@jbrussell @CopernicusEU This is #Etna #volcano, whose eastern flank is slowly moving towards the east as a result of gravitational forces and upwelling of #magma from under the volcano. Magma injection also occur regularly at the volcano summit, feeding #lava flows and #eruptions, further increasing deformation. This is easily visible with #InSAR. See De Novelis et al 2019 paper, which focuses on the Dec 2018 #eruption: https://scholar.google.com/scholar?cluster=8685606862432434928&hl=fr&as_sdt=2005&sciodt=0,5#d=gs_qabs&t=1668609673277&u=%23p%3DUHTlOdd2JJMJ

@RaphaelGrandin @CopernicusEU Very cool, thanks! So in the original image, blue to the east and red to the west would be an inflation signal, correct?

@jbrussell @CopernicusEU Well, in this case, ground motion is a mixture of horizontal and vertical displacement. The #Sentinel1 #satellite, like other #radar (#SAR) satellites, senses motion in its line-of-sight (#LOS), which is oblique (approx 30° away from vertical). Mathematically, the result is a dot product been 3D displacement vector and 3D #LOS vector... which can be positive or negative. So, it's a little bit more complicated, but short answer is "Yes". 🙂