Spatio-temporal Evolution of the Magma Plumbing System at Masaya Caldera
Abstract
Volcanic unrest in calderas can be exhibited through a variety of different mechanisms, such changes in seismicity, ground deformation, thermal radiance, and/or gas emissions. However, not all caldera unrest results in explosive caldera-forming volcanic activity. Alternative activity may include a period of quiescence, or effusive activity in the form of lava flows or appearance of lava lakes. In late 2015, the Nicaraguan caldera Masaya exhibited signs of unrest with the formation of a lava lake at the summit. Studies spanning the 2015-2017 period using Interferometric Synthetic Aperture Radar (InSAR) and geodetic approaches observed a previously undetected magma body located 3 km to the north of the summit, with a radius of ~700 m and a depth-to-center of ~3 km. Gas geochemistry in-conjunction with InSAR time-series analysis and GPS data indicated that this region began inflating several weeks prior to the appearance of the lava lake. With this new insight into the magma plumbing system at Masaya, our current study aims to take advantage of the increase in available SAR datasets (such as Sentinel-1, ALOS-2, RADARSAT-2 and COSMO-SkyMed), to examine the long-term evolution of ground deformation within the caldera. Small BAseline Subset (SBAS) time-series analysis of the InSAR datasets will be used to help provide spatio-temporal information about the ground deformation during the 2015-present period of lava lake activity. Preliminary time-series results suggest continued ground deformation to the north of the summit as lava lake activity continues. Modelling of spatio-temporal ground deformation will then be performed to help inform us about changes in the volume and geometry of the magma body north of the summit. By linking these insights with available gas geochemistry, seismicity, lava lake levels and GPS observations, we will be able to improve our understanding of volcanic signals of unrest at Masaya and help provide better forecasting tools for future activity.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMV004.0019S
- Keywords:
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- 3618 Magma chamber processes;
- MINERALOGY AND PETROLOGY;
- 3640 Igneous petrology;
- MINERALOGY AND PETROLOGY;
- 8410 Geochemical modeling;
- VOLCANOLOGY;
- 8439 Physics and chemistry of magma bodies;
- VOLCANOLOGY