A multi-sensor approach for volcanic ash cloud retrieval and eruption characterization: the 23 November 2013 Etna lava fountain

Volcanic activity is observed worldwide with a variety of ground and space-based remote sensing instruments, each with advantages and drawbacks. No single system can give a comprehensive description of eruptive activity, and so, a multi-sensor approach is required. This work integrates infrared and microwave volcanic ash retrievals obtained from the geostationary Meteosat Second Generation (MSG)-Spinning Enhanced Visible and Infrared Imager (SEVIRI), the polar-orbiting Aqua-MODIS and ground-based weather radar. The expected outcomes are improvements in satellite volcanic ash cloud retrieval (altitude, mass, aerosol optical depth and effective radius), the generation of new satellite products (ash concentration and particle number density in the thermal infrared) and better characterization of volcanic eruptions (plume altitude, total ash mass erupted and particle number density from thermal infrared to microwave). This approach is the core of the multi-platform volcanic ash cloud estimation procedure being developed within the European FP7-APhoRISM project. The Mt. Etna (Sicily, Italy) volcano lava fountaining event of 23 November 2013 was considered as a test case. The results of the integration show the presence of two volcanic cloud layers at different altitudes. The improvement of the volcanic ash cloud altitude leads to a mean difference between the SEVIRI ash mass estimations, before and after the integration, of about the 30%. Moreover, the percentage of the airborne “fine” ash retrieved from the satellite is estimated to be about 1%–2% of the total ash emitted during the eruption. Finally, all of the estimated parameters (volcanic ash cloud altitude, thickness and total mass) were also validated with ground-based visible camera measurements, HYSPLIT forward trajectories, Infrared Atmospheric Sounding Interferometer (IASI) satellite data and tephra deposits

Simulation Of The Volcanic Ash Dispersion During The June 2019 Sinabung Eruption

The eruption of Sinabung on June 9, 2019, was categorized as a red code in the warning report for flights. Volcanic ash from volcanic eruptions is a serious threat in the world of aviation with the most dangerous ash particles are 6-10 μm and 37 μm in diameter. To enrich our understanding and modeling performances of the volcanic ash dispersion for the Sinabung eruption case, it is necessary to simulate the dispersion of volcanic ash in those particular sizes to see its distribution which can impact flight routes. The method used was the analysis of the direction and dispersion of the particular volcanic ash using Weather Research Forecast-Chemistry (WRF-Chem) and compared it with the volcanic ash warning information on flight routes issued by Volcanic Ash Advisory Centers (VAAC)-Darwin. In general, WRF-Chem can simulate the distribution of volcanic ash from the eruption of Sinabung at the two-particle sizes at different heights, and found the difference in the distribution direction of the two groups of the particle sizes. Comparison results with warning information from VAAC-Darwin and previous study, WRF-Chem simulation shows a good concordance in the dispersion direction

The Use of Mt. Mazama Volcanic Ash as Natural Pozzolans for Sustainable Soil and Unpaved Road Improvement

Natural pozzolans can be a replacement for portland cement in many applications. Some natural pozzolans are byproducts of industrial processes. Other natural pozzolans, such as volcanic ash, occur naturally. This study determined the suitability of Mt. Mazama volcanic ash as a natural pozzolan and explored innovative uses of the material for roadway improvement. Requirements of natural pozzolans are specified in ASTM C618 – coal fly ash and raw or calcined natural pozzolan for use in concrete. This study concluded that volcanic ash from Mt. Mazama meets chemical requirements of a natural pozzolan. In its unprocessed, natural form, Mt. Mazama volcanic ash does not meet fineness, moisture or strength requirements as a natural pozzolan. An innovative study of the strength of mortar cubes created with increasing replacement of portland cement with Mt. Mazama volcanic ash showed that decreases in strength occur with increased percentage replacements. When the Mt. Mazama volcanic ash is crushed and passed through a No. 200 sieve, this decrease in strength is less than unprocessed material. Slurry mixes of Mt. Mazama volcanic ash, lime and portland cement applied to gravel materials bound material to a greater percentage, and reduced potentially airborne particulates to a greater degree than using portland cement slurry alone. A sustainability analysis concluded that any replacement of portland cement with volcanic ash reduces embodied energy and carbon dioxide emissions

The Use of Mt. Mazama Volcanic Ash as Natural Pozzolans for Sustainable Soil and Unpaved Road Improvement

Natural pozzolans can be a replacement for portland cement in many applications. Some natural pozzolans are byproducts of industrial processes. Other natural pozzolans, such as volcanic ash, occur naturally. This study determined the suitability of Mt. Mazama volcanic ash as a natural pozzolan and explored innovative uses of the material for roadway improvement. Requirements of natural pozzolans are specified in ASTM C618 – coal fly ash and raw or calcined natural pozzolan for use in concrete. This study concluded that volcanic ash from Mt. Mazama meets chemical requirements of a natural pozzolan. In its unprocessed, natural form, Mt. Mazama volcanic ash does not meet fineness, moisture or strength requirements as a natural pozzolan. An innovative study of the strength of mortar cubes created with increasing replacement of portland cement with Mt. Mazama volcanic ash showed that decreases in strength occur with increased percentage replacements. When the Mt. Mazama volcanic ash is crushed and passed through a No. 200 sieve, this decrease in strength is less than unprocessed material. Slurry mixes of Mt. Mazama volcanic ash, lime and portland cement applied to gravel materials bound material to a greater percentage, and reduced potentially airborne particulates to a greater degree than using portland cement slurry alone. A sustainability analysis concluded that any replacement of portland cement with volcanic ash reduces embodied energy and carbon dioxide emissions

Preparation and use of volcanic ash in concrete

During recent years, Kansas has produced over 90% of the volcanic ash produced in the United States. Other important areas of volcanic ash are to be found in California, Montana and Idaho. Extensive development of the latter named deposits awaits more advantageous markets than are now present --Origin of Volcanic Ash, page 2-3

Electrical charging of ash in Icelandic volcanic plumes

The existence of volcanic lightning and alteration of the atmospheric potential gradient in the vicinity of near-vent volcanic plumes provides strong evidence for the charging of volcanic ash. More subtle electrical effects are also visible in balloon soundings of distal volcanic plumes. Near the vent, some proposed charging mechanisms are fractoemission, triboelectrification, and the so-called "dirty thunderstorm" mechanism, which is where ash and convective clouds interact electrically to enhance charging. Distant from the vent, a self-charging mechanism, probably triboelectrification, has been suggested to explain the sustained low levels of charge observed on a distal plume. Recent research by Houghton et al. (2013) linked the self-charging of volcanic ash to the properties of the particle size distribution, observing that a highly polydisperse ash distribution would charge more effectively than a monodisperse one. Natural radioactivity in some volcanic ash could also contribute to self-charging of volcanic plumes. Here we present laboratory measurements of particle size distributions, triboelectrification and radioactivity in ash samples from the Gr\'{i}msv\"{o}tn and Eyjafjallaj\"{o}kull volcanic eruptions in 2011 and 2010 respectively, and discuss the implications of our findings.Comment: XV Conference on Atmospheric Electricity, 15-20 June 2014, Norman, Oklahoma, US