GNGTS 2017 - 36° Convegno Nazionale

GNGTS 2017 S essione 1.3 205 with a volume change of approximately 1.5×10 6 m 3 . This solution is consistent with the source, located midway between Nevado del Ruiz and Nevado de Santa Isabel volcanoes inferred by InSAR (Lundgren et al. , 2015). Analysis of tilt recorded between 2007 and 2012 suggested the accumulation of magma in the shallower reservoir that is feeding the gas release and ash emissions (Ordoñez et al. , 2014). Conclusions. Nevado del Ruiz is one of the most active volcanoes of the North Volcanic Complex of Colombia and the GPS data shows that the volcano has had a continuous deformation since 2010. The main activity includes an increase in seismicity, continuous gas (SO 2 ) release, frequent ash emissions, surface deformation and two moderate explosive eruptions (VEI = 2) in May and June 2012. The present volcanic unrest is controlled by two sources: • � ���� ����� ��������� ������� ������� ������ ��� ���� ��� ����� ������ ������� ������ a deep magma reservoir located between Nevado del Ruiz and Santa Isabel volcano (depth ~ 15 km, volume change ~ 10 6 m 3 ), inferred from the inversion of InSAR (Lundgren et al. , 2015) and GPS displacements (Fig. 3); analysis of GPS time series suggest that a batch of magma from this source may have moved from a depth of 15 km to a depth of 7 km between 2012 and 2015; • � ������� ���������� �������� ���� ��� ��������� �� ���� ����� ���� �� ������� ��� ��� ������� a shallow reservoir, inferred from the inversion of tilt data, that is feeding the gas release and ash emissions (Ordoñez et al. , 2014). References Battaglia M., Cervelli P., Murray J.R.; 2013: dMODELS: A MATLAB software package for modeling crustal deformation near active faults and volcanic centers . Journal of Volcanology and Geothhermal Research, 254 (2013), 1-4. Dzurisin D.; 2003: A comprehensive approach to monitoring volcano deformation as a window on the eruption cycle . Review of Geophysics 41 (1), 1–29. Herring T.A, King R.W., Floyd M.A. and McClusky S.C.; 2015: Introduction to GAMIT/GLOBK. Release 10.6 . Massachusetts Institute of Technology, Cambridge. Lundgren P., Samsonov S.V., López Velez C.M. and Ordoñez M.I; 2015: Deep source model for Nevado del Ruiz Volcano, Colombia, constrained by interferometric synthetic aperture radar observations . Geophys. Res. Lett., 42, 4816-4823, doi:10.1002/2015GL063858. McTigue D.F.; 1987: Elastic stress and deformation near a finite spherical magma body: resolution of the point source paradox . Journal of Geophysical Research 92, 12931–12940. Ordoñez M.I, López C.M. and Battaglia M.; 2014: Geodetic monitoring of 2012 eruptive activity at Nevado del Ruiz. Abstract presented at Cities on Volcanoes 8, Yogyakarta, Indonesia, 9-13 September 2014. Ordoñez M.I., López C.M., Alpala J., Narváez L., Arcos D. and Battaglia M.; 2015: Keeping watch over Colombia’s slumbering volcanoes . Eos, 96, doi:10.1029/2015EO025079. Published on February 27, 2015. Insights into the subsurface structure of Mt. Vetore pyroclastic cone (Etna) using ambient vibrations technique F. Panzera 1 , S. D’Amico 2 , A.W. Altemrawy 3 , T.A. Mansoob 3 , S. Gresta 1 , S. Imposa 1 , G. Lombardo 1 1 Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università degli Studi di Catania, Italy 2 Geosciences Department, University Msida, Malta 3 National Center for Earthquakes and Volcanoes, Saudi Geological Survey, Jeddah, Saudi Arabia Mt. Etna is located on the easter coast of the island of Sicily (Italy) and with a height of about 3350 m a.s.l. is the highest volcano in Europe. Several parasitic pyroclastic cones affect its flanks, concentrated along three main rifts converging at the summit (Rasà et al. , 1992). The rift of the northern flank matches with a narrow deformed zone trending NE, known as the NE Rift. The southern flank rift is coincident with a NNW-SSE zone of normal right-lateral faults mainly dipping eastward. The western flank rift is characterized by a ENE-WSW striking strike-slip faults system (Fig. 1).