Mauro Rosi - Academia.edu (original) (raw)
Papers by Mauro Rosi
Journal of Volcanology and Geothermal Research, Aug 1, 1999
Journal of Volcanology and Geothermal Research, Jun 1, 2002
Journal of Volcanology and Geothermal Research, Jul 1, 1990
Bulletin of Volcanology, Apr 19, 2016
Bulletin of Volcanology, May 19, 2021
Oceanography, Mar 1, 2012
. In this paper we present a new model for the simulation of lahars, based on the depth-averaged ... more . In this paper we present a new model for the simulation of lahars, based on the depth-averaged code IMEX-SfloW2D with new governing and constitutive equations introduced to better describe the dynamics of lahars. A thorough sensitivity analysis is carried out to identify the critical processes (such as erosion and deposition) and parameters (both numerical and physical) controlling lahar runout, using both synthetic and real cases topographies. In particular, an application of the model to a syn-eruptive lahar from a reference-size eruption from Somma-Vesuvius, affecting the Campanian Plain (Southern Italy), described in Di Vito et al. (this issue), is used in this work for the sensitivity analysis. Effects of erosion and deposition are investigated by comparing simulations with and without these processes. By comparing flow thickness and area covered by the flow and their evolution with time, we show that the modelling of both the processes is important to properly simulate the effects of the bulking and debulking and the associated changes in rheology. From a computational point of view, the comparison of simulations obtained for different numerical grids (from 25 m to 100 m), scheme order, and grain size discretization were useful to find a good compromise between resolution and computational speed. The companion paper by Sandri et al. (this issue) shows an application of the presented model for probabilistic volcanic hazard assessment for lahars from Vesuvius deposits in the Neapolitan area.
Scientific Reports
The most frequent volcanic eruptions are of low-intensity and small magnitude. They produce abund... more The most frequent volcanic eruptions are of low-intensity and small magnitude. They produce abundant ash-sized (< 2 mm) clasts, which are too small to establish quantitative links between magmatic processes and eruptive dynamics using classic approaches. This inhibits our ability to study the past behaviour of frequently erupting volcanoes, essential to predict their future activity and mitigate their impact. The Palizzi unit (10–13th century, Vulcano, Italy) includes a prototype sequence of ash deposits resulting from prolonged Vulcanian eruptions punctuated by those of two larger sub-Plinian events. We apply Hierarchical Clustering to chemical analyses of clinopyroxene collected along the stratigraphy to decipher magma dynamics during this eruptive period. We identify periods of magma input and we link deep magmatic processes to eruptive dynamics, also showing that our approach can be used to connect magma and eruptive dynamics in any volcanic sequence. This is essential to tra...
Bulletin of Volcanology
In 1999–2001, Guagua Pichincha volcano, Ecuador, produced a series of cyclic explosive and effusi... more In 1999–2001, Guagua Pichincha volcano, Ecuador, produced a series of cyclic explosive and effusive eruptions. Rock samples, including dense blocks and pumiceous clasts collected during the eruption sequence, and ballistic bombs later collected from the crater floor, provide information about magma storage, ascent, decompression, degassing, repressurization, and regassing prior to eruption. Pairs of Fe-Ti oxides indicate equilibrium within 1.2–1.5 log units above the NNO oxidation buffer and equilibrium temperatures from 805 to 905 °C. Melt inclusions record H2O contents of 2.7–4.6 wt% and CO2 contents (uncorrected for CO2 segregation into bubbles) from 19 to 310 ppm. Minimum melt inclusion saturation pressures fall between 69 and 168 MPa, or equilibration depths of 2.8 and 6.8 km, the lower end of which is coincident with the maximum inferred equilibration depths for the most vesicular breadcrust bombs sampled. Amphibole phenocrysts lack breakdown rims (except for one sample) and p...
Geological Society, London, Special Publications
Volcanoes produce probably the most spectacular geological phenomena on Earth. Any of their erupt... more Volcanoes produce probably the most spectacular geological phenomena on Earth. Any of their eruptions can have a strong consequence on the surrounding environment, often captured in great detail in the sedimentary records of volcanically active regions. In addition, flank landslides and background erosive processes affecting volcanic sequences release volcanic particles that circulate within sedimentary environments up to billions of years after their generation. Therefore, exploring volcanically influenced sedimentary environments is an exciting and challenging scientific exercise requiring insights across multiple geological disciplines, drawing upon an increasing varied range of expertise and analytical approaches from across the geoscientific community. This book aims to provide an updated collection of works that illustrate the state-of-the-art in this topic, and to define the future directions of the geological sciences in utilizing and interpreting sedimentary records of volc...
Geological Society, London, Special Publications
This book brings together research, review and methodological papers that provide an updated view... more This book brings together research, review and methodological papers that provide an updated view on the sedimentary record of volcanism, spanning diverse processes and environments. It aims to bridge the gap between volcanological and sedimentological approaches to the investigation of processes governing the generation, dispersion and accumulation of volcaniclastic deposits.
Lahars are rapid flows composed of water and volcaniclastic sediments, which have the potential t... more Lahars are rapid flows composed of water and volcaniclastic sediments, which have the potential to impact residential buildings and critical infrastructure as well as to disrupt critical services, especially in absence of a hazard-based land-use planning. Their destructive power is mostly associated with their velocity (related to flow rheology and surrounding topography) and to their ability to bury buildings and structures (related to the deposit thickness). The distance reached by lahars depends on their volume, on sediments/water ratio, as well as on the overall characteristics of the path where they propagate. Here we present a novel strategy for the assessment of risk associated with lahar inundation related both to flow velocity and deposit thickness using Vulcano island (Italy) as a case study. First, a range of hazard scenarios has been identified that are related to the mobilization by intense rain events of tephra fallout deposited on the slopes of the La Fossa cone by a ...
Annals of Geophysics, 2021
T The paper addresses the long-lasting human presence on the island of Stromboli, an active vol... more T The paper addresses the long-lasting human presence on the island of Stromboli, an active volcano at the northern edge of the Aeolian archipelago, in the Southern Tyrrhenian sea, Italy. A conceptual model has been built to explore the phenomenon, it takes into account a series of aspects comparing Stromboli to other islands: their morphology, natural resources and geography along with the archaeological and historical data and, further, human attitude to volcanic environments, to risk and to insularity has been deeply explored. We propose a complex narrative where a combination of geological, socio-economic, historical, and psychological factors influenced people’s choices and that human presence is related more to the volcanic (and island) environment (and opportunities) than to volcanic activity.
Annals of Geophysics, 2021
In 79 A.D. Vesuvius buried entire cities in a few days under a blanket of pumice and ashes. It... more In 79 A.D. Vesuvius buried entire cities in a few days under a blanket of pumice and ashes. It was a sudden event, which occurred after centuries of inactivity, heralded only by earthquakes that repeated periodically, for many years, creating addiction rather than alarm. After the event, the vegetation covered the volcanic products, and the memory of the disaster was lost. The first excavations began in Herculaneum in 1738 and in Pompeii ten years later, in times when archeology still did not exist. Much was destroyed, given away, thrown away. Almost intact buildings emerged, with all their contents, with many inhabitants caught on the run. The arduous process of recovering the sites has had important and not always happy stages, accompanied by continuous progress in the excavation methods. Volcanology has drawn from those experiences as much as it could, setting itself the goal of reconstructing the story of an explosive eruption, the first in the world to be described, by Plin...
Annals of Geophysics, 2021
The lava platform and the three pyroclastic cones of Vulcanello constitute the northernmost vo... more The lava platform and the three pyroclastic cones of Vulcanello constitute the northernmost volcanic structure of the island of Vulcano (Aeolian Islands). The sandy isthmus connecting the platform to the main island was definitively formed in the first half of the 1500s; before then, Vulcano and Vulcanello were two close but separate islands. For a long time, the interpretation of the sources of the II-I century BC, had considered the islet as built up about 2200 years ago. This belief, which proliferated among naturalists from the 17th century, is not confirmed in the ancient texts or even in the geographical documents of the time, which do not indicate the presence of Vulcanello as a new and stable island near Vulcano. The islet would only be mentioned at the dawn of the second millennium, and named in Arabic “Gabal’ al Burkān”, meaning Mount of Vulcano; shortly thereafter the toponym changed to the Latin “Insulam Vulcanelli” and then, towards the 15th century, finally to Vulca...
Conclusions • System geometry controls rise velocity, which in turn controls break-up • There is ... more Conclusions • System geometry controls rise velocity, which in turn controls break-up • There is a specific size to the bubbles a system of a certain size and geometry can deliver • Being able to measure that size (through geophysical techniques) we can invert it to infer upper conduit geometry Bubble rise through magma inside a volcanic conduit is effectively described by an appropriate flow regime, therefore eruptive dynamics can be studied in the framework of two-phase flow.
Nature Communications, 2021
The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur w... more The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur without obvious precursors. Modelling the source processes of these sudden blasts is challenging. Here, we use two decades of ground deformation (tilt) records from Stromboli volcano to shed light, with unprecedented detail, on the short-term (minute-scale) conduit processes that drive such violent volcanic eruptions. We find that explosive eruptions, with source parameters spanning seven orders of magnitude, all share a common pre-blast ground inflation trend. We explain this exponential inflation using a model in which pressure build-up is caused by the rapid expansion of volatile-rich magma rising from depth into a shallow (<400 m) resident magma conduit. We show that the duration and amplitude of this inflation trend scales with the eruption magnitude, indicating that the explosive dynamics obey the same (scale-invariant) conduit process. This scale-invariance of pre-explosion grou...
Journal of Volcanology and Geothermal Research, Aug 1, 1999
Journal of Volcanology and Geothermal Research, Jun 1, 2002
Journal of Volcanology and Geothermal Research, Jul 1, 1990
Bulletin of Volcanology, Apr 19, 2016
Bulletin of Volcanology, May 19, 2021
Oceanography, Mar 1, 2012
. In this paper we present a new model for the simulation of lahars, based on the depth-averaged ... more . In this paper we present a new model for the simulation of lahars, based on the depth-averaged code IMEX-SfloW2D with new governing and constitutive equations introduced to better describe the dynamics of lahars. A thorough sensitivity analysis is carried out to identify the critical processes (such as erosion and deposition) and parameters (both numerical and physical) controlling lahar runout, using both synthetic and real cases topographies. In particular, an application of the model to a syn-eruptive lahar from a reference-size eruption from Somma-Vesuvius, affecting the Campanian Plain (Southern Italy), described in Di Vito et al. (this issue), is used in this work for the sensitivity analysis. Effects of erosion and deposition are investigated by comparing simulations with and without these processes. By comparing flow thickness and area covered by the flow and their evolution with time, we show that the modelling of both the processes is important to properly simulate the effects of the bulking and debulking and the associated changes in rheology. From a computational point of view, the comparison of simulations obtained for different numerical grids (from 25 m to 100 m), scheme order, and grain size discretization were useful to find a good compromise between resolution and computational speed. The companion paper by Sandri et al. (this issue) shows an application of the presented model for probabilistic volcanic hazard assessment for lahars from Vesuvius deposits in the Neapolitan area.
Scientific Reports
The most frequent volcanic eruptions are of low-intensity and small magnitude. They produce abund... more The most frequent volcanic eruptions are of low-intensity and small magnitude. They produce abundant ash-sized (< 2 mm) clasts, which are too small to establish quantitative links between magmatic processes and eruptive dynamics using classic approaches. This inhibits our ability to study the past behaviour of frequently erupting volcanoes, essential to predict their future activity and mitigate their impact. The Palizzi unit (10–13th century, Vulcano, Italy) includes a prototype sequence of ash deposits resulting from prolonged Vulcanian eruptions punctuated by those of two larger sub-Plinian events. We apply Hierarchical Clustering to chemical analyses of clinopyroxene collected along the stratigraphy to decipher magma dynamics during this eruptive period. We identify periods of magma input and we link deep magmatic processes to eruptive dynamics, also showing that our approach can be used to connect magma and eruptive dynamics in any volcanic sequence. This is essential to tra...
Bulletin of Volcanology
In 1999–2001, Guagua Pichincha volcano, Ecuador, produced a series of cyclic explosive and effusi... more In 1999–2001, Guagua Pichincha volcano, Ecuador, produced a series of cyclic explosive and effusive eruptions. Rock samples, including dense blocks and pumiceous clasts collected during the eruption sequence, and ballistic bombs later collected from the crater floor, provide information about magma storage, ascent, decompression, degassing, repressurization, and regassing prior to eruption. Pairs of Fe-Ti oxides indicate equilibrium within 1.2–1.5 log units above the NNO oxidation buffer and equilibrium temperatures from 805 to 905 °C. Melt inclusions record H2O contents of 2.7–4.6 wt% and CO2 contents (uncorrected for CO2 segregation into bubbles) from 19 to 310 ppm. Minimum melt inclusion saturation pressures fall between 69 and 168 MPa, or equilibration depths of 2.8 and 6.8 km, the lower end of which is coincident with the maximum inferred equilibration depths for the most vesicular breadcrust bombs sampled. Amphibole phenocrysts lack breakdown rims (except for one sample) and p...
Geological Society, London, Special Publications
Volcanoes produce probably the most spectacular geological phenomena on Earth. Any of their erupt... more Volcanoes produce probably the most spectacular geological phenomena on Earth. Any of their eruptions can have a strong consequence on the surrounding environment, often captured in great detail in the sedimentary records of volcanically active regions. In addition, flank landslides and background erosive processes affecting volcanic sequences release volcanic particles that circulate within sedimentary environments up to billions of years after their generation. Therefore, exploring volcanically influenced sedimentary environments is an exciting and challenging scientific exercise requiring insights across multiple geological disciplines, drawing upon an increasing varied range of expertise and analytical approaches from across the geoscientific community. This book aims to provide an updated collection of works that illustrate the state-of-the-art in this topic, and to define the future directions of the geological sciences in utilizing and interpreting sedimentary records of volc...
Geological Society, London, Special Publications
This book brings together research, review and methodological papers that provide an updated view... more This book brings together research, review and methodological papers that provide an updated view on the sedimentary record of volcanism, spanning diverse processes and environments. It aims to bridge the gap between volcanological and sedimentological approaches to the investigation of processes governing the generation, dispersion and accumulation of volcaniclastic deposits.
Lahars are rapid flows composed of water and volcaniclastic sediments, which have the potential t... more Lahars are rapid flows composed of water and volcaniclastic sediments, which have the potential to impact residential buildings and critical infrastructure as well as to disrupt critical services, especially in absence of a hazard-based land-use planning. Their destructive power is mostly associated with their velocity (related to flow rheology and surrounding topography) and to their ability to bury buildings and structures (related to the deposit thickness). The distance reached by lahars depends on their volume, on sediments/water ratio, as well as on the overall characteristics of the path where they propagate. Here we present a novel strategy for the assessment of risk associated with lahar inundation related both to flow velocity and deposit thickness using Vulcano island (Italy) as a case study. First, a range of hazard scenarios has been identified that are related to the mobilization by intense rain events of tephra fallout deposited on the slopes of the La Fossa cone by a ...
Annals of Geophysics, 2021
T The paper addresses the long-lasting human presence on the island of Stromboli, an active vol... more T The paper addresses the long-lasting human presence on the island of Stromboli, an active volcano at the northern edge of the Aeolian archipelago, in the Southern Tyrrhenian sea, Italy. A conceptual model has been built to explore the phenomenon, it takes into account a series of aspects comparing Stromboli to other islands: their morphology, natural resources and geography along with the archaeological and historical data and, further, human attitude to volcanic environments, to risk and to insularity has been deeply explored. We propose a complex narrative where a combination of geological, socio-economic, historical, and psychological factors influenced people’s choices and that human presence is related more to the volcanic (and island) environment (and opportunities) than to volcanic activity.
Annals of Geophysics, 2021
In 79 A.D. Vesuvius buried entire cities in a few days under a blanket of pumice and ashes. It... more In 79 A.D. Vesuvius buried entire cities in a few days under a blanket of pumice and ashes. It was a sudden event, which occurred after centuries of inactivity, heralded only by earthquakes that repeated periodically, for many years, creating addiction rather than alarm. After the event, the vegetation covered the volcanic products, and the memory of the disaster was lost. The first excavations began in Herculaneum in 1738 and in Pompeii ten years later, in times when archeology still did not exist. Much was destroyed, given away, thrown away. Almost intact buildings emerged, with all their contents, with many inhabitants caught on the run. The arduous process of recovering the sites has had important and not always happy stages, accompanied by continuous progress in the excavation methods. Volcanology has drawn from those experiences as much as it could, setting itself the goal of reconstructing the story of an explosive eruption, the first in the world to be described, by Plin...
Annals of Geophysics, 2021
The lava platform and the three pyroclastic cones of Vulcanello constitute the northernmost vo... more The lava platform and the three pyroclastic cones of Vulcanello constitute the northernmost volcanic structure of the island of Vulcano (Aeolian Islands). The sandy isthmus connecting the platform to the main island was definitively formed in the first half of the 1500s; before then, Vulcano and Vulcanello were two close but separate islands. For a long time, the interpretation of the sources of the II-I century BC, had considered the islet as built up about 2200 years ago. This belief, which proliferated among naturalists from the 17th century, is not confirmed in the ancient texts or even in the geographical documents of the time, which do not indicate the presence of Vulcanello as a new and stable island near Vulcano. The islet would only be mentioned at the dawn of the second millennium, and named in Arabic “Gabal’ al Burkān”, meaning Mount of Vulcano; shortly thereafter the toponym changed to the Latin “Insulam Vulcanelli” and then, towards the 15th century, finally to Vulca...
Conclusions • System geometry controls rise velocity, which in turn controls break-up • There is ... more Conclusions • System geometry controls rise velocity, which in turn controls break-up • There is a specific size to the bubbles a system of a certain size and geometry can deliver • Being able to measure that size (through geophysical techniques) we can invert it to infer upper conduit geometry Bubble rise through magma inside a volcanic conduit is effectively described by an appropriate flow regime, therefore eruptive dynamics can be studied in the framework of two-phase flow.
Nature Communications, 2021
The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur w... more The mild activity of basaltic volcanoes is punctuated by violent explosive eruptions that occur without obvious precursors. Modelling the source processes of these sudden blasts is challenging. Here, we use two decades of ground deformation (tilt) records from Stromboli volcano to shed light, with unprecedented detail, on the short-term (minute-scale) conduit processes that drive such violent volcanic eruptions. We find that explosive eruptions, with source parameters spanning seven orders of magnitude, all share a common pre-blast ground inflation trend. We explain this exponential inflation using a model in which pressure build-up is caused by the rapid expansion of volatile-rich magma rising from depth into a shallow (<400 m) resident magma conduit. We show that the duration and amplitude of this inflation trend scales with the eruption magnitude, indicating that the explosive dynamics obey the same (scale-invariant) conduit process. This scale-invariance of pre-explosion grou...