New insights into the magma dynamics under Kilauea's East Rift Zone from May 2018 intrusion observed with time series InSAR
Abstract
Kilauea volcano, on the Big island Hawaii, is one of the most active volcanoes in the world marked by its continuous eruptive activity and flank motion. Though much of the magmatic activity occurs through the summit, intrusions into Kilauea's east rift zone has consistently been a topic of interest to determine how magma transfer, flank motion and rift zone opening is accommodated underneath the volcano. The last two intrusions in June 2007 and March 2011 were marked by significant seismic activity and surface deformation. The recent intrusion in May 2018, though similar in many ways to the previous intrusions in 2007 & 2011, has propagated significantly distal from the summit to reach the eastern edges of the island with magmatic activity still ongoing. In this study, we used more than 250 SAR images from Cosmo SkyMed and Sentinel series' to compute time series surface deformation on the edifice between last intrusion in 2011 through the recent intrusion. We observed steady inflation ( 40 cm) and rapid deflation of summit caldera before and after the intrusion indicating potential source of intrusion, yet strong displacement along rift zone and significant seismicity along the rift show possibility of existing magma sources in rift zone. Geodetic inversion of the surface deformation and combining them with seismicity provide useful insights into the magma dynamics and connecting systems underneath the volcano. We further study the intrusion event in connection to the M6.9 decollement earthquake which occurred a day after the intrusion (05/04/2018) and its role in facilitating rift opening and dike propagation. The earthquake is similar to the 1975 Kalapana earthquake which changed the stress course in the Kilauea rift zone significantly and facilitated frequent intrusions in the aftermath [Dieterich, 1988]. Using a finite element model considering the topography and gravity effects, we study the stress change caused by this M6.9 earthquake along the rift zone and explore the potential for future intrusive eruptions.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.V31H0229V
- Keywords:
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- 1207 Transient deformation;
- GEODESY AND GRAVITYDE: 9305 Africa;
- GEOGRAPHIC LOCATIONDE: 9604 Cenozoic;
- INFORMATION RELATED TO GEOLOGIC TIMEDE: 8178 Tectonics and magmatism;
- TECTONOPHYSICSDE: 8185 Volcanic arcs;
- TECTONOPHYSICSDE: 8415 Intra-plate processes;
- VOLCANOLOGYDE: 8488 Volcanic hazards and risks;
- VOLCANOLOGYDE: 8499 General or miscellaneous;
- VOLCANOLOGY