Geology topics

Maurizio Battaglia

Publications and source records attributed to Maurizio Battaglia.

At least 19 recordsLinked to original sources

USGS2026

dMODELS, a MATLAB software package for modeling crustal deformation near volcanic centers and active faults using Global Navigation Satellite System data—User guide

dMODELS is a MATLAB software package that implements the most common analytical models used to interpret deformation measurements near faults and active volcanic centers. This manual focuses on inversion of deformation data from the Global Navigation Satellite System (GNSS). The included case studies emphasize the GNSS inversion component of the software. Source models include pressurized spherical, spheroidal, and horizontal sill (penny-crack) magma reservoirs in a homogeneous, elastic, isotropic, flat half-space. A topography correction is available for the spherical source. Dikes and faults are described following the mathematical notation for the rectangular dislocations in a homogeneous, elastic, flat half-space. Equations have been reviewed for typographical errors present in the original literature and verified against finite-element method numerical models. GNSS data from the 2006 eruption at Augustine Volcano, Alaska; the 1998–2000 unrest at Taal Volcano, Philippines; and the 2009 earthquake in L’Aquila, Italy, are used to demonstrate the application of the software package.

Techniques and Methods↗

USGS2026

Role of volcano-tectonic interactions during early-phase magma-assisted continental rifting

We study volcanic-tectonic interactions during the early phase of rifting in the Natron Rift, a magmatic segment of the East African Rift System. We use the open-source crustal deformation modeling code, PyLith, to model deflation during the 2007–2008 explosive eruptions and inflation during 2016–2023. We compare predictions of surface displacements resulting from magma reservoir inflation from 3D models with and without topography and homogeneous and heterogeneous material properties against Global Navigation Satellite System displacements from 2016 to 2023. We prefer the model with heterogeneous material properties and topography for fitting the observed displacements. Including topography improves the fit to GNSS data and modulates stress changes from shallow magma sources. Our numerical modeling of Coulomb stress changes suggests that deflation of a magma reservoir under the active Ol Doinyo Lengai volcano could trigger oblique normal slip on the Natron Fault with Coulomb stress increases exceeding ∼0.1 MPa on the volcano-adjacent fault segment. Fault slip on the Natron Fault is less likely during inflation of the magma reservoir because normal compressive stress increases on the fault. We also demonstrate that Coulomb stress changes are sensitive to the inclusion of topography in our model, particularly because the depth of the magma reservoir is similar to the amplitude of the topographic relief.

Ol Doinyo Lenga↗

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↗

USGS2024

Geodetic monitoring of the recent activity and the dome forming eruption at Nevado del Ruiz (Colombia), 2010–2023

Nevado del Ruiz (Colombia) is infamous for the catastrophic eruption of 1985 that destroyed the villages of Armero and Chinchiná. However, this was not the volcano’s first destructive event; similar eruptions also occurred in 1595 and 1845. In 1985, the limited geodetic data available failed to provide a clear warning of the impending eruption. Since then, advancement in geodetic monitoring, now incorporating tilt and satellite geodesy, along with improvements in seismic, geochemical, geological and remote sensing monitoring, have enhanced hazards assessment and mitigated the risk during subsequent eruptions in 1989, 2012, and 2015–2019, as well as during periods of unrest over the last 13 years. Modeling of deformation data over the past 13 years reveals complex interactions between the local, shallow magmatic system beneath Nevado del Ruiz and a deep, regional magmatic system beneath Nevado de Santa Isabel, 9 km southwest of Nevado del Ruiz. Before February 2012, the volcano deflated because of the depressurization of the local shallow reservoir. This same reservoir later fueled ash emissions and gas release (2012–2023), and a dome-forming eruption (2015–2019). In contrast, the inflation observed from 2012 to 2023 is linked to the pressurization of the deep reservoir beneath the Nevado de Santa Isabel.

Nevado del Ruiz↗

USGS2023

Elucidating the magma plumbing system of Ol Doinyo Lengai (Natron Rift, Tanzania) Using satellite geodesy and numerical modeling

Ol Doinyo Lengai, located in the southern Eastern Branch of the East African Rift had several eruptive episodes with ash falls and lava flows (VEI 3) that caused damage to the nearby communities between 2007 and 2010. The volcano is remote and access is difficult. Although this volcano has been studied for decades, its plumbing system is still poorly understood, in part, because of the lack of precise observations of surface deformation during periods of quiet and unrest. This study investigates the volcanic plumbing system of Ol Doinyo Lengai and its surroundings using data from the network of permanent Global Navigation Satellite System (GNSS) sites monitoring the volcano (the TZVOLCANO network) around the flanks of the volcano and Interferometric Synthetic Aperture Radar (InSAR) observations. We constrain surface motions using 6 GNSS sites distributed around Ol Doinyo Lengai, operating between 2016 and 2021, and InSAR data covering nearly the same time period. Because of the complex local tectonics, the interpretation of the deformation pattern is not straightforward. We first invert the GNSS deformation and InSAR observations independently to infer potential deformation sources. Then we perform a joint inversion of both GNSS and InSAR datasets to verify our findings. We compare the results from the joint inversion with the results from inverting each dataset independently. The GNSS, InSAR, and joint inversion results point to a deflating source, located east of Ol Doinyo Lengai and southwest of the dormant volcano Gelai at a depth of 3.49 ± 0.03 km (GNSS inversion), 5.2 ± 1.2 km (InSAR inversion) and 3.49 ± 0.06 km (joint inversion) relative to the summit (vent) and with a volume change ∆V of −0.04 ± 0.05 × 10 6 m 3 (GNSS inversion), −0.39 ± 0.29 × 10 6 m 3 (InSAR inversion), and − 0.04 ± 0.01 × 10 6 m 3 (joint inversion). Although this is non-unique modeling of geodetic datasets with small signals, the inversion results suggest that Ol Doinyo Lengai could be fed by an offset multi-reservoir system that includes a shallow magma reservoir (<5 km) east of Ol Doinyo Lengai, possibly connected to a deeper magma reservoir.

Natron Rift, Ol Doinyo Lengai↗

USGS2022

gTOOLS, an open-source MATLAB program for processing high precision, relative gravity data for time-lapse gravity monitoring

gTOOLS is an open-source software for the processing of relative gravity data. gTOOLS is available in MATLAB and as a compiled executable to be run under the free MATLAB Runtime Compiler. The software has been designed for time-lapse (temporal) gravity monitoring. Although programmed to read the Scintrex CG-5 and CG-6 gravimeters output data files, it can be easily modified to read data files from other gravimeters. The software binds together single-task processing modules within a very simple user interface that is based on one text file. Gravity processing involves three modules: (a) gravimeter calibration; (b) automatic processing of gravity data to find adjusted gravity differences; and (c) post processing of results. Each module is optional and runs independently from the others. Data processing includes (a) averaging out the measurements noise, and correction for solid Earth tides, and ocean loading, and residual instrumental drift, and (b) calculate the residual instrumental drift and gravity differences between the base station and monitoring sites, and their uncertainties, by a weighted least square analysis of the gravity data. The software allows the automatic processing of a gravity campaign spanning multiple days in a single run. The software is tested on gravity data from 2015 eruption at Cotopaxi volcano, Ecuador.

Computers & Geosciences↗

USGS2022

Volcanic unrest at Nevados de Chillán (Southern Andean Volcanic Zone) from January 2019 to November 2020, imaged by DInSAR

The volcanic complex of Nevados de Chillán, located in the Southern Volcanic Zone (SVZ) of the Andes, has been active for the past 640 ± 20 ka. Its volcanic activity includes dome forming eruptions, explosive events, and lava flows. The most recent eruption cycle started in January 2016. We employ DInSAR time-series from Sentinel-1 data to investigate the unrest episode from January 2019 to November 2020. Two distinct periods of unrest are recognized in the time series. The first period (from January to October 2019) coincides with explosive events, dome growth inside the active crater, and a decrease in seismic activity but does not present a significant deformation. The second period (October 2019 to November 2020) is characterized by a displacement towards the sensor's line-of-sight of 100–120 mm. The observed surface deformation is compatible with an inflation source approximately 1.5 km south-southwest of the present active vent, at 5.5 ± 0.5 km depth from the surface, and with a volume change of 0.044 ± 0.014 km 3 . The most likely explanation for the observed inflation of Nevados de Chillan is the intrusion of magma in a reservoir feeding the current eruption cycle.

Nevados de Chillan↗

USGS2022

The new lava dome growth of Nevado del Ruiz (2015–2021)

The morphology of the summit of Nevado del Ruiz volcano (Colombia) and its active Arenas crater is the product of complex interactions between effusive and explosive eruptions, and the dynamics of the summit glacier. Here, we document the morphologic evolution of the summit of Nevado del Ruiz, and the growth of its dome, from a variety of methods: monitoring data (2010 to 2021), photogrammetry, remote sensing, and quantitative modeling. The present morphology of Arenas crater, with small terraces limited by the walls of the crater, various vents of ash emission, and zones of fumarolic activity, has been shaped by the activity following the eruptions of 1845, 1985, 1989, 2012 and the volcanic unrest of the last 10 years. The latest emplacement of a lava dome at the bottom of the main crater began in 2015. The dome grew, with fluctuations in its extrusion rate between ~0.19 m 3 /s (November 2015) and 0.02 m 3 /s (February 2018), until December 2019, reaching a diameter of ~130 m, a maximum height of ~60 m, and a volume of 1.7 ± 0.2 × 10 6 m 3 .

Nevado del Ruiz volcano↗

USGS2021

A new analysis of caldera unrest through the integration of geophysical data and FEM modeling: The Long Valley caldera case study

The Long Valley Caldera, located at the eastern edge of the Sierra Nevada range in California, has been in a state of unrest since the late 1970s. Seismic, gravity and geodetic data strongly suggest that the source of unrest is an intrusion beneath the caldera resurgent dome. However, it is not clear yet if the main contribution to the deformation comes from pulses of ascending high-pressure hydrothermal fluids or low viscosity magmatic melts. To characterize the nature of the intrusion, we developed a 3D finite element model which includes topography and crust heterogeneities. We first performed joint numerical inversions of uplift and Electronic Distance Measurement baseline length change data, collected during the period 1985–1999, to infer the deformation-source size, position, and overpressure. Successively, we used this information to refine the source overpressure estimation, compute the gravity potential and infer the intrusion density from the inversion of deformation and gravity data collected in 1982–1998. The deformation source is located beneath the resurgent dome, at a depth of 7.5 ± 0.5 km and a volume change of 0.21 ± 0.04 km 3 . We assumed a rhyolite compressibility of 0.026 ± 0.0011 GPa −1 (volume fraction of water between 0% and 30%) and estimated a reservoir compressibility of 0.147 ± 0.037 GPa −1 . We obtained a density of 1856 ± 72 kg/m 3 . This density is consistent with a rhyolite melt, with 20% to 30% of dissolved hydrothermal fluids.

California↗

USGS2021

The 2008-2010 subsidence of Dallol volcano on the 2 spreading Erta Ale ridge: InSAR observations and source models

In this work, we study the subsidence of Dallol, an explosive crater and hydrothermal area along the spreading Erta Ale ridge of Afar (Ethiopia). No volcanic products exist at the surface. However, a diking episode in 2004, accompanied by dike-induced faulting, indicates that Dallol is an active volcanic area. The 2004 diking episode was followed by quiescence until subsidence started in 2008. We use InSAR to measure the deformation, and inverse, thermoelastic and poroelastic modelling to understand the possible causes of the subsidence. Analysis of InSAR data from 2004–2010 shows that subsidence, centered at Dallol, initiated in October 2008, and continued at least until February 2010 at an approximately regular rate of up to 10 cm/year. The inversion of InSAR average velocities finds that the source causing the subsidence is shallow (depth between 0.5 and 1.5 km), located under Dallol and with a volume decrease between −0.63 and −0.26 × 10 6 km 3 /year. The most likely explanation for the subsidence of Dallol volcano is a combination of outgassing (depressurization), cooling and contraction of the roof of a shallow crustal magma chamber or of the hydrothermal system.

Dallol 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

Editorial: Synthetic Aperture Radar and natural hazards: Applications and outlooks

The ability of Synthetic Aperture Radar (SAR) to image the Earth’s surface, even through dense cloud cover and in night-and-day conditions, can facilitate the evaluation and monitoring of natural hazards and the management of natural disasters. The family of SAR satellite sensors orbits the Earth at an altitude ranging from 500 to 800 km, following sun-synchronous, near-polar orbits, slightly inclined with respect to Earth meridians. The most commonly used bands in SAR applications are the C-band (5–6 GHz, ~5,6 cm wavelength), the X-band (8–12 GHz, ~3,1 cm wavelength) and the L-band (1–2 GHz ~23 cm wavelength) with a temporal resolution depending on the satellite revisiting time. The availability of SAR has made a new spectrum of measurements possible on a global and spatial scale not attainable by ground-based studies, revealing critical insights into remote or poorly understood areas (e.g., Biggs et al., 2014). This Research Topics presents a review of articles on the state-of-art in the application of SAR sensors to study surface deformation in different geologic environments and triggered by a variety of processes. The topics discussed range from the analysis of co-seismic deformation (Marryman Boncori) to studies of volcanic unrest (Dzurisin et al., Garthwaite et al.), monitoring of landslides (Bianchini et al.) and ground subsidence in urban areas (Solari et al.).

Frontiers in Earth Science↗

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↗

USGS2019

Twenty years (1990–2010) of geodetic monitoring of Galeras volcano (Colombia) from continuous tilt measurements.

Galeras - an andesitic stratovolcano part of the Galeras Volcanic Complex - is one of the most active volcanoes in Colombia. Historic activity is centered on a small-volume cone inside the youngest amphitheater, which breaches the west flank of the volcano. At least 30 confirmed eruption periods have been recorded in the past 480 years, with episodes of unrest ranging from weak fumarolic activity and ash emissions to larger explosive events. The most recent eruption periods, recorded instrumentally since 1988, have been characterized by minor explosive eruptions, and the emplacement of three crater domes and small pyroclastic flow deposits. In this paper, we discuss the evolution of volcanic activity using a 20-year-long record of tilt measurements. In particular, we focus on three episodes of unrest occurred in 1991, 2006 and 2008, when the deformation was clearly associated with shallow magma intrusions, and the emplacement and destruction of crater domes. The depth of the intrusions varied from a few hundred meters (August 2005) to two kilometers (January 2009), while the volume change ranged from 104 m3 (May–October 2009) to 106 m3 (January 2009). A comparison with seismic data indicates that the deformation sources were located within the cloud of hypocenters of the volcano-tectonic events. The lack of a clear correlation between the volume change (and depth) of the sources and the total SO2 flux could indicate that the unrest at Galeras was related to a larger intrusive event with only a small part of the magma erupted in the form of tephra and lava domes.

Galeras volcano↗

USGS2019

Construction of probabilistic event trees for eruption forecasting at Sinabung volcano, Indonesia 2013–14

Eruptions of Sinabung volcano , Indonesia have been ongoing since 2013. Since that time, the character of eruptions has changed, from phreatic to phreatomagmatic to magmatic explosive eruptions, and from production of a lava dome that collapsed to a subsequent thick lava flow that slowly ceased to be active, and later, to a new lava dome. As the eruption progressed, event trees were constructed to forecast eruptive behavior six times, with forecast windows that ranged from 2 weeks to 1 year: November 7–10, December 12–14, and December 27, 2013; and January 9–10, May 13, and October 7, 2014. These event trees were successful in helping to frame the forecast scenarios, to collate current monitoring information, and to document outstanding questions and unknowns. The highest probability forecasts closely matched outcomes of eruption size (including extrusion of the first dome), production of pyroclastic density currents, and pyroclastic density current runout distances. Events assigned low probabilities also occurred, including total collapse of the lava dome in January 2014 and production of a small blast pyroclastic density current in February 2014.

Sinabung volcano↗

USGS2019

Hydrothermal fluid migration due to interaction with shallow magma: Insights from gravity changes before and after the 2015 eruption of Cotopaxi volcano, Ecuador

On August 14, 2015 Cotopaxi Volcano (Ecuador) erupted with several phreatomagmatic explosions after nearly 135 years of quiescence. Unrest began in April 2015 with an increase in the number of daily seismic events and inflation of the flanks of the volcano. Time-lapse gravity measurements started at Cotopaxi volcano in June 2015. Although minor gravity changes were detected prior to eruptive activity, however, the largest gravity variations at Cotopaxi were measured between October 2015 and March 2016, when other geophysical parameters had reached background levels. Inverse modelling of GPS data suggests a deep intrusion prior to the eruptive activity, while inverse modelling of post-eruptive gravity changes suggests variations in the volcano hydrothermal system. Deformation, seismicity, and gravity changes are consistent with the intrusion of a deep magmatic source between April and August 2015. Part of the magma rose from depth and interacted with the hydrothermal system, causing the phreatomagmatic activity and pushing hydrothermal fluids from a deep aquifer into a shallow perched aquifer.

Journal of Volcanology and Geothermal Research↗

USGS2018

Mass addition at Mount St. Helens, Washington, inferred from repeated gravity surveys

Measurements of subtle changes in the Earth’s gravityfield can provideinformation on the addition/loss of mass (e.g., magma or aqueousfluids) beneath a volcano. In this study, wemeasured gravity at Mount St. Helens from 2010 to 2016 to investigate possible mass changes followingthe 2004–2008 dome-forming eruption. The raw gravity measurements were corrected for changes in themass and shape of Crater Glacier and for deformation of the volcanic edifice to obtain residual gravity values.We found positive residual gravity changes that we interpret as evidence for partial recharge of the magmareservoir that fed the 2004–2008 eruption and/or for accumulation of groundwater in one or more shallowaquifers. Most of the gravity signal can be explained by groundwater accumulation; magma recharge is notrequired. However, there is additional evidence for at least partial recharge from seismic, deformation, andgeochemical observations

Washington↗