Estimación del aporte hídrico de las crioformas de la subcuenca del río Hurtado, región de Coquimbo, Chile

Informe Registrado IR-24-115156 p

Resumen de estado de remoción en masa : Descripción de la remoción en masa de tipo deslizamiento observada en mayo 2024

Minuta ATG Flash Los Lagos 01/20241 p

Susceptibilidad de remociones en masa en la provincia de Palena, región de Los Lagos, Chile

Informe Registrado IR-24-11894 p

Informe de observaciones de terreno socavones al suroeste de Concón, comuna de Viña del Mar, 19 de julio 2024

Informe Técnico -- Unidad Ejecutora: Unidad de Peligros Geológicos y Ordenamiento Territorial, Unidad de Asistencias Técnicas y Emergencias Geológicas, Santiago11 p

Geological mapping in the Argentine Frontal Cordillera (~30°30’ S) using ASTER images

The eastern flank of the Argentine Frontal Cordillera at ~30°30’ S is a remote area with rugged topography and high elevations that hinder geological field mapping. This task is also challenging because several outcrops are dominated by Permian-Triassic and Cenozoic volcanic rocks of intermediate to acid compositions with scarce geochronological age constraints. In this work, we use ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) data to clarify the structural and stratigraphic framework of the region. Visible and near infrared (VNIR) and shortwave infrared (SWIR) band combinations, integrated with field observations, are effective in identifying first-order geological features. In addition, the Semi-Automatic Classification Plugin (SCP; a free open-source plugin for QGIS) is capable of discriminating lithological units and is especially useful to visualize their distribution. Results presented here allow us to characterize Permian-Triassic and Cenozoic units, propose tentative correlations between the Permian-Triassic rocks, and outline major tectonic structures in the study area. This work demonstrates the capability of ASTER data to improve geological mapping, especially in those places where field work is difficult.pp.330-35

Visita a rutas G-25 sector Las Achupallas y G-345 sector Los Maitenes, comuna de San José de Maipo, Región Metropolitana

Informe Técnico -- Unidad Ejecutora: Unidad de Asistencias Técnicas y Emergencias Geológicas, Santiago14 p

Seguimiento al evento de remoción en masa en Población Marchant, comuna de Coyhaique, región de Aysén del General Carlos Ibáñez del Campo

Informe Técnico -- Unidad Ejecutora: Dirección Regional de Aysén, Unidad de Asistencias Técnicas y Emergencias Geológicas14 p

The Andean Southern Volcanic Zone : A review on the legacy of the latest volcanic eruptions

The Andean Southern Volcanic Zone (SVZ) concentrates many of the most active volcanoes of the Andean continental arc, as well as the region’s most recent and impactful volcanic eruptions. In this contribution, we briefly revise the general characteristics of the SVZ volcanism and provide a synthesis of the scientific findings related to the latest volcanic eruptions (430 peer-reviewed publications with over 9,000 citations, with large-magnitude (VEI 4-5) eruptions being the most studied. Our study shows that SVZ research has been primarily focused on environmental and atmospheric impacts (29%), eruption descriptions and physical volcanology (20%), volcanic hazard and risk assessments (15%), and other investigations complementary to volcanology. Whereas the least silicic eruptions (e.g., Llaima 2008-2009 and Villarrica 2015) shed light on magma replenishment and degassing dynamics controlling eruption styles, intermediate eruptions (andesitic-dacitic) offered clues on either rapid or slow eruption initiation, with relevant findings on phreatic-to-magmatic style transitions and eruption triggering mechanisms. On the other hand, silicic (i.e., rhyolite-rhyodacite) eruptions provided unique observations on rapid magma ascent, high-rate magma extrusion, rheology, fragmentation processes, and style transitions. These recent eruptions have also inspired a new generation of tephrochronological, tephrostratigraphical, and physical volcanology studies, aimed at assessing the long-term (kyr-scale) evolution of the volcanic systems and their associated hazards. We debate how the knowledge gained from research and the long-term human coexistence with volcanoes are relevant to reducing volcanic risk in the SVZ. Finally, we discuss how challenges and opportunities emerging from other disciplines can complement our understanding of volcanism in this active region.pp.379-41

Altered intrusive rock detection through electrical resistivity tomography : The case of the San Luis area, Central Panama

This work investigates the potentiality of the 2D electrical resistivity tomography method to delineate an altered intrusive rock domain. The detection and characterization of such altered domains are crucial to understanding local hydrogeological conditions. Here, the target is the San Luis area, located in the northern part of the Estibaná River watershed, within the Los Santos Province in the central region of the Isthmus of Panama. First, a detailed geological survey was carried out to better constrain the tectonic structures. Then, two geological sections were developed based on two 2D electrical resistivity tomographies. A geoelectrical simulation process was conducted in both sections to set theoretical models whose model responses (synthetic field data set) would be consistent with the observations. After appropriate selection of the inversion parameters by using the Boundless Electrical Resistivity Tomography (BERT) code, the observations were processed, resulting in low calculation errors (2 < 0.51). Based on the superficial geological information and the results of the geophysical modelling, two profiles were established, depicting the lateral and in-depth distribution of rocks and sediments. The limit of the Ocú-Parita fault zone was identified as well. The results of the 2D inversion of the synthetic data, obtained with the established theoretical models, are consistent with the 2D inversion of the observations. Electrical resistivity tomography studies can be useful in establishing groundwater management models, particularly in areas that experience severe water scarcity during the dry season.pp.475-48

Evaluación de remociones en masa sector predio Casa Piedra, comuna de El Carmen, región del Ñuble

Informe Técnico -- Unidad Ejecutora: Unidad de Asistencias Técnicas y Emergencias Geológicas, Concepción7 p