Living at the edge of an active volcano: Risk from lava flows on Mt. Etna

2019 ◽  
Vol 132 (7-8) ◽  
pp. 1615-1625 ◽  
Author(s):  
Ciro Del Negro ◽  
Annalisa Cappello ◽  
Giuseppe Bilotta ◽  
Gaetana Ganci ◽  
Alexis Hérault ◽  
...  
Keyword(s):  
Land Use ◽  
Lava Flow ◽  
Active Volcano ◽  
Lava Flows ◽  
Service Networks ◽  
Analytic Hierarchy ◽  
Thematic Layers ◽  
Exposed Population ◽  
Mt Etna ◽  
High Resolution Satellite Imagery

Abstract Lava flows represent the greatest threat by far to exposed population and infrastructure on Mt. Etna, Italy. The increasing exposure of a larger population, which has almost tripled in the area around Mt. Etna during the past 150 years, has resulted from poor assessment of the volcanic hazard and inappropriate land use in vulnerable areas. Here we quantify the lava flow risk on the flanks of Mt. Etna volcano using a Geographic Information System (GIS)-based approach that integrates the hazard with the exposure of elements at stake. The hazard, which shows the long-term probability related to lava flow inundation, is obtained by combining three different kinds of information: the spatiotemporal probability of new flank eruptive vents opening in the future, the event probability associated with classes of expected eruptions, and the overlapping of lava flow paths simulated by the MAGFLOW model. Data including all exposed elements were gathered from institutional web portals and high-resolution satellite imagery and organized in four thematic layers: population, buildings, service networks, and land use. The total exposure is given by a weighted linear combination of the four thematic layers, where weights are calculated using the Analytic Hierarchy Process (AHP). The resulting risk map shows the likely damage caused by a lava flow eruption and allows rapid visualization of the areas subject to the greatest losses if a flank eruption were to occur on Mt. Etna. The highest risk is found in the southeastern flank due to the combination of high hazard and population density.

Lava flow risk assessment on Mount Etna through hazard and exposure modelling

2020 ◽  
Author(s):  
Annalisa Cappello ◽  
Giuseppe Bilotta ◽  
Claudia Corradino ◽  
Gaetana Ganci ◽  
Alexis Hérault ◽  
...  
Keyword(s):  
Land Use ◽  
Lava Flow ◽  
Mount Etna ◽  
Service Networks ◽  
Analytic Hierarchy ◽  
Flow Paths ◽  
Thematic Layers ◽  
Exposed Population ◽  
Mt Etna ◽  
High Resolution Satellite Imagery

<p>Lava flows represent the greatest threat to exposed population and infrastructure on Mt Etna volcano (Italy). The increasing exposure of a larger population, which has almost tripled in the area around Mt Etna during the last 150 years, has resulted from poor assessment of the volcanic hazard, allowing inappropriate land use in vulnerable areas. We present a new methodology to quantify the lava flow risk on Etna’s flanks using a GIS-based approach that integrates the hazard with the exposure of elements at stake. The hazard, showing the long-term probability related to lava flow inundation, is obtained by combining three different kinds of information: the spatiotemporal probability of the future opening of new flank eruptive vents, the event probability associated with classes of expected eruptions, and the overlapping of lava flow paths simulated by the MAGFLOW model. Data including all exposed elements have been gathered from institutional web portals and high-resolution satellite imagery, and organized in four thematic layers: population, buildings, service networks, and land use. The total exposure is given by a weighted linear combination of the four thematic layers, where weights are calculated using the Analytic Hierarchy Process (AHP). The resulting risk map shows the likely damage caused by a lava flow eruption, allowing rapid visualization of the areas subject to the greatest losses if a flank eruption were to occur on Etna.</p>

The eccentric cones Monte De Fiore, Monti Rossi, Monte Spagnolo and the 2002/2003 eruption, Mt. Etna: evidence for magma mixing

2020 ◽  
Author(s):  
Moritz Bauer ◽  
Theodoros Ntaflos ◽  
Rainer Abart ◽  
Pier-Paolo Giacomoni ◽  
Carmelo Ferlito ◽  
...  
Keyword(s):  
Lava Flow ◽  
Melt Inclusions ◽  
Magma Mixing ◽  
Active Volcano ◽  
Mineral Chemistry ◽  
Geodynamic Setting ◽  
Plumbing System ◽  
Rock Composition ◽  
Mt Etna ◽  
Normal Zoning

<p>Mt. Etna is one of the most protrusive features of the eastern coastline of Sicily, Italy. As Europe’s most active volcano it has been studied extensively to reveal its geodynamic setting, plumbing system and due to the constant monitoring of the volcano edifice the prediction of the risk future events is sophisticated at Mt. Etna.</p><p>The eruptive activity has been divided according to the age into 6 stages: (1) “Tholeiitic Stage”, was active between 600-320 ka ago, (2) the “Timpe Stage” between 220 and 110 ka ago, (3) the “Ancient Alcaline Volcanism”  between 110 and 65 ka ago and (4) the “Ellittico Stage” between 57 and 15 ka ago (5) the “Mongibello Stage” from 15 ka ago until 1971 and (6) the “post -1971 Stage” active since 1971 (Casetta et al., 2019).</p><p>The lava propagating through the Etnean plumbing system generated a complex network consisting of sills and dykes responsible for the formation of the summit craters and a plethora of eccentric cones that cover the flanks of the volcano.</p><p>We studied whole rock and mineral chemistry of the lavas from three eccentric cones (Monte Spagnolo, Monte Fiori and Monte Rossi) and the 2002/2003 southern flank lava flow. All lavas are characterized by trachytic texture with variable modal composition of olivine, clinopyroxene and plagioclase phenocrysts. Euhedral and skeletal olivine phenocrysts can be distinguished into three main groups; a) normal zoning, b) inverse zoning, and c) patchy appearance with melt inclusions of andesitic and trachytic composition. The Monte Spagnolo whole rock composition has an Mg# ranging between 52-54 and 10.7 wt% CaO , being are the most primitive lavas among the sampled outcrops whereas the Monte De Fiore lavas are the most evolved since the Mg# ranges from 48.6 to 49.2 and the CaO content from 11 to 11.2 wt%. Both, Monti Rossi and the  2002/2003 lava flow are more evolved than the Monte Spagnolo since they have Mg# ~ 50 and 49-49.3 respectively. The CaO concentration in both outcrops is relatively constant ranging around 10.5 wt%.</p><p>The olivine compositions follow the same trend as their whole rocks. The most MgO-rich olivine (Fo=88.9 %) was found in the Monte Spagnolo lavas. This olivine is of magmatic origin and cannot be considered as mantle derived xenocryst since the NiO content is low (NiO=0.17 – 0.2 wt%) and the CaO-content high (CaO=0.24 – 0.26 wt%). The most evolved lavas from Monte De Fiore have the lowest Fo-content (Fo=75 - 78 %). Olivine from all samples has a characteristic inverse zonation with, at Monti Rossi and 2002/2003 lava flow, Fo-content in the core ranging from 69% to 75% and in the rim from 77% to 80% respectively.</p><p>In conclusion, the studied eccentric cones show extensive magma mixing as can be inferred from the olivine inverse zoning. Monte Spagnolo lavas represent the most primitive magma formed at high temperatures (olivine skeletal growing) and the Monte De Fiore lavas the most evolved magma.</p><p> </p><p>Casetta et al., 2019. International Geology Review, DOI: 10.1080/00206814.2019.1610979</p>

scholarly journals Recent eruption history inferred from eruption ages of the two latest lava flows using multi-dating at Yokodake Volcano, Japan

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Hiroya Nitta ◽  
Takeshi Saito ◽  
Yorinao Shitaoka
Keyword(s):  
Lava Flow ◽  
Volcanic Activity ◽  
Active Volcano ◽  
Lava Flows ◽  
Eruption Rate ◽  
Dating Methods ◽  
Paleomagnetic Dating ◽  
History Of ◽  
Eruption History ◽  
Recent Eruption

Abstract Reconstruction of the eruption history of an active volcano is necessary to elucidate its volcanic activity and to assess the probability of its volcanic eruption. Yokodake volcano in central Japan is the only active volcano among the Yatsugatake volcano group. It has effused nine lava flows, most of which have not been dated. For this study, we ascertained the eruption ages of the latest lava (Y9) and second most recent lava (Y8) using radiocarbon (14C), thermoluminescence (TL), and paleomagnetic dating methods. Results revealed the eruption ages of the two lava flows and the recent eruption history of Yokodake volcano. Yokodake volcano effused its Y8 lava flow at ca. 3.4 ka, ejected NYk-2 tephra with explosive eruption at ca. 2.4–2.2 ka, and effused the Y9 lava flow associated with Y9-T tephra at ca. 0.6 ka. Magma eruption rates of Yokodake at 34 ky and 3.4 ky were estimated as about 9 × 10−3 km3/ky and 1 × 10−2 km3/ky, indicating a stable eruption rate maintained during the past 34 ky. This result suggests that Yokodake volcano retains some potential for eruption, although the volcanic activity of the Yatsugatake volcanoes (10−1–10−2 km3/ky) has weakened over time.

scholarly journals The Estimation of Lava Flow Temperatures Using Landsat Night-Time Images: Case Studies from Eruptions of Mt. Etna and Stromboli (Sicily, Italy), Kīlauea (Hawaii Island), and Eyjafjallajökull and Holuhraun (Iceland)

2020 ◽  
Vol 12 (16) ◽  
pp. 2537 ◽  
Author(s):  
Ádám Nádudvari ◽  
Anna Abramowicz ◽  
Rosanna Maniscalco ◽  
Marco Viccaro
Keyword(s):  
Lava Flow ◽  
Volcanic Eruptions ◽  
Radiant Heat ◽  
Heat Fluxes ◽  
Lava Flows ◽  
Spectral Radiance ◽  
Night Time ◽  
Blue Band ◽  
Hawaii Island ◽  
Mt Etna

Using satellite-based remote sensing to investigate volcanic eruptions is a common approach for preliminary research, chiefly because a great amount of freely available data can be effectively accessed. Here, Landsat 4-5TM, 7ETM+, and 8OLI night-time satellite images are used to estimate lava flow temperatures and radiation heat fluxes from selected volcanic eruptions worldwide. After retrieving the spectral radiance, the pixel values were transformed into temperatures using the calculated calibration constants. Results showed that the TIR and SWIR bands were saturated and unable to detect temperatures over the active lava flows. However, temperatures were effectively detected over the active lava flows in the range ~500–1060 °C applying the NIR-, red-, green- or blue-band. Application of the panchromatic band with 15 m resolution also revealed details of lava flow morphology. The calculated radiant heat flux for the lava flows accords with increasing cooling either with slope or with distance from the vent.

scholarly journals Rheological and morphological evolution of basaltic lava flows

2018 ◽  
Author(s):  
◽  
Arianna Soldati
Keyword(s):  
Lava Flow ◽  
Flow Structure ◽  
Flow System ◽  
Morphological Evolution ◽  
Human Life ◽  
Active Volcano ◽  
Flow Dynamics ◽  
Lava Flows ◽  
System Structure ◽  
Basaltic Lava

Over 500 million people live in proximity of an active volcano globally. Although lava flows rarely endanger human life, they often destroy critical infrastructure. Advancing our understanding of lava flow dynamics is therefore critical to developing accurate hazard assessment, with key socio-economic impacts for many communities. This work focuses on basaltic lava rheology, which exerts a first-order control on flow dynamics and is reflected in lava morphology. In particular, I address the following research questions: (1) How does the rheology of active flows evolve during emplacement; and (2) How can we use flow morphology to infer the rheology of inactive flows? ... At Piton de La Fournaise (La R�union, FR DOM), I addressed the longstanding question of how pre-existing topography controls lava flow system structure in volume-limited flows (Soldati et al., accepted). I concluded that a steep slope results in a single, stable channel, whereas a gentle slope results in an unstable, braided channel. The findings of this study allow us to interpret and explain the observed flow structure on the basis of pre-existing volcano topography, and to forecast future flow structure. This allowed me to determine that rheology neither affects nor is affected by flow system configuration.

scholarly journals Anatomy of a Paroxysmal Lava Fountain at Etna Volcano: The Case of the 12 March 2021, Episode

2021 ◽  
Vol 13 (15) ◽  
pp. 3052
Author(s):  
Sonia Calvari ◽  
Alessandro Bonaccorso ◽  
Gaetana Ganci
Keyword(s):  
Lava Flow ◽  
Ground Deformation ◽  
Monitoring Network ◽  
Lava Flows ◽  
Etna Volcano ◽  
Lava Fountain ◽  
Eruptive Episode ◽  
Lava Fountains ◽  
Borehole Strainmeter ◽  
Ash Plume

On 13 December 2020, Etna volcano entered a new eruptive phase, giving rise to a number of paroxysmal episodes involving increased Strombolian activity from the summit craters, lava fountains feeding several-km high eruptive columns and ash plumes, as well as lava flows. As of 2 August 2021, 57 such episodes have occurred in 2021, all of them from the New Southeast Crater (NSEC). Each paroxysmal episode lasted a few hours and was sometimes preceded (but more often followed) by lava flow output from the crater rim lasting a few hours. In this paper, we use remote sensing data from the ground and satellite, integrated with ground deformation data recorded by a high precision borehole strainmeter to characterize the 12 March 2021 eruptive episode, which was one of the most powerful (and best recorded) among that occurred since 13 December 2020. We describe the formation and growth of the lava fountains, and the way they feed the eruptive column and the ash plume, using data gathered from the INGV visible and thermal camera monitoring network, compared with satellite images. We show the growth of the lava flow field associated with the explosive phase obtained from a fixed thermal monitoring camera. We estimate the erupted volume of pyroclasts from the heights of the lava fountains measured by the cameras, and the erupted lava flow volume from the satellite-derived radiant heat flux. We compare all erupted volumes (pyroclasts plus lava flows) with the total erupted volume inferred from the volcano deflation recorded by the borehole strainmeter, obtaining a total erupted volume of ~3 × 106 m3 of magma constrained by the strainmeter. This volume comprises ~1.6 × 106 m3 of pyroclasts erupted during the lava fountain and 2.4 × 106 m3 of lava flow, with ~30% of the erupted pyroclasts being remobilized as rootless lava to feed the lava flows. The episode lasted 130 min and resulted in an eruption rate of ~385 m3 s−1 and caused the formation of an ash plume rising from the margins of the lava fountain that rose up to 12.6 km a.s.l. in ~1 h. The maximum elevation of the ash plume was well constrained by an empirical formula that can be used for prompt hazard assessment.

On Composite Lava Flows.

1931 ◽  
Vol 68 (4) ◽  
pp. 166-181 ◽  
Author(s):  
W. Q. Kennedy
Keyword(s):  
Lava Flow ◽  
Lava Flows ◽  
The Other ◽  
Geological Survey ◽  
Main Subject ◽  
Lower Carboniferous ◽  
Fluid State ◽  
Mutual Contact ◽  
The World ◽  
Probable Effect

For many years composite minor intrusions, both sills and dykes, have been known from various parts of the world and most petrologists must have speculated as to the probable effect produced in the event of such composite intrusions having reached the surface in the form of an effusion. For obvious reasons it has not been found possible to trace a composite dyke upwards into a lava flow. However, during the revision of 1 inch Sheet 30 (Renfrewshire) for the Geological Survey, the author encountered, in the neighbourhood of Inverkip, a small village on the Firth of Clyde south of Greenock, certain peculiar lava flows which are believed to represent the effusive equivalents of composite minor intrusions. These “composite lavas”, which form the main subject of the present paper, are of Lower Carboniferous age (Calciferous Sandstone Series) and occur interbedded among the more normal flows towards the base of the volcanic group. Two distinct rock varieties, one highly porphyritic, with large phenocrysts (up to 1·5 cms. long) of basic plagioclase, and the other non-porphyritic, are associated within the same flow. The porphyritic type always forms the upper part of the flow and overlies the non-porphyritic; the junction shows unmistakable evidence that both were in a fluid state along their mutual contact at the time of emplacement.

Spatial distribution of soil radon as a tool to recognize active faulting on an active volcano: the example of Mt. Etna (Italy)

2011 ◽  
Vol 102 (9) ◽  
pp. 863-870 ◽  
Author(s):  
Marco Neri ◽  
Salvatore Giammanco ◽  
Elisabetta Ferrera ◽  
Giuseppe Patanè ◽  
Vittorio Zanon
Keyword(s):  
Spatial Distribution ◽  
Active Volcano ◽  
Active Faulting ◽  
Soil Radon ◽  
Mt Etna

scholarly journals Study of Road Landscape Design at Portal Space of Small Towns in Guanzhong#

2015 ◽  
Vol 9 (1) ◽  
pp. 92-98 ◽  
Author(s):  
Quanhua Hou ◽  
Wenhui Wang
Keyword(s):  
Land Use ◽  
Public Service ◽  
Influence Factors ◽  
Small Towns ◽  
Land Use Intensity ◽  
Analytic Hierarchy ◽  
Intensity Index ◽  
Influence Mechanism ◽  
Different Characteristics

To further study the effects of public service facilities on the land use intensity at regulatory planning level and enhance the scientific determination of land use intensity, this paper expounds the influence mechanism and factors of the public service facilities on land use intensity in regulatory planning, and conducts quantitative evaluation of the influence factors through theoretical analysis, mathematical analysis and analytic hierarchy process etc. The results show that the influence mechanism of public service facilities on the land use intensity goes throughout all three levels of regulatory planning. Different characteristics of public service facilities on each level determine their different influence factors and take effect on the land use intensity index of the corresponding level, thus affecting the determination of the block floor area ratio. Based on this, this paper proposes a method to determine the land use intensity in regulatory planning under the restriction of public service facilities and completes the test in practice, which may provide a reference for determining the land use intensity in regulatory planning.

scholarly journals Sensibility analysis of VORIS lava-flow simulations: application to Nyamulagira volcano, Democratic Republic of Congo

2015 ◽  
Vol 3 (3) ◽  
pp. 1835-1860
Author(s):  
A. M. Syavulisembo ◽  
H.-B. Havenith ◽  
B. Smets ◽  
N. d'Oreye ◽  
J. Marti
Keyword(s):  
Lava Flow ◽  
Democratic Republic ◽  
Democratic Republic Of Congo ◽  
Lava Flows ◽  
Past Century ◽  
Republic Of Congo ◽  
Political Issues ◽  
Aster Gdem ◽  
Volcano Observatory ◽  
Digital Elevation

Abstract. Assessment and management of volcanic risk are important scientific, economic, and political issues, especially in densely populated areas threatened by volcanoes. The Virunga area in the Democratic Republic of Congo, with over 1 million inhabitants, has to cope permanently with the threat posed by the active Nyamulagira and Nyiragongo volcanoes. During the past century, Nyamulagira erupted at intervals of 1–4 years – mostly in the form of lava flows – at least 30 times. Its summit and flank eruptions lasted for periods of a few days up to more than two years, and produced lava flows sometimes reaching distances of over 20 km from the volcano, thereby affecting very large areas and having a serious impact on the region of Virunga. In order to identify a useful tool for lava flow hazard assessment at the Goma Volcano Observatory (GVO), we tested VORIS 2.0.1 (Felpeto et al., 2007), a freely available software (http://www.gvb-csic.es) based on a probabilistic model that considers topography as the main parameter controlling lava flow propagation. We tested different Digital Elevation Models (DEM) – SRTM1, SRTM3, and ASTER GDEM – to analyze the sensibility of the input parameters of VORIS 2.0.1 in simulation of recent historical lava-flow for which the pre-eruption topography is known. The results obtained show that VORIS 2.0.1 is a quick, easy-to-use tool for simulating lava-flow eruptions and replicates to a high degree of accuracy the eruptions tested. In practice, these results will be used by GVO to calibrate VORIS model for lava flow path forecasting during new eruptions, hence contributing to a better volcanic crisis management.

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