Repositorio Digital Sernageomin
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Antecedentes geológicos de remociones en masa en Caleta El Manzano, Villa Santa Lucía y dos sectores en Futaleufú, Provincia de Palena, Región de Los Lagos
No full textInforme Técnico -- Unidad Ejecutora: Dirección Regional Los Lagos29 p
Estadísticas de Accidentabilidad Industria Extractiva Minera Año 2024 : Reporte al 31 de Mayo 2024
No full textDepartamento de Investigación de Accidentes y Sanciones18 p
Estimación del aporte hídrico de las crioformas de la subcuenca del río Hurtado, región de Coquimbo, Chile
No full textInforme Registrado IR-24-115156 p
Evolution of the Tumaco, Atrato, and San Juan basins on a continuous platform along the colombian pacific margin
No full textSeveral authors have interpreted the Colombian Pacific margin as a succession of oceanic terrane accretions, with generation of forearc basins under a compressive-transpressive tectonic regime during the Late Cretaceous-Miocene. New data acquired in the last decade, consisting of reprocessed seismic lines, geological cross-sections, stratigraphic data from wells, and new stratigraphic columns, are analyzed in this study. We suggest that the proposed models of successive terrane accretions are not supported by the new data; rather, the onshore basins were likely controlled by a marine platform from the Late Cretaceous to the Middle-Late Eocene, with reef growth to the end of this period. In the Late Cretaceous, contemporary to the sedimentation stage, effusive magmatism, mainly basaltic, also occurred. Since Oligocene time, the basins were affected by three different tectonic processes. First, during the Oligocene-Early Miocene, an extensional-transtensional event occurred in the Tumaco Basin and San Juan Sub-basin, which produced horst and graben structures and domino faults, along with the emplacement of igneous bodies in the eastern flank of the basins. The Atrato Sub-basin was affected by local reverse faulting towards its eastern edge. Second, during the Mid-Late Miocene, the western side of the Tumaco Basin was uplifted, and transpressive deformation occurred in the San Juan Sub-basin as evidenced by the San Juan and Garrapatas fault systems. Finally, in the Atrato Sub-basin, a transpressional regime is evidenced by the Baudó anticline. Our results suggest there is no evidence of oceanic terrane accretions in the abovementioned basins during the Late Cretaceous-Middle Eocene. Furthermore, we do not see evidence of a subduction system during that period. We conclude that subduction in western Colombia could have begun during the Early Oligocene instead.pp.218-24
Antecedentes hidrogeológicos en el terreno destinado a Posta de Salud Rural en isla Caucahue, Comuna de Quemchi, Región de Los Lagos
No full textInforme Técnico -- Unidad Ejecutora: Dirección Regional Los Lagos10 p
Visita Técnica por deslizamiento. Sector Valle Hermoso, comuna de Puente Alto, región Metropolitana
No full textInforme Técnico -- Unidad Ejecutora: Unidad de Asistencias Técnicas y Emergencias Geológicas10 p
Antecedentes geológicos de remociones en masa en Caleta El Manzano, Villa Santa Lucía y dos sectores en Futaleufú, Provincia de Palena, Región de Los Lagos
No full textInforme Técnico -- Unidad Ejecutora: Dirección Regional Los Lagos29 p
Recent fluctuations of the Alerce glacier (1953-2020), North Patagonian Andes
No full textIn recent decades, glacier retreat has been observed in all the world’s mountain ranges. Over the last 20 years, glaciers in the Andes have lost mass at one of the highest rates on record. Particularly, glaciers in the northern Patagonian Andes show the highest rate of loss of all the Andean regions for the last decade. Detailed records of long-term variations in glacier extent are crucial to put current climate change into context and quantify its impact on mountain areas. In the present study, a reconstruction of the extension (length and area) of the Alerce glacier (41.15° S-71.81° W) for the last 70 years was carried out. By means of historical documents and satellite images (Landsat and Pléiades), detailed maps of glacier fluctuations were generated for the period 1953-2020. Four methodologies were evaluated to measure the front position: i) central flow line; ii) curvilinear box; iii) multiline; and iv) variable box. The magnitude of the front position variations depends on the methodology applied. The method that best addresses glacier front variations over the period analyzed is the variable box method. Between 1953 and 2020, the Alerce glacier lost 35% of its area (1.1±0.1 km2) and 67% of its total length (1.49±0.04 km). It is possible to distinguish periods with different rates of retreat. A stage of slight retreat (-11.3±0.5 ma-1) between 1953 and 1976, followed by a period of stability (-6.7±0.5 ma-1) between 1977 and 1983, then a strong retreat (-58.7±0.5 ma-1) between 1984 and 1999, followed by another period of stability (-5.4±0.5 ma-1) between 2000 and 2009 and, finally, another retreat (-8.7±0.5 ma-1) between 2010 and 2020. The retreat rates for the Alerce glacier mimic those observed in other glaciers in the region, possibly representing a regional climatic signal.pp.247-26
Living in-between : Implications of local risk perceptions for the management of future eruptions at the Calbuco and Osorno volcanoes (Ensenada, Chile)
No full textSince the perceptions of communities at risk play a central role in managing future emergencies, contingency plans must consider the appropriate involvement of the perspectives of exposed populations. This article addresses the case of Ensenada (Puerto Varas, Chile), a settlement located in the area of direct influence of the Calbuco and Osorno volcanoes. They respectively rank 2nd and 8th in the list of highest-threat Chilean volcanoes. Here we depict the multiple risk perceptions of the inhabitants of Ensenada and the integration of human perceptions into volcanic emergency management through qualitative research, based on semi-structured interviews and documentary analysis. Our results illustrate that Ensenada represents a settlement critically exposed to multiple hazards from both volcanoes, intertwined with a series of social conditions that influence individuals’ self-perception as vulnerable to future eruptions and, simultaneously, as capable of acquiring conditions to strengthen disaster preparedness. Moreover, the locals are eager to participate in future emergency management planning and adopt preventive attitudes at community, household, and individual levels. Based on these results, we highlight the advantages of a better understanding of the causes of perceived risk and its integration into emergency management strategies for future eruptions, in order to visualise how people make sense of daily life and disaster preparedness in the midst of active volcanoes.pp.63-8