Geology topics

Pablo Euillades

Publications and source records attributed to Pablo Euillades.

4 recordsLinked to original sources

USGS2025

Contribución de la geodesia a la gestión del riesgo volcánico del Nevado del Ruiz

Nevado del Ruiz es uno de los volcanes más activos de Colombia. Adquirió una trágica notoriedad a causa de la devastadora erupción ocurrida en noviembre de 1985, que provocó la destrucción de la población de Armero. Desafortunadamente, los limitados datos de deformación recopilados en ese momento no proporcionaron una advertencia clara de la inminente erupción. Desde 1985, el seguimiento del volcán Nevado del Ruiz ha experimentado importantes avances. La integración del monitoreo geodésico con observaciones sísmicas, geoquímicas y geológicas ha mejorado la comprensión del comportamiento del volcán, fortaleciendo la evaluación de los peligros volcánicos y reduciendo significativamente el riesgo volcánico. Gracias a la información disponible en tiempo real sobre el estado del volcán y al trabajo continuo de profesionales experimentados, el Nevado del Ruiz ha dejado de ser reconocido por un desastre, transformándose en un ejemplo notable de gestión eficaz del riesgo volcánico.

El Nevado del Ruiz volcano↗

USGS2021

Monitoring volcanic deformation

Deformation signals recorded at volcanoes have long been used to infer the processes behind subsurface magma intrusions. Monitoring strategies vary greatly depending on several factors such as the activity of the individual volcano, access, available personnel, and funding. Certain geodetic monitoring methods, such as Electronic Distance Measurements, are inexpensive but require that scientists be dangerously close to active areas. Other techniques, such as telemetered geodetic measurements (Electronic Tiltmeters and Global Navigation Satellite System), or deformation images from Interferometric Synthetic Aperture Radar, can be collected remotely and with less risk. Observed surface deformation can be fit to the predictions of mathematical source models to obtain quantitative estimates of their parameters (e.g., location, depth, volume change and more). Combined deformation and gravity change measurements can be used to infer the density of subsurface intrusions and better constrain the source of unrest. To be effective, geodetic monitoring must be done before, during, and after eruptions and must be integrated with other monitoring techniques (e.g., seismology, geochemistry, physical volcanology, remote sensing). It requires the long-term commitment of time and resources. Done effectively, geodetic monitoring not only can provide timely warnings of escalating volcano hazards but may also lead to improved understanding of how volcanoes work. Even when a volcano is not active, monitoring generates baseline information against which changes in volcano behavior can be compared. Preserving the integrity and accessibility of geodetic data archives is thus essential if future volcanologists are to benefit from the decades-long records of geodetic data gathered by volcano observatories.

Book chapter↗

USGS2020

Source model for Sabancaya volcano constrained by DInSAR and GNSS surface deformation observation

Sabancaya is the most active volcano of the Ampato-Sabancaya Volcanic Complex (ASVC) in southern Perú and has been erupting since 2016. The analysis of ascending and descending Sentinel-1 orbits (DInSAR) and Global Navigation Satellite System (GNSS) datasets from 2014 to 2019 imaged a radially symmetric inflating area, uplifting at a rate of 35 to 50 mm/yr and centered 5 km north of Sabancaya. The DInSAR and GNSS data were modeled independently. We inverted the DInSAR data to infer the location, depth, and volume change of the deformation source. Then, we verified the DInSAR deformation model against the results from the inversion of the GNSS data. Our modelling results suggest that the imaged inflation pattern can be explained by a source 12 to 15 km deep, with a volume change rate between 26 × 10 6 m 3 /yr and 46 × 10 6 m 3 /yr, located between the Sabancaya and Hualca Hualca volcano. The observed regional inflation pattern, concentration of earthquake epicenters north of the ASVC, and inferred location of the deformation source indicate that the current eruptive activity at Sabancaya is fed by a deep regional reservoir through a lateral magmatic plumbing system.

Sabancaya volcano↗

USGS2019

Monitoring volcanic deformation

Whereas research in volcano geodesy seeks to push the boundaries of our knowledge of the physics of volcanoes, monitoring looks at changes in volcano behavior to predict when a volcanic crisis might develop. To be effective, geodetic monitoring must be done before, during, and after eruptions and must be integrated with other monitoring techniques . It requires the type of long-term commitment of time and resources that academic and industry scientists generally cannot make. A few, well-placed geodetic monitoring stations can make a huge difference to a country's ability to alert its people to an imminent volcanic eruption . Monitoring strategies vary greatly depending on several factors such as the activity of the individual volcano, access, and available personnel and funding. Rapid advances in technology allow for more precise geodetic monitoring today than was imaginable when many of the existing volcano observatories were established. Today, deformation measurements at active volcanoes are usually made with continuous Global Positioning System (CGPS) stations, supplemented by Interferometric Synthetic Aperture Radar (InSAR) images. Neither method requires a continuous presence of personnel in the field, except for the installation and maintenance of the GPS stations; however subsequent data analysis can be highly complex.

Book chapter↗