Ana Silvia Casas

Australian National University | ANU · Research School of Physics & Engineering

The viscosity of molten Earth mantle has been determined for various redox states using very high temperature viscometry at 1 bar. The viscosity-temperature relationship of the most oxidised pyrolite studied here is comparable to that of a previous determination of the viscosity of a peridotite melt. For the first time, the effect of iron redox sta...

Formation of soluble sulfate and halide salts on volcanic ash particles via syn-eruptive interactions between ash surfaces and magmatic gases is a ubiquitous phenomenon in explosive eruptions. Surficial salts may be rapidly mobilized into their depositional environment undermining the quality of drinking water, harming aquatic life, and damaging so...

V25A-0087 Formation of surficial sulfate– and halide–bearing salts by syn–eruptive ash–gas interactions is known to occur during volcanic eruptions. For reactions between aluminosilicates and the gas SO2, at high temperature regimes (T≥ 600 °C), the controlling mechanism is the outward chemical diffusion of alkalis and alkaline earth metals, predom...

10.2138/am-2021-7691

Volcanic ash can trigger ice nucleation when immersed in supercooled water. This will impact several processes (e.g., electrification, aggregation, precipitation) in the eruption plume and cloud and in the wider atmosphere upon ash dispersal. Previous studies show that ash bulk properties, reflecting the chemistry and phase state of the source magm...

Glass-SO₂ reactions occurring at high temperatures in (terrestrial and extraterrestrial) volcanic environments have received increasing attention in the past years (e.g., Renggli and King 2018; Casas et al. 2019; Renggli et al. 2019), based on both natural and experimental observations. Laboratory studies carried out at high temperatures (>200°C) d...

Hot volcanic gases released during large volcanic eruptions can be removed from the atmosphere (i.e. gas scavenging), due to high-temperature adsorption and subsequent crystal growth on the surface of glassy ash particles. This has been shown to be a feasible mechanism in hot volcanic plumes and in conduits above the fragmentation front. However, t...

Volcanic plumes are complex environments composed of gases and ash particles, where chemical and physical processes occur at different temperature and compositional regimes. Commonly, soluble sulphate- and chloride-bearing salts are formed on ash as gases interact with ash surfaces. Exposure to respirable volcanic ash following an eruption is poten...

We investigate high-temperature SO 2 scavenging by natural calc-alkaline rhyolite particles. We simulate this process experimentally, by reacting powdered rhyolite glass particles of a range of grainsize distributions with SO 2 atmospheres at high temperature for various exposure times. The gas phase is either hydrous (SO 2-H 2 O) or anhydrous (SO...

Accurate estimates of the atmospheric impacts of large eruptions on the environment are complicated by a paucity of models for gas-magma or gas-rock interactions that can occur in the subsurface. It is in these environments that high-temperature scavenging of magmatic gases, released during eruptions, may play a major role, resulting in significant...

https://ui.adsabs.harvard.edu/abs/2018AGUFMGH13B0942T/abstract

Accurate predictions of volcanological phenomena, such as the trajectory of blocks accelerated by volcanic explosions, require quantitative skills training. Large outdoor experiments can be useful to convey concepts of volcanic processes to students in an exciting way. Beyond the fun aspects, these experiments provide an opportunity to engage with...

ABSTRACTS VOLUME OF THE INTERNATIONAL MEETING “CITIES ON VOLCANOES 10”, MILLENIA OF STRATIFICATION BETWEEN HUMAN LIFE AND VOLCANOES: STRATEGIES FOR COEXISTENCE. Editors: Rosa Anna Corsaro, Maria Giulia Di Giuseppe, Roberto Isaia, Angela Mormone, Rosella Nave. Publisher: INGV Istituto Nazionale di Geofisica e Vulcanologia, Italy. Pages: 1126-1126. I...

Hot volcanic gases can be removed from the atmosphere (i.e. gas scavenging), due to adsorption and subsequent crystal growth on glassy ash particles. This has been shown to be a feasible mechanism in hot volcanic plumes and in conduits above the fragmentation front. However, the possibility of scavenging occurring during outgassing through permeabl...

The aim of our study is to gain a first understanding of the effects of salt-laden ash particles (produced through simulated high-temperature in-plume processing) on respiratory health, using a 3D human lung model in vitro.

Although many studies have investigated the occurrence of gas scavenging (by ash particles) during large volcanic eruptions, the mechanisms involved in these processes are not completely understood. Our work seeks to constrain the particle properties that lead to gas adsorption onto ash surfaces, through a combined experimental and modelling approa...

Interactions with volcanic gases in eruption plumes produce soluble salt deposits on the surface of volcanic ash. While it has been postulated that saturation-driven precipitation of salts following the dissolution of ash surfaces by condensed acidic liquids is a primary mechanism of salt formation during an eruption, it is only recently that this...

In the course of explosive volcanic eruptions, large amounts of ash are released into the atmosphere and may subsequently pose a threat to infrastructure, such as aviation industry. Ash plume forecasting is therefore a crucial tool for volcanic hazard mitigation but may be significantly affected by aggregation, altering the aerodynamic properties o...

In-plume gas scavenging-processes are well known to occur in large volcanic eruptions, where, over the range of plume conditions (temperature and gas composition) and physicochemical ash-surface properties, volcanic gases (mainly SO 2 , HCl, and HF) can be sequestrated by the occurrence (alone or combined) of three processes: (1) salt deposition, (...

Monitoring of El Chichón volcanic activity is a very important given its eruption of March 28th, 1982 that was the worst volcanic disaster of the modern era in Mexico. To help mitigation of volcanic risk, we intend the establishment of an analytical methodology for the determining various sulfur species (S2-, SO 3 2-, S4O6 2-, SO4 2-) occurring in...

El monitoreo geoquímico del volcán Chichón, localizado al suroeste del Estado de Chiapas, representa una actividad de suma importancia dados los antecedentes eruptivos del mismo; la erupción del 28 de Marzo de 1982 fue el peor desastre volcánico de la era moderna en México. Para contribuir a la mitigación del riesgo volcánico se plantea el establec...