Browsing by Author "Apaza, Fredy"
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Item Restricted Advances in scientific understanding of the Central Volcanic Zone of the Andes: a review of contributing factors(Springer, 2022-02-12) Aguilera, Felipe; Apaza, Fredy; Del Carpio Calienes, José Alberto; Grosse, Pablo; Jiménez, Néstor; Ureta, Gabriel; Inostroza, Manuel; Báez, Walter; Layana, Susana; Gonzalez, Cristóbal; Rivera, Marco; Ortega, Mayra; Gonzalez, Rodrigo; Iriarte, RodrigoThe Central Volcanic Zone of the Andes (CVZA) has been the focus of volcanological research for decades, becoming a very important site to understand a number of volcanic processes. Despite most of the research in the CVZA being carried out by foreign scientists, the last two decades have seen a significant increase in contributions by regional researchers. This surge has been facilitated by the creation of new volcanic observatories, improvement of the monitoring networks, creation of postgraduate programs where new local volcanologists are trained, creation of specialized research nuclei or groups, and increasing investment in research. This article presents a review of the evolution of the contributions of the regional volcanological community to the knowledge of the CVZA in the last 20 years (2000–2019), both from research and monitoring institutions in Peru, Bolivia, Argentina, and Chile. Based on updates made by the regional groups, a new list of active/potentially active volcanoes of the CVZA is presented, as is a complete database for article published on the CVZA. We find that a significant motivator has been regional volcanic unrest that has triggered new investment. Perú is the country with the highest investment in monitoring and research and is the best instrumented, Argentina is the country with the highest number of local participation in published papers in the domain of volcanology and magmatic systems, and Chilean volcanoes are the focus of the highest number of articles published. The current situation and general projections for the next decade (2020–2030) are also presented for each country, where we believe that the over the next 10 years, will be increased the monitoring and research capabilities, improved the scientific knowledge with more participation of regional institutions, and strengthen the collaboration and integrated work between CVZA countries, especially in border volcanoes.Item Restricted Magma extrusion during the Ubinas 2013-2014 eruptive crisis based on satellite thermal imaging (MIROVA) and ground-based monitoring(Elsevier, 2015-09) Coppola, Diego; Macedo Sánchez, Orlando Efraín; Ramos Palomino, Domingo A.; Finizola, Anthony; Delle Done, Dario; Del Carpio Calienes, José Alberto; White, Randall; McCausland, Wendy; Centeno Quico, Riky; Rivera, Marco; Apaza, Fredy; Ccallata, Beto; Chilo, Wilmer; Cigolini, Corrado; Laiolo, Marco; Lazarte, Ivonne; Machaca, Roger; Masias, Pablo; Ortega, Mayra; Puma Sacsi, Nino; Taipe, EduAfter 3 years of mild gases emissions, the Ubinas volcano entered in a new eruptive phase on September 2nd, 2013. The MIROVA system (a space-based volcanic hot-spot detection system), allowed us to detect in near real time the thermal emissions associated with the eruption and provided early evidence of magma extrusion within the deep summit crater. By combining IR data with plume height, sulfur emissions, hot spring temperatures and seismic activity, we interpret the thermal output detected over Ubinas in terms of extrusion rates associated to the eruption. We suggest that the 2013–2014 eruptive crisis can be subdivided into three main phases: (i) shallow magma intrusion inside the edifice, (ii) extrusion and growing of a lava plug at the bottom of the summit crater coupled with increasing explosive activity and finally, (iii) disruption of the lava plug and gradual decline of the explosive activity. The occurrence of the 8.2 Mw Iquique (Chile) earthquake (365 km away from Ubinas) on April 1st, 2014, may have perturbed most of the analyzed parameters, suggesting a prompt interaction with the ongoing volcanic activity. In particular, the analysis of thermal and seismic datasets shows that the earthquake may have promoted the most intense thermal and explosive phase that culminated in a major explosion on April 19th, 2014. These results reveal the efficiency of space-based thermal observations in detecting the extrusion of hot magma within deep volcanic craters and in tracking its evolution. We emphasize that, in combination with other geophysical and geochemical datasets, MIROVA is an essential tool for monitoring remote volcanoes with rather difficult accessibility, like those of the Andes that reach remarkably high altitudes.Item Open Access Observaciones de intranquilidad en el volcán Sabancaya iniciada el 22 de febrero de 2013(Instituto Geofísico del Perú, 2013) Macedo Sánchez, Orlando Efraín; Ramos, D.; Centeno Quico, Riky; Ticona, Javier; Masias, Pablo; Machacca, Roger; Aguilar, Victor; Taipe, Edu; Antayhua, Yanet; Paxi, R.; Anccasi, Rosa; Apaza, FredyEl 22 de Febrero 2013 en un lapso de solo 95 minutos han ocurrido 3 sismos de magnitudes 4.6, 5.2 y 5.0 ML en inmediaciones del volcán Sabancaya (15.78° S, 71.85°W, 5976 m, Fig 1), en el sur del Perú, causando destrucción de 18 viviendas en Maca, poblado situado en el valle del Colca, a 20 km al NE del cráter.Item Restricted Probing the hidden magmatic evolution of El Misti volcano (Peru) with the Pb isotope composition of fumaroles(Springer, 2022-01-20) Vlastelic, Ivan; Apaza, Fredy; Masias, Pablo; Rivera, Marco; Piro, Jean‐Luc; Gannoun, AbdelmouhcineThis work proposes a new method to probe the hidden magmatic evolution of quiescent Andean volcanoes from the Pb isotope composition of gases. The method is based on an assimilation-fractional crystallisation-degassing model linking the Pb isotope composition of gases with the SiO₂ content of their magmatic source. The model is applied to El Misti volcano that threatens Arequipa, the second most densely populated city of Peru. Gas condensates and Pb-rich solid deposits (PbS, PbCl₂, PbSO₄) collected in 2018 in the bottom of El Misti crater at 260–150°C fumarole vents were used to reconstruct the mean composition of degassing magmas (60.8-61.8 wt% SiO₂). These compositions are slightly more evolved than the lavas from the last AD 1440–1470 eruption, suggesting either the secular differentiation of the main magma reservoir, or the contribution of more evolved magmas to volcanic gases. On the other hand, the slight but significant difference between the instantaneous composition recorded in gas condensates and the time-integrated composition recorded in solid deposits points to the degassing of less evolved magmas over the last decades. This trend is ascribed to a recent recharge of El Misti reservoir with hot mafic magmas, in agreement with the evolution of fumarolic deposit mineralogy in the last half a century. The Pb isotope composition of gas appears to be a promising tool for probing the hidden magmatic evolution of quiescent volcanoes where assimilation-fractional crystallisation operates.