CONICET | Buscador de Institutos y Recursos Humanos

We have investigated the surface deformation of the eastern California area that includes Long Valley caldera and Mono Basin. We apply the SAR Interferometry (InSAR) algorithm referred to as Small BAseline Subset (SBAS) approach that allows us to generate mean deformation velocity maps and displacement time series for the investigated area. The presented analysis, based on SAR data acquired by the ERS-1/2 sensors during the 1992-2000 time interval, demonstrates the capability of the SBAS procedure to analyze deformation for an overall area spanning approximately 5,000 km2. We identify and analyze displacement patterns at different spatial scales. Two previously unreported localized deformation effects have been detected at Paoha Island, located within the Mono Lake, and in the McGee Creek area within the Sierra Nevada mountains, a zone to the south of the Long Valley caldera. In addition, a spatially extended uplift effect has been identified which strongly affects the Long Valley caldera but also extends beyond the caldera boundaries, particularly in northern direction. This uplift phenomenon has been analyzed in details; in particular, the InSAR results clearly show that the displacement phenomena affecting the Long Valley caldera have a maximum in correspondence of the resurgent dome and are characterized by the sequence of three different effects: a 1992-1997 uplift background, a 1997-1998 unrest phenomenon and a 1998-2000 subsidence phase. Moreover, the analysis of the retrieved displacement time series allowed us to map the extent of the zone with a temporal deformation behavior highly correlated with the detected three-phases deformation pattern: background upliftunrest-subsidence. We note that the mapped area clearly extends outside the northern part the caldera slopes. Finally, a comparison between the InSAR measurements and a set of geodetic data confirms the validity of the results achieved through the SBAS-InSAR analysis. We identify and analyze displacement patterns at different spatial scales. Two previously unreported localized deformation effects have been detected at Paoha Island, located within the Mono Lake, and in the McGee Creek area within the Sierra Nevada mountains, a zone to the south of the Long Valley caldera. In addition, a spatially extended uplift effect has been identified which strongly affects the Long Valley caldera but also extends beyond the caldera boundaries, particularly in northern direction. This uplift phenomenon has been analyzed in details; in particular, the InSAR results clearly show that the displacement phenomena affecting the Long Valley caldera have a maximum in correspondence of the resurgent dome and are characterized by the sequence of three different effects: a 1992-1997 uplift background, a 1997-1998 unrest phenomenon and a 1998-2000 subsidence phase. Moreover, the analysis of the retrieved displacement time series allowed us to map the extent of the zone with a temporal deformation behavior highly correlated with the detected three-phases deformation pattern: background upliftunrest-subsidence. We note that the mapped area clearly extends outside the northern part the caldera slopes. Finally, a comparison between the InSAR measurements and a set of geodetic data confirms the validity of the results achieved through the SBAS-InSAR analysis. 2. We identify and analyze displacement patterns at different spatial scales. Two previously unreported localized deformation effects have been detected at Paoha Island, located within the Mono Lake, and in the McGee Creek area within the Sierra Nevada mountains, a zone to the south of the Long Valley caldera. In addition, a spatially extended uplift effect has been identified which strongly affects the Long Valley caldera but also extends beyond the caldera boundaries, particularly in northern direction. This uplift phenomenon has been analyzed in details; in particular, the InSAR results clearly show that the displacement phenomena affecting the Long Valley caldera have a maximum in correspondence of the resurgent dome and are characterized by the sequence of three different effects: a 1992-1997 uplift background, a 1997-1998 unrest phenomenon and a 1998-2000 subsidence phase. Moreover, the analysis of the retrieved displacement time series allowed us to map the extent of the zone with a temporal deformation behavior highly correlated with the detected three-phases deformation pattern: background upliftunrest-subsidence. We note that the mapped area clearly extends outside the northern part the caldera slopes. Finally, a comparison between the InSAR measurements and a set of geodetic data confirms the validity of the results achieved through the SBAS-InSAR analysis.

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