INSAR TIME SERIES ANALYSIS OF SURFACE DEFORMATION AT PACAYA, GUATEMALA

The Pacaya volcano complex, located 25 km south of Guatemala City, is intermittently active and presents several sources of surface deformation measurable via interferometric synthetic aperture radar (InSAR). Persistent scatterer and small baseline methods are applied to produce an InSAR time series using data acquired by the Radarsat-2 satellite covering Pacaya from mid 2014 into 2015. This approach is effective for detecting spatially and temporally complicated volcanic deformation and can mitigate atmospheric effects commonly encountered when applying InSAR in tropical areas such as Guatemala. InSAR measurements, combined with observations from high-resolution optical satellite imagery, are used to identify longer-term surface deformation at Pacaya. This information can be used to model processes causing observed deformation, the most significant of which occurs along the southern flank of the MacKenney cone. Knowing the edifice has collapsed in the past, most recently between 0.6-1.6 ka, it is imperative to fully understand the long-term flank deformation at Pacaya for hazard mitigation purposes.