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Universidad Nacional Autonoma de Mexico, Queretaro, Mexico
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- PublicationOpen AccessTectonic, volcanic and human activity: ground deformation signals detected by multitemporal InSAR techniques in the Colima Volcanic Complex rift (Mexico(2010-12-15)
; ; ; ; ; ; ; ; ; ; ;Brunori, Carlo Alberto; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Bignami, Christian; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Trasatti, Elisa; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Stramondo, Salvatore; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia ;Zucca, Francesco; Università di Pavia - Dip.Scienze della Terra (Pavia, ITALY) ;Groppelli, Gianluca; C.N.R. – Istituto per la Dinamica dei Processi Ambientali, Milano, Italy ;Norini, Gianluca; Università degli Studi di Milano-Bicocca (Milano, ITALY) - Universidad Nacional Autonoma de Mexico, Queretaro, Mexico ;Capra, Lucia; Universidad Nacional Autonoma de Mexico, Queretaro, Mexico ;Cabral-Cano, Enrique; Instituto de Geofìsica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria Del. Coyoacan ;Marquez-Azua, Bertha; Instituto de Geofìsica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria Del. Coyoacan; ; ; ; ; ; ; ; ; ; ; ;Ward, Joanna; American Geofisical Union (S.Francisco-CA USA)The evolution of volcanoes is strictly related with their substratum and the regional tectonics. The link among morphology, geology and structure of volcanic edifices and the geologicalstructural characteristics of the basement is important to understand hazardous phenomena as flank eruptions and lateral collapses of volcanoes. The Colima Rift is an active regional structure, N-S oriented and more than 100 km long and 10 wide. This rift is filled by a ~1 km-thick sequence of quaternary lacustrine sediments, alluvium, and colluvium, mostly underling the about 3000 m thick volcanic pile of the Colima Volcanic Complex (CVC). In addition to the regional structures curved faults, roughly E-W oriented, are observed on the CVC edifice due to the spreading of the volcano moving southward on the weak basement. So in the CVC edifice and surrounding area we can observe the interaction of regional structures and volcanic ones due to the gravitational loading of the volcanic edifice on the weak substratum of the graben. To measure displacements due to magma movement at depth and interaction of regional structures and volcanic ones, SAR interferometry has proven to be a reliable method; however, andesitic stratovolcanoes like the CVC indeed,remain difficult to survey using this technique. The main causes are their specific geometry (steep topography), which induces strong tropospheric artefacts, environmental conditions (e.g.,mainly vegetation, ash and/or snow cover), leading to a loss of coherency. In this work we try to detect deformations phenomena for the wide CVC using a robust multitemporal InSAR approach Differential Synthetic Aperture Radar Interferometry (DInSAR). We apply the Hooper (2008) DInSAR algorithm (StamPS/MTI) both to ENVISAT ASARr images acquired from 1993 to 2007 and to ALOS PALSAR (datasets from 2006 to 2010) in order to determine the deformation patterns in the CVC.350 819 - PublicationOpen AccessAnalysing stress field conditions of the Colima Volcanic Complex (Mexico) by integrating finite-element modelling (FEM) simulations and geological data(2020)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; In the last decades numerical methods have become very popular tools in volcanological studies, since capable of considering many relevant parameters in their calculations, such as the presence of multiple reservoirs, topography, and heterogeneous distribution of the host rock mechanical properties. Although the widespread availability of geodetic data is keep growing, the influence of geological data on the numerical simulations is still poorly considered. In this work a 2D Finite Element Modelling is provided by using the commercial Linear Static Analysis (LISA) software, in order to investigate the stress field conditions occurring around the Colima Volcanic Complex (CVC, Mexico) at increasing the details of geological and geophysical input data. By integrating the published geophysical, volcanological and petrological data, we provide a first-order domain of the CVC feeding system, considering either one or two magma chambers connected to the surface via dykes or isolated (not connected) in the elastic host rocks. We test the methodology by using a gravitational modelling with different geometrical configurations and constraints (i.e. magma chamber dimensions, depth, overpressure). Our results suggest that an appropriate set of geological data is of pivotal importance for improving the mesh generation procedures and the degree of accuracy of numerical outputs, aimed to more reliable physics-based representations of the natural systems.177 37 - PublicationOpen AccessProbabilistic volcanic hazard assessment at an active but under-monitored volcano: Ceboruco, MexicoA probabilistic volcanic hazard assessment (PVHA) for Ceboruco volcano (Mexico) is reported using PyBetVH, an e-tool based on the Bayesian Event Tree (BET) methodology. Like many volcanoes, Ceboruco is under-monitored. Despite several eruptions in the late Holocene and efforts by several university and government groups to create and sustain a monitoring network, this active volcano is monitored intermittently rather than continuously by dedicated groups. With no consistent monitoring data available, we look at the geology and the eruptive history to inform prior models used in the PVHA. We estimate the probability of a magmatic eruption within the next time window (1 year) of ~ 0.002. We show how the BET creates higher probabilities in the absence of monitoring data, which if available would better inform the prior distribution. That is, there is a cost in terms of higher probabilities and higher uncertainties for having not yet developed a sustained volcano monitoring network. Next, three scenarios are developed for magmatic eruptions: i) small magnitude (effusive/explosive), ii) medium magnitude (Vulcanian/sub-Plinian) and iii) large magnitude (Plinian). These scenarios are inferred from the Holocene history of the volcano, with their related hazardous phenomena: ballistics, tephra fallout, pyroclastic density currents, lahars and lava flows. We present absolute probability maps (unconditional in terms of eruption size and vent location) for a magmatic eruption at Ceboruco volcano. With PyBetVH we estimate and visualize the uncertainties associated with each probability map. Our intent is that probability maps and uncertainties will be useful to local authorities who need to understand the hazard when considering the development of long-term urban and land-use planning and short-term crisis management strategies, and to the scientific community in their efforts to sustain monitoring of this active volcano.
51 9 - PublicationRestrictedShallow-water models for volcanic granular flows: A review of strengths and weaknesses of TITAN2D and FLO2D numerical codesThe behaviour of dry and wet volcanic granular flows is one of the main research topics in present day geophysics and volcanology. It involves various disciplines (e.g. sedimentology, geophysics, fluid dynamics) and investigation techniques (e.g. field studies, laboratory experiments, computational fluid dynamics). The vast interest is justified by the complex nature of these flows and their very dangerous nature that threaten millions of people around the world. In the last decade, computational fluid dynamics has become one of the main instruments used to reproduce past events of volcanic granular flows or to predict their behaviour and potential hazard. In this study, we tested two of the most used codes for simulating volcanic granular flows, TITAN2D and FLO2D, against well studied natural cases (the 1998 wet granular flows in the Sarno area and the 2005 block and ash flows at Colima volcano) and large-scale experiments on granular flows. Comparison between simulated parameters and real ones were carried out in order to evaluate strengths and weaknesses of the two numerical codes. TITAN2D results showed how the basal friction angle is fundamental to control numerical simulations and its dependence on the topographic complexities, DEM resolution and slope-angle ratio. Simulation of large scale experiments offered a good relationship between slope angle ratio at break in slope and basal friction angle, which is useful for application to small drainage basins with not complex channel morphology. FLO2D suffers the lack of rheometric parameters for volcaniclastic material, but is less sensitive of DEM resolution with respect to TITAN2D.
40 22 - PublicationRestrictedMorphological analysis of Nevado de Toluca volcano (Mexico): new insights into the structure and evolution of an andesitic to dacitic stratovolcano(2004-04-23)
; ; ; ; ;Norini, G.; Dipartimento di Scienze della Terra—A. Desio, Universita` degli Studi di Milano, via Mangiagalli 34, 20133 Milano, Italy ;Groppelli, G.; CNR, Istituto per la Dinamica dei Processi Ambientali, via Mangiagalli 34, 20133 Milano, Italy ;Capra, L.; Instituto de Geografı´a, Universidad Nacional Auto´noma de Me´xico, C.U., Coyoaca´n, 04510 Me´xico D.F., Mexico ;De Beni, E.; Dipartimento di Scienze Geologiche, Universita` degli Studi di Catania, Corso Italia 55, 95129 Catania, Italy; ; ; We present a morphological analysis of Nevado de Toluca volcano located 80 km WSW of Mexico City based on digital elevation model study, where slope and aspect maps have been generated and analysed. Aerial photograph and satellite image observations improve the morphological analysis. The synoptic view which is offered by this analysis allowed for recognition and localization of the main volcanic and tectonic features of the area. On the basis of digital elevation model value distribution and surface textures, five morphological domains were defined. The most interesting domain, south of the crater, reflects the occurrence of an ancient complex volcano distinct from the adjacent areas. Interaction between the volcanic and volcano– tectonic evolution and the basement produced the other domains. Single volcanic edifices, like lava domes and scoria cones, and eruptive fractures were recognized. Finally, flank collapse scarps opened to the east and to the north were identified and four relevant morphostructural lineaments and their possible role in the Nevado de Toluca geological and structural evolution are discussed.278 29 - PublicationRestrictedUnderstanding eruptive style variations at calc-alkaline volcanoes: the 1913 eruption of Fuego de Colima volcano (Mexico)The 1913 sub-Plinian eruption of Fuego de Colima volcano (Mexico) occurred after almost 100 years of effusive and (minor) Vulcanian explosive activity, which modulated dome growth and destruction. Dome extrusion persisted from 1869 to 1913. The transition to explosive eruption started on 17 January 1913, and it progressed in three phases: (1) opening, with the generation of block-and-ash flows, (2) vent clearing, with strong explosions that destroyed the summit dome and decompressed the magmatic system, and (3) sustained column (sub-Plinian fallout) with final collapse producing pyroclastic density currents. Because of this succession of events, the 1913 activity represents an excellent case-study for investigating the eruptive style changes at calc-alkaline volcanoes. We investigated the conditions that led to eruptive style transition from effusive (dome growth) to explosive (the final sub-Plinian fallout) through steady-state numerical simulations, using subsurface data and independently inferred (from volcanological data) mass discharge rates as constraints. Results show good matches for hybrid geometrical settings of the shallow conduit-feeding system (i.e., dyke developing into a shallower cylindrical conduit), and the magma chamber top at 6 km of depth. The fragmentation level was shallower than 2 km, as inferred from the lithics contained in the sub-Plinian fall deposits of Phase (3). The most likely solution is represented by a dyke having major axis between 200 and 2000 m and the minor axis of 40 m. The dyke-cylinder transition was set at a depth of 500 m, with a cylinder diameter of 40 m. It emerges that at least two main mechanisms may be responsible for the effusive to explosive transition that led to the Phase (3) of the 1913 eruption: (i) an increase in magma chamber overpressure (magmatic triggering) or (ii) decrease of lithostatic stress acting on the volcano (non-magmatic triggering). The former implies arrival into the magma chamber of a batch of fresh magma, which can have volume between 10 and 200 × 106 m3, depending on the values of magma and host rock compressibility. The latter requires decompression-induced emptying of at least the equivalent of 1000 m of the magma column to produce the necessary unloading of the conduit-feeding system. A sudden jerk in the lateral spreading of the Fuego de Colima cone would be a reliable mechanism for decompressing the upper conduit and driving fragmentation processes over a time period of few hours. The results are not conclusive on an internal (magma chamber overpressure), external (lowering of lithostatic load), or mixed (internal and external) trigger of the observed eruptive style transition. This work highlights how different processes can have non-linear cascade effects on close-to-equilibrium volcanic systems like Fuego de Colima volcano.
69 2 - PublicationOpen AccessCyclic activity of the Fuego de Colima volcano (Mexico): insights from satellite thermal data and nonlinear modelsThe Fuego de Colima volcano (Mexico) shows a complex eruptive behavior, with periods of rapid and slow lava dome growth punctuated by explosive activity. We reconstructed the weekly discharge rate average between 1998 and 2018 by means of satellite thermal data integrated with published discharge rate data. By using spectral and wavelet analysis, we found a multiyear long-term, multi- month intermediate-term, and multi-week short-term cyclic behavior during the period of the investigated eruptive ac- tivity like that of many other dome-forming volcanoes. We use numerical modeling in order to investigate the nonlinear cyclic eruptive behavior considering a magma feeding sys- tem composed of a dual or a single magma chamber con- nected to the surface through an elastic dyke developing into a cylinder conduit in the shallowest part. We investigated cases in which the periodicity is controlled by (i) the cou- pled deep–shallow magma reservoirs, (ii) the single shallow chamber, and (iii) the elastic shallow dyke when it is fed by a fixed influx rate or constant pressure. Due to the limitations of the current modeling approach, there is no single config- uration that can reproduce all the periodicities on the three different timescales. The model outputs indicate that the ob- served multiyear periodicity (1.5–2.5 years) can be described by the fluctuations controlled by a shallow magma chamber with a volume of 20–50 km3 coupled with a deep reservoir of ca. 500 km3, connected through a deep elastic dyke. The multi-month periodicity (ca. 5–10 months) appears to be con- trolled by the shallow magma chamber for the same range of volumes. The short-term multi-week periodicity (ca. 2.5– 5 weeks) can be reproduced considering a fixed influx rate or constant pressure at the base of the shallower dyke. This work provides new insights on the nonlinear cyclic behavior of Fuego de Colima and a general framework for comprehen- sion of the eruptive behavior of andesitic volcanoes.
99 30 - PublicationRestrictedTephra fallout hazard assessment for a Plinian eruption scenario at Volcán de Colima (Mexico)(2011)
; ; ; ; ; ;Bonasia, R.; Centro de Geociencias, Universidad Nacional Autonoma de México, Campus Juriquilla, 76230 Queretaro, Mexico ;Capra, L.; Centro de Geociencias, Universidad Nacional Autonoma de México, Campus Juriquilla, 76230 Queretaro, Mexico ;Costa, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Macedonio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Saucedo, R.; Universidad Autónoma de San Luis Potosí, Instituto de Geología/Fac. Ingenieria, San Luis Potosí, Mexico; ; ; ; Volcanic ash fallout associated with renewal of explosive activity at Colima, represents a serious threat to the surrounding urbanized area. Here we assess the tephra fallout hazard associated with a Plinian eruption scenario. The eruptive history of Volcán de Colima shows that Plinian eruptions occur approximately every 100 years and the last eruption, the 1913, represents the largest historic eruption of this volcano. We used the last eruption as a reference to discuss volcanic hazard and risk scenarios connected with ash fallout. Tephra fallout deposits are modeled using HAZMAP, a model based on a semi-analytical solution of the advection– diffusion–sedimentation equation for volcanic particles. Based on a statistical study of wind profiles at Colima region, we first reconstructed ash loading maps and then computed ground load probability maps for different seasons. The obtained results show that a Plinian eruptive scenario at Volcán de Colima, could seriously damage more than 10 small towns and ranches, and potentially affect big cities located at tens of kilometers from the eruptive center. The probability maps obtained are aimed to give support to the risk mitigation strategies.201 17 - PublicationRestrictedNumerical simulation of tephra transport and deposition of the 1982 El Chichón eruption and implications for hazard assessment(2012)
; ; ; ; ; ;Bonasia, R.; Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, 76230 Queretaro, Mexico ;Costa, A.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Folch, A.; Barcelona Supercomputing Center-Centro Nacional de Supercomputación, Barcelona, Spain ;Macedonio, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia ;Capra, L.; Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, 76230 Queretaro, Mexico; ; ; ; El Chichón volcano, Chiapas, Mexico, erupted explosively on March 29th, 1982, after a repose period of about 550 years. Amongst ten eruptive episodes documented between March 29th and April 4th, only the three that occurred on March 29th and April 4th produced significant pyroclastic tephra deposits. Here we use analytical (HAZMAP) and numerical (FALL3D) tephra transport models to reconstruct the deposits and the atmospheric plume dispersal associated with the three main fallout units of the 1982 eruption. On the basis of such a reconstruction, we produce hazard maps of tephra fallout associated to a Plinian eruption and discuss the implications of such a severe eruption scenario.313 20