Santorini volcano: new data of deformation during 2011-2012

According to the latest seismic and satellite (InSAR and GPS) data, the uplift at the Santorini volcano (2011-2012) has has come to an end.
In a recent press release, the Institute for Astronomy, Astrophysics, Space Applications & Remote Sensing and the Dionysos Satellite Observatory, published their results of follow up studies in Santorini with the collaboration of MIT.
For the first time, the severe deformation (more than 10 cm in some areas) that mainly affected Nea Kameni and the northeastern caldera during 2011-early 2012, has been accurately quantified using advanced remote sensing techniques (PSI and SBAS) with satellite data and extended geodetic measurements (cGPS).




from the press release
"The volcanic unrest began in January 2011 and diminished around the end of February 2012. These results are documented in a manuscript in press [Papoutsis et al., 2013] at Geophysical Research Letters. An early view of the work can be found in onlinelibrary.wiley.com/doi/10.1029/2012GL054137/abstract, published online on 26 of January 2013.

"In Papoutsis et al. [2013] the surface deformation associated with Santorini volcanic activity is measured with the use of Envisat ASAR data and the application of two well-established Interferometric Synthetic Aperture Radar techniques, namely Persistent Scatterer Interferometry and Small BAseline Subset, producing dense line-of-sight (LOS) ground deformation maps depicting uplift with a radially decaying pattern in amplitude and velocity from the center of
deformation.
"These can be seen in the fi gure that follows, where the maximum inflation of 150mm/yr, an unprecedent magnitude for Santorini since quantitative monitoring of the area began, is observed at Nea Kameni (a resurgent dome within the caldera), and in Imerovigli and Fira in Thera island (northeast of Nea Kameni) - well known touristic destinations.

"It is concluded fi nally in Papoutsis et al. [2013] that InSAR and the latest seismic and GPS data, spanning up to December 2012, suggest that the rapid inflation episode ceased since the end of February 2012. The observed displacement has declined signi cantly, reaching more than 80mm/yr of velocity change in certain sites. These observations are possibly signaling a new phase of relative stability and reducing the probability of an imminent volcanic eruption, following empirical knowledge from calderas that experienced similar inflation episodes in the past.

References
- Andrew V. Newman, Stathis Stiros, Lujia Feng, Panos Psimoulis, Fanis Moschas, Vasso Saltogianni, Yan Jiang, Costas Papazachos, Dimitris Panagiotopoulos, Eleni Karagianni, and Domenikos Vamvakaris (2012) "Recent geodetic unrest at Santorini Caldera, Greece" Geophysical Research Letters, 39(6):L06309, 2012. ISSN 0094-8276. doi: 10.1029/2012GL051286
- Ioannis Papoutsis, Xanthos Papanikolaou, Mike Floyd, Kang Hyeun Ji, Charalampos Kontoes, Demitris Paradissis, and Vangelis Zacharis (2013) "Mapping inflation at Santorini volcano, Greece, using GPS and InSAR." Geophysical Research Letters, 2013. ISSN 1944-8007. doi: 10.1029/2012GL054137.
- Michelle M. Parks, Juliet Biggs, Philip England, Tamsin A. Mather, Paraskevi Nomikou, Kirill Palamartchouk, Xanthos Papanikolaou, Demitris Paradissis, Barry Parsons, David M. Pyle, Costas Raptakis, and Vangelis Zacharis. (2012) "Evolution of Santorini Volcano dominated by episodic and rapid fluxes of melt from depth." Nature Geoscience, 5(10):749{754, 2012. ISSN 1752-0894. doi: 10.1038/ngeo1562