scholarly journals Near-real-time volcanic cloud monitoring: insights into global explosive volcanic eruptive activity through analysis of Volcanic Ash Advisories

2021 ◽  
Vol 83 (2) ◽  
Author(s):  
S. Engwell ◽  
L. Mastin ◽  
A. Tupper ◽  
J. Kibler ◽  
P. Acethorp ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Activity ◽  
Volcanic Ash ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
Process Data ◽  
Cloud Monitoring ◽  
Satellite Sensors ◽  
Volcanic Cloud

AbstractUnderstanding the location, intensity, and likely duration of volcanic hazards is key to reducing risk from volcanic eruptions. Here, we use a novel near-real-time dataset comprising Volcanic Ash Advisories (VAAs) issued over 10 years to investigate global rates and durations of explosive volcanic activity. The VAAs were collected from the nine Volcanic Ash Advisory Centres (VAACs) worldwide. Information extracted allowed analysis of the frequency and type of explosive behaviour, including analysis of key eruption source parameters (ESPs) such as volcanic cloud height and duration. The results reflect changes in the VAA reporting process, data sources, and volcanic activity through time. The data show an increase in the number of VAAs issued since 2015 that cannot be directly correlated to an increase in volcanic activity. Instead, many represent increased observations, including improved capability to detect low- to mid-level volcanic clouds (FL101–FL200, 3–6 km asl), by higher temporal, spatial, and spectral resolution satellite sensors. Comparison of ESP data extracted from the VAAs with the Mastin et al. (J Volcanol Geotherm Res 186:10–21, 2009a) database shows that traditional assumptions used in the classification of volcanoes could be much simplified for operational use. The analysis highlights the VAA data as an exceptional resource documenting global volcanic activity on timescales that complement more widely used eruption datasets.

scholarly journals Volcanic ash modeling with the NMMB-MONARCH-ASH model: quantification of offline modeling errors

2018 ◽  
Vol 18 (6) ◽  
pp. 4019-4038 ◽  
Author(s):  
Alejandro Marti ◽  
Arnau Folch
Keyword(s):  
Volcanic Ash ◽  
Source Parameters ◽  
Atmospheric Dispersion ◽  
Volcanic Eruptions ◽  
Systematic Errors ◽  
Cloud Detection ◽  
Coupled Modeling ◽  
Evaluation Scores ◽  
Modeling Systems ◽  
Ash Cloud

Abstract. Volcanic ash modeling systems are used to simulate the atmospheric dispersion of volcanic ash and to generate forecasts that quantify the impacts from volcanic eruptions on infrastructures, air quality, aviation, and climate. The efficiency of response and mitigation actions is directly associated with the accuracy of the volcanic ash cloud detection and modeling systems. Operational forecasts build on offline coupled modeling systems in which meteorological variables are updated at the specified coupling intervals. Despite the concerns from other communities regarding the accuracy of this strategy, the quantification of the systematic errors and shortcomings associated with the offline modeling systems has received no attention. This paper employs the NMMB-MONARCH-ASH model to quantify these errors by employing different quantitative and categorical evaluation scores. The skills of the offline coupling strategy are compared against those from an online forecast considered to be the best estimate of the true outcome. Case studies are considered for a synthetic eruption with constant eruption source parameters and for two historical events, which suitably illustrate the severe aviation disruptive effects of European (2010 Eyjafjallajökull) and South American (2011 Cordón Caulle) volcanic eruptions. Evaluation scores indicate that systematic errors due to the offline modeling are of the same order of magnitude as those associated with the source term uncertainties. In particular, traditional offline forecasts employed in operational model setups can result in significant uncertainties, failing to reproduce, in the worst cases, up to 45–70 % of the ash cloud of an online forecast. These inconsistencies are anticipated to be even more relevant in scenarios in which the meteorological conditions change rapidly in time. The outcome of this paper encourages operational groups responsible for real-time advisories for aviation to consider employing computationally efficient online dispersal models.

scholarly journals Combination of SAR remote sensing and GIS for monitoring subglacial volcanic activity – recent results from Vatnajökull ice cap (Iceland)

2007 ◽  
Vol 7 (6) ◽  
pp. 717-722 ◽  
Author(s):  
K. Scharrer ◽  
R. Malservisi ◽  
Ch. Mayer ◽  
O. Spieler ◽  
U. Münzer
Keyword(s):  
Remote Sensing ◽  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
Remote Sensing And Gis ◽  
Envisat Asar ◽  
Ice Cap ◽  
Precise Prediction ◽  
Constant Potential ◽  
Active Vent

Abstract. This paper presents latest results from the combined use of SAR (Synthetic Aperture Radar) remote sensing and GIS providing detailed insights into recent volcanic activity under Vatnajökull ice cap (Iceland). Glaciers atop active volcanoes pose a constant potential danger to adjacent inhabited regions and infrastructure. Besides the usual volcanic hazards (lava flows, pyroclastic clouds, tephra falls, etc.), the volcano-ice interaction leads to enormous meltwater torrents (icelandic: jökulhlaup), devastating large areas in the surroundings of the affected glacier. The presented monitoring strategy addresses the three crucial questions: When will an eruption occur, where is the eruption site and which area is endangered by the accompanying jökulhlaup. Therefore, sufficient early-warning and hazard zonation for future subglacial volcanic eruptions becomes possible, as demonstrated for the Bardárbunga volcano under the northern parts of Vatnajökull. Seismic activity revealed unrest at the northern flanks of Bardárbunga caldera at the end of September 2006. The exact location of the corresponding active vent and therefore a potentially eruptive area could be detected by continuous ENVISAT-ASAR monitoring. With this knowledge a precise prediction of peri-glacial regions prone to a devastating outburst flood accompanying a possible future eruption is possible.

scholarly journals Sulphur dioxide as a volcanic ash proxy during the April–May 2010 eruption of Eyjafjallajökull Volcano, Iceland

2011 ◽  
Vol 11 (14) ◽  
pp. 6871-6880 ◽  
Author(s):  
H. E. Thomas ◽  
A. J. Prata
Keyword(s):  
Western Europe ◽  
Volcanic Ash ◽  
Final Phase ◽  
Middle Phase ◽  
Eruption Style ◽  
Infrared Imager ◽  
Cloud Monitoring ◽  
Volcanic Ash Cloud ◽  
Volcanic Cloud ◽  
Financial Losses

Abstract. The volcanic ash cloud from the eruption of Eyjafjallajökull volcano in April and May 2010 resulted in unprecedented disruption to air traffic in Western Europe causing significant financial losses and highlighting the importance of efficient volcanic cloud monitoring. The feasibility of using SO2 as a tracer for the ash released during the eruption is investigated here through comparison of ash retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) with SO2 measurements from a number of infrared and ultraviolet satellite-based sensors. Results demonstrate that the eruption can be divided into an initial ash-rich phase, a lower intensity middle phase and a final phase where considerably greater quantities both ash and SO2 were released. Comparisons of ash-SO2 dispersion indicate that despite frequent collocation of the two species, there are a number of instances throughout the eruption where separation is observed. This separation occurs vertically due to the more rapid settling rate of ash compared to SO2, horizontally through wind shear and temporally through volcanological controls on eruption style. The potential for the two species to be dispersed independently has consequences in terms of aircraft hazard mitigation and highlights the importance of monitoring both species concurrently.

scholarly journals Improving Ensemble Volcanic Ash Forecasts by Direct Insertion of Satellite Data and Ensemble Filtering

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1215
Author(s):  
Meelis J. Zidikheri ◽  
Chris Lucas
Keyword(s):  
Volcanic Ash ◽  
Weather Prediction ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Forecast Skill ◽  
Aviation Industry ◽  
Transport Modelling ◽  
Volcanic Source ◽  
Mass Load ◽  
Ensemble Filtering

Improved quantitative forecasts of volcanic ash are in great demand by the aviation industry to enable better risk management during disruptive volcanic eruption events. However, poor knowledge of volcanic source parameters and other dispersion and transport modelling uncertainties, such as those due to errors in numerical weather prediction fields, make this problem very challenging. Nonetheless, satellite-based algorithms that retrieve ash properties, such as mass load, effective radius, and cloud top height, combined with inverse modelling techniques, such as ensemble filtering, can significantly ameliorate these problems. The satellite-retrieved data can be used to better constrain the volcanic source parameters, but they can also be used to avoid the description of the volcanic source altogether by direct insertion into the forecasting model. In this study we investigate the utility of the direct insertion approach when employed within an ensemble filtering framework. Ensemble members are formed by initializing dispersion models with data from different timesteps, different values of cloud top height, thickness, and NWP ensemble members. This large ensemble is then filtered with respect to observations to produce a refined forecast. We apply this approach to 14 different eruption case studies in the tropical atmosphere. We demonstrate that the direct insertion of data improves model forecast skill, particularly when it is used in a hybrid ensemble in which some ensemble members are initialized from the volcanic source. Moreover, good forecast skill can be obtained even when detailed satellite retrievals are not available, which is frequently the case for volcanic eruptions in the tropics.

scholarly journals Sulphur dioxide as a volcanic ash proxy during the April–May 2010 eruption of Eyjafjallajökull Volcano, Iceland

2011 ◽  
Vol 11 (3) ◽  
pp. 7757-7780 ◽  
Author(s):  
H. E. Thomas ◽  
A. J. Prata
Keyword(s):  
Western Europe ◽  
Volcanic Ash ◽  
Final Phase ◽  
Lower Intensity ◽  
Middle Phase ◽  
Eruption Style ◽  
Infrared Imager ◽  
Cloud Monitoring ◽  
Volcanic Ash Cloud ◽  
Volcanic Cloud

Abstract. The volcanic ash cloud from the eruption of Eyjafjallajökull volcano in April and May 2010 resulted in unprecedented disruption to air traffic in Western Europe causing significant monetary loses and highlighting the importance of efficient volcanic cloud monitoring. The feasibility of using SO2 as a tracer for the ash released during the eruption is investigated here through comparison of ash retrievals from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) with SO2 measurements from a number of infrared and ultraviolet satellite-based sensors. Results demonstrate that the eruption can be divided into an initial ash-rich phase, a lower intensity middle phase and a final phase where considerably greater quantities of both ash and SO2 were released. Comparisons of ash-SO2 dispersion indicate that despite frequent collocation of the two species, there are a number of instances throughout the eruption where separation is observed. This separation occurs vertically due to the more rapid settling rate of ash compared to SO2, horizontally through wind shear and temporally through volcanological controls on eruption style. The potential for the two species to be dispersed independently has consequences in terms of aircraft hazard mitigation and highlights the importance of monitoring both species concurrently.

Banding and Volcanic Ash on Patagonian Glaciers

1957 ◽  
Vol 3 (21) ◽  
pp. 18-25 ◽  
Author(s):  
Louis Lliboutry
Keyword(s):  
Volcanic Activity ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Aerial Photographs

AbstractOn aerial photographs of the Patagonian ice fields several types of bands can be identified; (1) fine ogives similar to Lüder’s lines in metals; (2) dirt bands which are both the outcrop of the annual debris strata of the névé and melt borders (the Schmelzrände of von Klebelsberg); (3) annual wave ogives below some ice falls; (4) annual ogives in regenerated glaciers, the formation of which is studied; (5) large melt borders which occur at longer intervals as a result of volcanic eruptions. These latter give evidence on the volcanic activity in the middle of the Patagonian ice fields.

The 2019 July Stromboli volcano paroxysm event: contribution of infrasound to the Volcanic Ash Advisory Centers

2020 ◽  
Author(s):  
Emanuele Marchetti ◽  
Maurizio Ripepe ◽  
Alexis Le Pichon ◽  
Constantino Listowski ◽  
Lars Ceranna ◽  
...  
Keyword(s):  
Real Time ◽  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Volcano Monitoring ◽  
Pyroclastic Flows ◽  
Civil Aviation ◽  
Propagation Time ◽  
Stromboli Volcano ◽  
Eruptive Column ◽  
The Impact

<p>With the advent of civil aviation and growth in air traffic, the problem of volcanic ash encounter has become an issue of importance as a prompt response to volcanic eruptions is required to mitigate the impact of the volcanic hazard on aviation. Many volcanoes worldwide are poorly monitored, and most of the time notifications of volcanic eruptions are reported mainly based on satellite observations or visual observations. Among ground-based volcano monitoring techniques, infrasound is the only one capable of detecting explosive eruptions from distances of thousands of kilometers. On July 3 and August 28, 2019, two paroxysmal explosions occurred at Stromboli volcano. The events, that are similar in terms of energy and size to the peak explosive activity reported historically for the volcano, produced a significant emission of scoria, bombs and lapilli, that affected the whole island and fed an eruptive column that rose almost 5 km above the volcano. The collapse of the eruptive column also produced pyroclastic flows along the Sciara del Fuoco, a sector collapse on the northern flank of the volcano.</p><p>Being one of the best-monitored volcanoes of the world, the 2019 Stromboli paroxysmal explosions were observed in real-time and Civil Protection procedures started immediately. However, notification to the Toulouse Volcanic Ash Advisory Centre (VAAC) was not automated, and the VAA was issued only long after the event occurrence. The two explosions produced infrasound signals that were detected by several infrasound stations as far as Norway (IS37, 3380 km) and Azores islands (IS42, 3530 km). Despite of the latency due to the propagation time, infrasound-based notification arrays precedes the Volcanic Ash Advisories (VAAs) issued by Toulouse VACC. Following the same procedure applied for the Volcano Information System developed in the framework of the ARISE project, we show how infrasound array analysis could allow automatic, near-real-time identification of these eruptions with timely reliable source information. We highlight the need for an integration of the CTBT IMS infrasound network with local and regional infrasound arrays capable of providing a timely early warning to VAACs. This study opens new perspectives in volcano monitoring and could represent, in the future, an efficient tool in supporting VAACs activity.</p>

scholarly journals How will melting of ice affect volcanic hazards in the twenty-first century?

2010 ◽  
Vol 368 (1919) ◽  
pp. 2535-2558 ◽  
Author(s):  
Hugh Tuffen
Keyword(s):  
Climate Change ◽  
Volcanic Activity ◽  
Volcanic Eruptions ◽  
Volcanic Hazards ◽  
First Century ◽  
Last Deglaciation ◽  
Positive Feedbacks ◽  
Twenty First Century ◽  
Near Future ◽  
Critical Overview

Glaciers and ice sheets on many active volcanoes are rapidly receding. There is compelling evidence that melting of ice during the last deglaciation triggered a dramatic acceleration in volcanic activity. Will melting of ice this century, which is associated with climate change, similarly affect volcanic activity and associated hazards? This paper provides a critical overview of the evidence that current melting of ice will increase the frequency or size of hazardous volcanic eruptions. Many aspects of the link between ice recession and accelerated volcanic activity remain poorly understood. Key questions include how rapidly volcanic systems react to melting of ice, whether volcanoes are sensitive to small changes in ice thickness and how recession of ice affects the generation, storage and eruption of magma at stratovolcanoes. A greater frequency of collapse events at glaciated stratovolcanoes can be expected in the near future, and there is strong potential for positive feedbacks between melting of ice and enhanced volcanism. Nonetheless, much further research is required to remove current uncertainties about the implications of climate change for volcanic hazards in the twenty-first century.

scholarly journals Volcanic ash modeling with the NMMB-MONARCH-ASH model: quantification of off-line modeling errors

2017 ◽  
Author(s):  
Alejandro Marti ◽  
Arnau Folch
Keyword(s):  
Volcanic Ash ◽  
Source Parameters ◽  
Volcanic Eruptions ◽  
Systematic Errors ◽  
Cloud Detection ◽  
Coupled Modeling ◽  
Evaluation Scores ◽  
Modeling Systems ◽  
On Line ◽  
Ash Cloud

Abstract. Volcanic ash modeling systems are used to simulate the atmospheric dispersion of volcanic ash and to generate forecasts that quantify the impacts from volcanic eruptions on infrastructures, air quality, aviation, and climate. The efficiency of response and mitigation actions is directly associated to the accuracy of the volcanic ash cloud detection and modeling systems. Operational forecasts build on off-line coupled modeling systems where meteorological variables are updated at the specified coupling intervals. Despite the concerns from other communities regarding the accuracy of this strategy, the quantification of the systematic errors and shortcomings associated to the off-line modeling systems has received no attention. This paper employs the NMMB-MONARCH-ASH model to quantify these errors by employing different quantitative and categorical evaluation scores. The skills of the off-line coupling strategy are compared against those from an on-line forecast considered to be the best estimate of the true outcome. Case studies are considered for a synthetic eruption with constant eruption source parameters and for two historical events, which suitably illustrate the severe aviation disruptive effects of European (2010 Eyjafjallajökull) and South-American (2011 Cordón Caulle) volcanic eruptions. Evaluation scores indicate that systematic errors credited to off-line modeling are of the same order of magnitude that those associated to the source term uncertainties. In particular, traditional off-line forecasts employed in operational model setups can result in significant uncertainties, failing to reproduce, in the worst cases, up to 45–70 % of the ash cloud of an on-line forecast. These inconsistencies are anticipated to be even more relevant in scenarios where the meteorological conditions change rapidly in time. The outcome of this paper encourages operational groups responsible for real‐time advisories for aviation to consider employing computationally efficient on-line dispersal models.

scholarly journals Measurement Report: Lidar measurements of stratospheric aerosol following the Raikoke and Ulawun volcanic eruptions

2020 ◽  
Author(s):  
Geraint Vaughan ◽  
David Wareing ◽  
Hugo Ricketts
Keyword(s):  
Volcanic Ash ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Aerosol Layer ◽  
Raman Lidar ◽  
Lidar System ◽  
Elastic Channel ◽  
Lidar Measurements ◽  
Volcanic Cloud ◽  
Lidar Ratio

Abstract. On 22 June 2019 the Raikoke volcano in the Kuril islands erupted, sending a plume of ash and sulphur dioxide into the stratosphere. A Raman lidar system at Capel Dewi Atmospheric Observatory, UK (52.4° N, 4.1° W) has been used to measure the extent and optical depth of the stratospheric aerosol layer following the eruption. The elastic channel allowed measurements up to 25 km, but the Raman channel was only sensitive to the troposphere. Therefore, backscatter ratio profiles were derived by comparison with aerosol-free profiles derived from nearby radiosondes, corrected for aerosol extinction with a lidar ratio of 40–50 sr. Small amounts of aerosol were measured prior to the arrival of the volcanic cloud, probably from pyroconvection over Canada. Volcanic ash may have first arrived as a thin layer at 14 km late on 3 July, and was certainly detected from 13 July onwards, eventually extending up to 20.5 km. Aerosol optical depths reached around 0.05 by early August, decaying thereafter to around 0.01 by the end of 2019 and remaining around that level until May 2020. The location of peak backscatter varied considerably but was generally around 15 km. However, on one notable occasion on 25 August, a layer around 300 m thick with peak lidar backscatter ratio around 1.5 was observed as high as 21 km.

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