Deformation Behavior Of Persistently Restless Telica Volcano, Nicaragua, during unrest in 2015

Open Access
Author:
Bussard, Rebecca
Area of Honors:
Earth Sciences
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Dr. Christelle Wauthier, Thesis Supervisor
  • Dr. Eliza Marone, Honors Advisor
Keywords:
  • Telica
  • Geodesy
  • InSAR
  • COSMOSkyMed
  • Central American Volcanic Arc
Abstract:
Persistently restless volcanoes experience frequent eruptions with Volcanic Explosivity Index of 2 or lower. Telica Volcano, located in Western Nicaragua, experienced major unrest beginning in May 2015 that lasted throughout the year, and that consisted of hundreds of several ash and gas explosions. Geodetic GPS measurements show ground deformation of approximately 1-2 cm occurring at Telica during these eruptions. An analysis of Interferometric Synthetic Aperture Radar (InSAR) Sentinel 1 images during this eruptive period confirm such deformation signals, but due to the relatively low spatial (~15 m) and temporal resolutions of the Sentinel-1 data, and the high level of noise they contained, deformation patterns are difficult to discern and interpret. For a clearer view of the deformation behavior at Telica during this unrest, we analyze a dataset consisting of 63 images from the COSMO-SkyMED satellite, characterized by a spatial resolution of ~1 m and a much higher temporal resolution than Sentinel 1. A multi-temporal analysis of this SAR dataset spanning December 2014 to December 2015 reveals a possible pattern of deflation before Telica volcano’s two major periods of activity in 2015.