23 cm) ALOS PALSAR data. The PALSAR data, FBS mode (Fine Beam Single Polarisation) are kindly provided by JAXA (Japanese Space Agency) and ESA Earth watching Team. L-band InSAR is of particular interest as the interferometric signal is coherent even on vegetated areas. The L-band results complement c-band ASAR interferometry (next pages) in the understanding of surface displacement of L’Aquila earthquake. ALOS PALSAR data are processed from two distinct adjacent ascending tracks. Data are made available from JAXA and ESA Earth Watching Team @
http://earth.esa.int/ew/earthquakes/Italy_April09/Italy_April09.htm
More seismological info at
http://www.emsc-csem.org/Earthquake/earthquake.php?id=123429
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| ALOS PALSAR Interferogram (02 March 2007 - 22 April 2009). One colour cycle corresponds to ~11.2 cm of surface displacement projected in the line of sight of the satellite (incidence ~34°). here and the .kml file here | ALOS PALSAR Interferogram (03 July 2008 - 21 May 2009). One colourcyclecorresponds to ~11.2 cmof surface displacement projected in the line of sight of the satellite (incidence ~34°). here and the .kml file here |
Contacts :
Panagiotis Elias , for Space Applications and Remote Sensing (Athens, Greece).
Pierre Briole , Ecole Normale Supèrieure de Paris.
Marcello de Michele, French Geological Survey (BRGM).
Daniel Raucoules, French Geological Survey (BRGM).
22 April 2009
InSAR data used to retrieve vertical and horizontal component of surface displacement
InSAR data used to retrieve vertical and horizontal component of surface displacement
Envisat Synthetic Aperture Radar interferometry (InSAR) is used to retrieve vertical and horizontal component of surface co-seismic displacement. We inverted the ENVISAT ASAR data acquired in ascending and descending mode assuming the fault strike is N48W and horizontal component is perpendicular to the fault strike.
Vertical and horizontal component are then used to retrieve an estimate of the fault dip (?). Our preliminary estimates yielded ? ˜ between 51° and 48°.
ENVISAT ASAR data have been promptly made available by the European Space Agency (ESA) Earth watching team:
http://earth.esa.int/ew/earthquakes/Italy_April09/Italy_April09.htm
More seismological info at
http://www.emsc-csem.org/Earthquake/earthquake.php?id=123429
Envisat Synthetic Aperture Radar interferometry (InSAR) is used to retrieve preliminary vertical and horizontal component of surface displacement. Download the image here and the .kml file here and kmz
Contacts :
Pierre Briole , Ecole Normale Supèrieure de Paris.
Marcello deMichele, French Geological Survey (BRGM).
Daniel Raucoules, French Geological Survey (BRGM).
17 April 2009
L'Aquila (Italy) earthquake: ENVISAT ASAR interferometry
Ascending Interferogram
An earthquake Mw 6.3 hit central Italy at 1:32 GMT on the 6 of April 2009. The earthquake struck the Abruzzi region in the vicinity of L'Aquila.
Synthetic Aperture Radar interferometry (InSAR) is a particularly interesting tool whenever aiming at assessing ground deformation phenomena. It allows a regional scale monitoring but also an historical assessment of the deformation by using the existent SAR image archives. ENVISAT Advanced Synthetic Aperture Radar (ASAR) is used to construct an interferogram (combination of two radar images) showing the co-seismic surface deformation in the L'aquila region. The interferogram is then inverted to retrieve a preliminary surface deformation model.
ENVISAT ASAR data acquired on 11 March 2009 and 15 April 2009. Track 129, ascending mode, perpendicular baseline ~250 m. A Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) has been used to model and remove topographic contributionto the interferometric phase.
ENVISAT ASAR data have been promptly made available by the European Space Agency (ESA) Earth watching team:
http://earth.esa.int/ew/earthquakes/Italy_April09/Italy_April09.htm
More seismological info at
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| ENVISAT ASAR ascending mode Interferogram (on 11 March 2009 and 15 April 2009). One colour cycle corresponds to 2.8 cm of surface displacement projected in the line of sight of the satellite (incidence~23°). Download the image here and the .kml file here and kmz | Surface displacement model retrieved by inverting the interferogram against an elastic model. Download the image here and the .kml file here and kmz |
Contacts :
Pierre Briole , Ecole Normale Supèrieure de Paris.
Marcello de Michele, French Geological Survey (BRGM).
Daniel Raucoules, French Geological Survey (BRGM).
16 April 2009
L'Aquila (Italy) earthquake: ENVISAT ASAR interferometry
An earthquake Mw 6.3 hit central Italy at 1:32 GMT on the 6 of April 2009. The earthquake struck the Abruzzi region in the vicinity of L'Aquila.
Synthetic Aperture Radar interferometry (InSAR) is a particularly interesting tool whenever aiming at assessing ground deformation phenomena. It allows a regional scale monitoring but also an historical assessment of the deformation by using the existent SAR image archives. ENVISAT Advanced Synthetic Aperture Radar (ASAR) is used to construct an interferogram (combination of two radar images) showing the co-seismic surface deformation in the L'aquila region. The interferogram is then inverted to retrieve a preliminary surface deformation model.
ENVISAT ASAR data acquired on 01 February 2009 and 12 April 2009. Track 79, descending mode, frame 2745, perpendicular baseline ~150 m. A Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) has been used to modeland remove topographic contribution to the interferometric phase.
ENVISAT ASAR data have been promptly made available by the European Space Agency (ESA) Earth watching team:
http://earth.esa.int/ew/earthquakes/Italy_April09/Italy_April09.htm
More seismological info at
http://www.emsc-csem.org/Earthquake/earthquake.php?id=123429
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| ENVISAT ASAR Interferogram (01 February 2009 - 12 April 2009). One colour cycle corresponds to 2.8 cm of surface displacement projected in the line of sight of the satellite (incidence~23°. Download the image here and the .kml file here and kmz | Surface displacement model retrieved by inverting the interferogram against an elastic model. Download the image here and the .kml file here and kmz |
Contacts :
Pierre Briole , Ecole Normale Supèrieure de Paris.
Marcello de Michele, French Geological Survey (BRGM).
Daniel Raucoules, French Geological Survey (BRGM).