3d multi source model of elastic volcanic ground deformation abstract developments in interferometric synthetic aperture radar insar and gnss global navigation satellite system during the past decades have promoted significant advances in geosciences providing high resolution ground deformation data with dense spatio temporal coverage this large dataset can be exploited to produce accurate assessments of the primary processes occurring in geologically active areas we present a new original methodology to carry out a multi source inversion of ground deformation data to better understand the subsurface causative processes a nonlinear approach permits the determination of location size and three dimensional configuration without any a priori assumption as to the number nature or shape of the potential sources the proposed method identifies a combination of pressure bodies and different types of dislocation sources dip slip strike slip and tensile that represent magmatic sources and other processes such as earthquakes landslides or groundwater induced subsidence through the aggregation of elemental cells this approach has the following features 1 simultaneous inversion of the deformation components and or line of sight los data 2 simultaneous determination of diverse structures such as pressure bodies or dislocation sources representing local and regional effects 3 a fully 3d context and 4 no initial hypothesis about the number geometry or types of the causative sources is necessary this methodology is applied to mt etna southern italy we analyze the ground deformation field derived from a large insar dataset acquired during the january 2009 june 2013 time period the application of the inversion approach models several interesting buried structures as well as processes related to the volcano magmatic plumbing system local subsidence within the valle del bove and seaward motion of eastern flank of the volcano

results for aseismic creep on the hayward fault using polarization persistent scatterer insar abstract we present new results for shallow aseismic creep on the hayward fault in california using a new dinsar technique this method not only provides for the first time the ability to map the displacement field on both sides of the fault it does so over a much shorter time period than earlier results the results provide a good match in the near field to both the regional continuous gps velocities and data from an alinement network that measures long term creep along the fault the average slip rate for the northern segment of the hayward fault is 4 4 mm yr between 2008 and 2011 slightly less than that estimated for longer time periods suggesting that the slip rate may not be constant if the slip rate along the fault is variable on the decadal or longer scale current estimates of its earthquake potential and the associated hazard associated with the slip rate deficit may need to be revised from previous estimates we demonstrate the potential impact of this method to better define the spatial and temporal complexity of aseismic slip and estimate the accumulated elastic strain along one of the most significant sources of seismic hazard in the san francisco bay area

gravity changes and deformation due to a magmatic intrusion in a two layered crustal model we develop and extend theoretical and computational methods for the calculation of the deformation gravity and potential change due to a point source of magma injection into a multilayered elastic gravitational earth model in our calculations which are based upon the method outlined by rundle two distinct layers overlying a half space may be incorporated the source can be located in either of the layers or the half space the method is quite general and can be readily adapted to calculations in which stresses in either the layers or the half space relax by viscoelastic flow the results obtained indicate that the use of homogeneous half space to represent the earth may in some cases be too simple a model and that variations in elastic moduli have a more significant effect than variation in reference density on both the surface displacements and gravity changes as an example we calculate the displacement and gravity changes due to a subsurface mass injection in a crust mantle model appropriate to the volcanic island of lanzarote which is presently the subject of numerous geophysical experiments both historical and recent data indicate that lanzarote may be subject to some risk of volcanic eruption in the future thus our calculations may be useful in interpreting observations of preemption phenomena the results are discussed in terms of prediction versus measurement capabilities

origin ore forming fluid evolution and timing of the logrosan sn w ore deposits central iberian zone spain the logrosan sn w ore deposits in the metallogenic sn w province of the european variscan belt consist of endo and exogranitic greisen type and quartz cassiterite veins associated with a s type granite mineral characterization fluid inclusion study isotope geochemistry and ar ar geochronology have been combined in order to reconstruct the conditions for sn w mineralization the endo and exogranitic mineralization must have been developed in a relatively long lived system 308 303 ma during or soon after the emplacement of the logrosan related granite at ca 308 ma the mineralizing fluids are characterized by complex aqueous and volatile h2o n2 co2 ch4 nacl fluid inclusions microthermometry and raman analyses indicate that fluid composition evolved from n2 ch4 to n2 rich followed by co2 rich fluids with varying amounts of h2o the presence of n2 and ch4 suggests the interaction with fluids derived from the nearby metasedimentary host rocks a model of host rock interaction assimilation and mixing of metamorphic and magmatic fluids resulting in change of the redox conditions is proposed for tin deposition later sulfide minerals were precipitated as a result of pressure and temperature release

multidimensional time series analysis of ground deformation from multiple insar data sets applied to virunga volcanic province summary a novel multidimensional small baseline subset msbas methodology is presented for integration of multiple interferometric synthetic aperture radar insar data sets for computation of 2 or 3 d time series of deformation the proposed approach allows the combination of all possible air borne and space borne sar data acquired with different acquisition parameters temporal and spatial sampling and resolution wave band and polarization the produced time series have improved temporal resolution and can be enhanced by applying either regularization or temporal filtering to remove high frequency noise we apply this methodology to map 2003 2010 ground deformation of the virunga volcanic province vvp north kivu democratic republic of congo the horizontal and vertical time series of ground displacement clearly identify lava compaction areas long term deformation of mt nyamuragira and 2004 2006 and 2010 pre and coeruptive deformation providing that enough sar data is available the method opens new opportunities for detecting ground motion in the vvp and elsewhere

post eruptive deformation associated with the 1986 87 and 1989 lava flows of etna detected by radar interferometry we analysed 92 interferograms produced using ers1 sar images taken on etna between may 1992 and october 1993 nineteen show a local subsidence in the eastern flank of the volcano correlated with the location of the 30 october 1986 1 march 1987 and 27 september 9 october 1989 lava flows using fringe unwrapping and data gridding techniques and assuming that over the sampled time window deformation was a linear function of time we derive a map of along range rate of motion the correlation between the deformation field and the area covered by recent lavas suggests that compaction of the lava flows continues several years after the eruptions the area of maximum subsidence 47 mm yr is localised at the narrowing of the 1989 flow between 1500 and 1700 m a s l we observe that subsidence extends outside the lava flows accounting for at least 12 mm yr assuming a relaxation process of the substrate in response to loading produced by recent lavas a simple 1d maxwell visco elastic model predicts a maximum subsidence rate of 25 mm yr and a relaxation time of about 3 5 years the relaxation time agrees with those derived from post eruptive displacements observed by levelling on etna and piton de la fournaise after several eruptions we conclude that at the time of our measurements 25 to 50 of the deformation was related to relaxation of the substrate and the other part due to compaction of the lava flows

the effects of topography on magma chamber deformation models application to mt etna and radar interferometry we have used a three dimensional elastic finite element model to examine the effects of topography on the surface deformation predicted by models of magma chamber deflation we used the topography of mt etna to control the geometry of our model and compared the finite element results to those predicted by an analytical solution for a pressurized sphere in an elastic half space topography has a significant effect on the predicted surface deformation for both displacement profiles and synthetic interferograms not only are the predicted displacement magnitudes significantly different but also the map view patterns of displacement it is possible to match the predicted displacement magnitudes fairly well by adjusting the elevation of a reference surface however the horizontal pattern of deformation is still significantly different thus inversions based on constant elevation reference surfaces may not properly estimate the horizontal position of a magma chamber we have investigated an approach where the elevation of the reference surface varies for each computation point corresponding to topography for vertical displacements and tilts this method provides a good fit to the finite element results and thus may form the basis for an inversion scheme for radial displacements a constant reference elevation provides a better fit to the numerical results

the continuing story of etna s new southeast crater 2012 2014 evolution and volume calculations based on field surveys and aerophotogrammetry abstract during the years 2013 2014 the new southeast crater nsec at the summit of mount etna produced frequent episodes of lava fountaining paroxysms and its cone continued to grow at unprecedented rates many of the episodes were of rather brief duration and violently explosive producing mostly pyroclastic material and minor volumes of lava other episodes especially those since mid december 2013 were characterized by violent strombolian activity without producing sustained lava fountains and significant amounts of tephra but emitting more voluminous lava flows one episode of intense strombolian and effusive activity that was possibly fed from the nsec conduit occurred from vents located approximately 1 km north of the crater on the east flank of the northeast crater in july august 2014 the evolution of the nsec cone between 2012 and 2014 was documented by repeated gps surveys carried out both from a distance and on the cone itself by the acquisition of comparison photographs and by two aerophotogrammetric surveys from these surveys the highest point of the nsec results to have grown from 190 m may 2012 to 215 m october 2014 above the pre cone surface reaching an elevation of 3290 m and its volume more than doubled to 50 0 6 5 10 6 m 3 representing the 40 of the total bulk volume of the volcanic products including pyroclastic fallout erupted in 2011 2014 which is 147 2 10 6 m 3 101 3 10 6 m 3 dense rock equivalent the whole of the 2011 2014 nsec activity marks an unusually high frequency of rather explosive tephra rich eruptive episodes compared to etna s activity in past decades and centuries although the average magma production rate in this interval is close to the supposed long term output rate of the volcano the latest eruptive episodes show a tendency of the nsec coalescing with the old southeast crater cone which therefore represents a miniature example of a growing compound volcano at the summit of etna

volcanic eruption prediction magma chamber physics from gravity and deformation measurements one of the greatest remaining problems in modern volcanology is the process by which volcanic eruptions are triggered it is generally accepted that eruptions are preceded by magma intrusion sigurdsson and sparks 1978 the degree of interaction between previously ponded magma in a chamber and newly intruded magma determines the nature and rate of eruption and also the chemistry of erupted lavas and shallow dykes here we investigate the physics of this interaction volcano monitoring at its most effective is a synergy between basic science and risk assessment while hazard mitigation depends on reliable interpretation of eruption precursors the simple and much used mogi model relates ground deformation h to changes in magma chamber volume gravity changes g combined with ground deformation provide information on magma chamber mass changes our new models predict how the g h gradient will evolve as a volcano develops from a state of dormancy through unrest into a state of explosive activity thus by simultaneous measurement of deformation and gravity at a few key stations magma chamber processes can be identified prior to the onset of conventional eruption precursors

deformation gravity and potential changes due to volcanic loading of the crust a method for calculating deformation gravity and potential changes induced by volcanic loads imposed within and on the earth s crust is presented the method involves application of techniques developed for earthquake loading problems in elastic gravitational earth models by considering the elastic gravitational equilibrium of the layered system the gravitational and displacement response due to intruding masses and to pressurized magma chambers can be computed for applications involving seamount loading variations in the height of sea level can be calculated by requiring that seawater lie along an equipotential in continental loading problems the change in potential can be used to calculate the orthometric height cahnge as distinct from the geometric height change for some plausible loading geometries the difference between these two qunatities can be significant results for various loads and earth structures are shown and discussed in particular a magmatic mass intruding into an elastic gravitational lithosphere overlying a compressible gravitating asthenosphere produces distinct gravity anomalies which depend on the depth of intrusion applications of this result can be made to problems of isostatic compensation the intrusion of a magmatic mass together with the associated pressurization of the magma chamber produces distinctive surface gravity and deformation in the near field gravity gradients more defined as surface gravity divided by uplift vary with distance from the source moreover orthometric elevations can be significantly 25 less than geometric elevations these results have clear application to data from events such as the posteruption deflation of kilauea volcano less

inflation or deflation new results for mayon volcano applying elastic gravitational modeling volcanic activity produces deformation and gravity changes that many times can be used as precursors of future eruptions applying geodetic techniques to monitoring activity involves interpretation using deformation models usually the observed changes of the deformation and gravity fields are interpreted seperately not in a joint inversion it can be difficult if not impossible to interpret the data coherently or correctly in terms of the characteristics of the intrusion or the deflation derived from the gravity changes with purely elastic models as in the case of mayon volcano phillipines we show that elastic gravitational models can be used to interpret these cases simultaneously leading to a result that is more plausible on the basis of the available information thus we may need to change the philosophy normally used to interpret geodetic observations interpretation as proposed in this work can significantly improve the possibility of predicting future eruptions

detection of displacements on tenerife island canaries using radar interferometry tenerife is one of the most well monitored islands of the canaries but the surveillance generally is centred on las canadas caldera where the teide volcano is located in the last 180 000 yr the eruptions on tenerife island have never occurred in the same volcanic structure except for the teide and pico viejo central volcanic system so that a complete monitoring network would have to cover the whole island as a result synthetic aperture radar interferometry insar is being used on tenerife because this space technique can provide a displacement map of the surface of the earth with centimetre precision this paper presents the results obtained on tenerife island using 18 sar images acquired by the ers 1 and ers 2 satellites during the period 1992 2000 two important results have been obtained no deformation on las canadas caldera coinciding with results obtained using terrestrial techniques and two subsidence episodes outside monitoring areas in the nw of the island in the region of the last historic eruptions these results show that insar is a useful technique for monitoring the entire island thus allowing us to discover deformations in areas that are not routinely or easily monitored this technique has been used in combination with global positioning system gps observation of a global network on the island to define a new geodetic monitoring system the possible causes of the deformations observed have been studied in an endeavour to discern if they might be of natural origin in particular linked to a reactivation of prior volcanic activity examination of the geophysical observations on the island human activities underway and the results of the modelling seem to indicate that at least part of the deformations may be caused by changes in the groundwater level and therefore are not linked to a volcanic reactivation this result is important because it implies that if geodetic volcano monitoring is to be performed on the island the system used must be capable of discerning between various possible origins of the deformation by analysing their patterns and ancillary information from other sources in this regard insar is a basic tool on account of its unpaired wide area coverage and spatial density

gps velocity and strain fields in sicily and southern calabria italy updated geodetic constraints on tectonic block interaction in the central mediterranean 1 we present an improved rendition of the geodetic velocity and strain fields in sicily and southern calabria obtained through the analysis of 18 years of gps observations from continuous and survey station networks the dense spatial coverage of geodetic data provides precise quantitative estimates of previously established first order active kinematic features including i a narrow east west elongated belt of contraction 1 1 5 mm yr extending offshore northern sicily from ustica to stromboli across the aeolian islands ii a narrow east west trending contractional belt located along the northern rim of the hyblean plateau in southern sicily with shortening at up to 4 4 mm yr iii right motion 3 6 mm yr on the aeolian tindari letojanni fault atlf system a main shear zone extending from the aeolian islands to the ionian coast of sicily with significant transpression and transtension partitioned between discrete sectors of the fault iv transtension 1 mm yr across the sicily channel between sicily and north africa we use geodetic observations coupled to geological constraints to better elucidate the interplay of crustal blocks revealed in the investigated area in particular we focus on the atlf which forms the primary boundary between the sicilian and calabrian blocks the atlf juxtaposes north south contraction between sicily and the tyrrhenian block with northwest southeast extension in northeastern sicily and calabria contraction between sicily and tyrrhenian blocks probably arises from the main europe nubia convergence although sicily has a component of lateral motion away from nubia we found that convergence is not restricted to the northern offshore as commonly believed but is widely accommodated between the frontal belt and the northern rim of the hyblean foreland in southern sicily geodetic data also indicate that active right shear on the atlf occurs to the southeast of the mapped fault array in northern sicily suggesting the fault cuts through till the ionian coast of the island the small geodetic divergence between the hyblean and apulian blocks rimming on both sides the calabria block and subjacent ionian slab coupled with marine geophysical evidences in the ionian sea lends credit to the proposed deep root of the atlf and to a fragmentation of the ionian domain

spatiotemporal analysis and interpretation of 1993 2013 ground deformation at campi flegrei italy observed by advanced dinsar campi flegrei is one of the most hazardous volcanic areas in the world because of its close proximity to the city of naples here we apply the multidimensional small baseline subset msbas differential interferometric synthetic aperture radar dinsar technique to obtain vertical and horizontal components of ground deformation for campi flegrei at high spatial and temporal resolutions that span for the first time 20 years the area underwent continuous subsidence from 1993 through 1999 moderate uplift began in 2010 and substantially increased through 2012 reaching approximately 13 cm by 2013 we model the observed deformation to determine source parameters for subsidence and uplift epochs both the inflation and deflation mechanisms involve large extended sources in a layered hydrothermal system whose location is controlled by the caldera structure and stratigraphy the temporal resolution of msbas approaches that of gps daily time series with superior precision and spatial resolution making it an excellent alternative for volcano monitoring

flank instability structure of mt etna inferred by a magnetotelluric survey this paper presents a magnetotelluric mt survey of the unstable eastern flank of mt etna we take thirty soundings along two profiles oriented in the n s and nw se directions and from these data recover two 2d resistivity models of the subsurface both models reveal three major layers in a resistive conductive resistive sequence the deepest extending to 14 km bsl the shallow layer corresponds to the volcanic cover and the intermediate conductive layer corresponds to underlying sediments segmented by faults these two electrical units are cut by e w striking faults the third layer basement is interpreted as mainly pertinent to the apennine maghrebian chain associated with sw ne striking regional faults the detailed shapes of the resistivity profiles clearly show that the ne rift is shallow rooted 0 1 km bsl thus presumably fed by lateral dikes from the central volcano conduit the nw se profile suggests by a series of listric faults reaching up to 3 km bsl then becoming almost horizontal toward the se the resistive basement dramatically dips from 3 km to 10 km bsl in correspondence with the timpe fault system several high conductivity zones close to the main faults suggest the presence of hydrothermal activity and fluid circulation that could enhance flank instability our results provide new findings about the geometry of the unstable etna flank and its relation to faults and subsurface structures

on precisely modelling surface deformation due to interacting magma chambers and dykes combined data sets of insar and gps allow us to observe surface deformation in volcanic settings however at the vast majority of volcanoes a detailed 3 d structure that could guide the modelling of deformation sources is not available due to the lack of tomography studies for example therefore volcano ground deformation due to magma movement in the subsurface is commonly modelled using simple point mogi or dislocation okada sources embedded in a homogeneous isotropic and elastic half space when data sets are too complex to be explained by a single deformation source the magmatic system is often represented by a combination of these sources and their displacements fields are simply summed by doing so the assumption of homogeneity in the half space is violated and the resulting interaction between sources is neglected we have quantified the errors of such a simplification and investigated the limits in which the combination of analytical sources is justified we have calculated the vertical and horizontal displacements for analytical models with adjacent deformation sources and have tested them against the solutions of corresponding 3 d finite element models which account for the interaction between sources we have tested various double source configurations with either two spherical sources representing magma chambers or a magma chamber and an adjacent dyke modelled by a rectangular tensile dislocation or pressurized crack for a tensile okada source representing an opening dyke aligned or superposed to a mogi source magma chamber we find the discrepancies with the numerical models to be insignificant 5 per cent independently of the source separation however if amogi source is placed side by side to an okada source in the strike perpendicular direction we find the discrepancies to become significant for a source separation less than four times the radius of the magma chamber for horizontally or vertically aligned pressurized sources the discrepancies are up to 20 per cent which translates into surprisingly large errors when inverting deformation data for source parameters such as depth and volume change beyond 8 radii however we demonstrate that the summation of analytical sources represents adjacent magma chambers correctly

flank cones at mount etna volcano do they have a power law distribution mount etna is currently characterised by intense effusive and explosive activity of its summit vents whereas 319 non active holocene flank cones are spread across its flanks at altitudes of between 2990 and 475 m in volcanic areas the relationships between fracture occurrence and cone growth location are well established with this in mind the spatial distribution of the mount etna flank cones was analysed in order to make some inferences about the fracture systems that feed the cones the positions of the flank cones were acquired by the use of a digital elevation model of the volcano with a geometric resolution of 10 10 m spatial distribution of the cones was analysed through counting box and sand box methods checking for fractal or multifractal behaviours the four data sets analysed consist of the whole number of parasitic cones 319 and cones located on the ne 50 south 143 and west 61 rifts respectively the cones have a non trivial power law distribution the sand box method gave the best results with a fractal exponent df for all cones of 1 41 0 02 over the length range 0 2 10 km the same analysis was performed on the other data sets south rift 1 42 0 02 west rift 1 39 0 02 and ne rift 1 43 0 02 the cones do not have a multifractal distribution as suggested also by the strong similarity between fractal exponents of the different data sets data suggest a strong control over flank cone distribution by fracture length and density these two characteristics are in turn expressions of highly connected fractures activated as magma feeders by the volcano s present stress field we interpret the rifts as inherited structures that represent preferential sites of fracture connectivity

pressurization and depressurization phases inside the plumbing system of mount etna volcano evidence from a multiparametric approach during 2013 mount etna volcano experienced intense eruptive activity at the summit craters foremost at the new southeast crater and to a minor degree at the voragine and bocca nuova bn which took place in two cycles february april and september december in this work we mainly focus on the period between these cycles applying a multiparametric approach the period from the end of april to 5 september showed a gradual increase in the amplitude of long period lp events and volcanic tremor a slight inflation testified by both tilt and gps data and a co2 flux increase such variations were interpreted as due to a gradual pressurization of the plumbing system from the shallowest part where lp and volcanic tremor are located down to about 3 9 km below sea level pressure source depths obtained by both geodetic and co2 data on 5 september at the same time as a large explosion at bn we observed an instantaneous variation of the aforementioned signals decrease in amplitude of lp events and volcanic tremor slight deflation and co2 flux decrease and the activation of a new infrasonic source located at bn in the light of it the bn explosion probably caused the instantaneous end of the pressurization and the opening of a new vent at bn that has become a new steady source of infrasonic events this apparently slight change in the plumbing system also led to the gradual resumption of activity at the new southeast crater culminating with the second lava fountain cycle of 2013

gravimetric determination of an intrusive complex under the island of faial azores some methodological improvements summary we present some improvements of a gravity inversion method to determine the geometry of the anomalous bodies for priori density contrasts the 3 d method is based on an exploratory process applied not for the global model but for the steps of a growth approach the positive and or negative anomalous structure is described by successive aggregation of cells while its corresponding gravity field remains nearly proportional to the observed one moreover a simple e g linear regional trend can be simultaneously adjusted the corresponding program is applied to new gravity data on the volcanic island of faial azores archipelago the inversion approach shows a subsurface anomalous structure for the island the main feature being an elongated high density body the body is interpreted as a compact sheeted dyke swarm emplaced along faial pico fracture zone a leaky transform structure that forms the current boundary between eurasian and african plates in the azores area the new results in this paper are 1 a bouguer gravity anomaly map 2 several improvements in the inversion process robust process optimal balance fitness model magnitude 3 a new gravimetric method for estimating the mean terrain density 4 a 3 d model for subsurface mass anomalies in faial and 5 some interpretative conclusions about a main intrusive complex detected under the island as a wall like structure extending from a depth of 0 5 to 6 km b s l with a n100 e trend

composite fabrics in mid crustal gneisses observations from the oygarden complex west norway caledonides subhorizontal caledonian shear zones that transform migmatitic gneisses into layered gneissic tectonites in the western part of the oygarden complex show a number of composite fabrics the associated structures consist of two sets of related planar surfaces showing a consistent top to the west sense of shear the development of these structures depends mainly on the nature and variation of finite strain rheology strain heterogeneities and extent of metamorphic mineral growth and recrystallization in the shear zones the structures have one set of surfaces represented by slip surfaces or narrow high strain zones oblique to this is a complementary set of surfaces representing either a plane of mineral flattening or aligned metamorphic minerals in s c structures or rotated gneissic foliation in contractional and extensional composite structures rotation by folding and subsequent slip along limbs or axial planar cleavage results in contractional composite structures while rotation by downward cutting extensional type slip surfaces form extensional composite structures contractional and extensional composite structures involve slip transfer across the mylonitic layering commonly between terminating weak layers within strongly anisotropic layered tectonites combinations of the different types of composite structures are common but the method of shear sense identification is always the same

radar interferogram filtering for geophysical applications the use of sar interferometry is often impeded by decorrelation from thermal noise temporal change and baseline geometry power spectra of interferograms are typically the sum of a narrow band component combined with broad band noise we describe a new adaptive filtering algorithm that dramatically lowers phase noise improving both measurement accuracy and phase unwrapping while demonstrating graceful degradation in regions of pure noise the performance of the filter is demonstrated with sar data from the ers satellites over the jakobshavns glacier of greenland

insights into magma and fluid transfer at mount etna by a multiparametric approach a model of the events leading to the 2011 eruptive cycle 1 since the second half of the 1990s the eruptive activity of mount etna has provided evidence that both explosive and effusive eruptions display periodic variations in discharge and eruption style in this work a multiparametric approach consisting of comparing volcanological geophysical and geochemical data was applied to explore the volcano s dynamics during 2009 2011 in particular temporal and or spatial variations of seismicity volcano tectonic earthquakes volcanic tremor and long period and very long period events ground deformation gps and tiltmeter data and geochemistry so2 flux co2 flux co2 so2 ratio were studied to understand the volcanic activity as well as to investigate magma movement in both deep and shallow portions of the plumbing system feeding the 2011 eruptive period after the volcano deflation accompanying the onset of the 2008 2009 eruption a new recharging phase began in august 2008 this new volcanic cycle evolved from an initial recharge phase of the intermediate shallower plumbing system and inflation followed by i accelerated displacement in the volcano s eastern flank since april 2009 and ii renewal of summit volcanic activity during the second half of 2010 culminating in 2011 in a cyclic eruptive behavior with 18 lava fountains from new southeast crater nsec furthermore supported by the geochemical data the inversion of ground deformation gps data and the locations of the tremor sources are used here to constrain both the area and the depth range of magma degassing allowing reconstructing the intermediate and shallow storage zones feeding the 2011 cyclic fountaining nsec activity