scholarly journals ANALYSIS OF DISPLACEMENTS OF THE LAVA FLOW SURFACE OF THE 2012–2013 TOLBACHIK FISSURE ERUPTION BY SAR INTERFEROMETRY

2020 ◽  
Keyword(s):  
Lava Flow ◽  
Fissure Eruption ◽  
Sar Interferometry ◽  
Flow Surface

Subsidence of the lava flow formed during 2012-2013 Tolbachik fissure eruption: SAR data and thermal model

2021 ◽  
Author(s):  
Valentin Mikhailov ◽  
Maria Volkova ◽  
Elena Timoshkina ◽  
Nikolay Shapiro ◽  
Vladimir Smirnov ◽  
...  
Keyword(s):  
Lava Flow ◽  
Thermal Model ◽  
Fissure Eruption ◽  
Lava Flows ◽  
Lava Field ◽  
The Real ◽  
Persistent Scatterers ◽  
Flow Surface ◽  
Science And Education ◽  
Maximum Subsidence

<p>During the Tolbachik fissure eruption which took place from November 27, 2012 to September 15, 2013 a lava flow of area about 45.8 km<sup>2</sup> and total lava volume ~0.6 km<sup>3</sup> was formed. We applied method of persistent scatterers to the satellite Sentinel-1A SAR images and estimated the rates of displacement of the lava field surface for 2017–2019. The surface mainly subsides along the satellite’s line-of-sight, with the exception of the periphery of the Toludski and Leningradski lava flows, where small uplifts are observed. Assuming that the displacements occur mainly along the vertical, the maximum average displacement rates for the snowless period of 2017–2019 were 285, 249, and 261 mm/year, respectively. On the Leningradski and Toludski lava flows the maximum subsidence was registered in areas with the maximum lava thickness.</p><p>To estimate the thermal subsidence of the lava surface we constructed a thermal model of lava cooling. It provides subsidence rate which are generally close to the real one over a significant part of the lava field, but in a number of areas of its central part, the real subsidence values are much higher than the thermal estimates. According to the thermal model when lava thickness exceeds 40 meters, even 5 years after eruption under the solidified surface there can be a hot, ductile layer, which temperature exceeds 2/3 of the melting one. Since on the Leningradski flow, the maximum subsidence is observed in the area of the fissure along which the eruption took place, one could assume that the retreat of lava down the fissure could contribute to the observed displacements of the flow surface. Subsidence can also be associated with compaction of rocks under the weight of the overlying strata. Migration of non-solidified lava under the solidified cover, also can contribute to the observed distribution of displacements - subsidence of the surface of the lava field in the upper part of the slope and a slight uplift at its periphery.</p><p>The work was supported partly by the mega-grant program of the Russian Federation Ministry of Science and Education under the project no. 14.W03.31.0033 and partly by the Interdisciplinary Scientific and Educational School of Moscow University «Fundamental and Applied Space Research».</p>

Geoheritage values of one of the largest maar craters in the Arabian Peninsula: the Al Wahbah Crater and other volcanoes (Harrat Kishb, Saudi Arabia)

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Mohammed Moufti ◽  
Károly Németh ◽  
Nabil El-Masry ◽  
Atef Qaddah
Keyword(s):  
Saudi Arabia ◽  
Lava Flow ◽  
Arabian Peninsula ◽  
Volcanic Hazards ◽  
Scoria Cone ◽  
Volcanic Field ◽  
Flow Surface ◽  
Geological Features ◽  
A Site ◽  
Tephra Ring

AbstractAl Wahbah Crater is one of the largest and deepest Quaternary maar craters in the Arabian Peninsula. It is NW-SE-elongated, ∼2.3 km wide, ∼250 m deep and surrounded by an irregular near-perpendicular crater wall cut deeply into the Proterozoic diorite basement. Very few scientific studies have been conducted on this unique site, especially in respect to understanding the associated volcanic eruption processes. Al Wahbah and adjacent large explosion craters are currently a research subject in an international project, Volcanic Risk in Saudi Arabia (VORiSA). The focus of VORiSA is to characterise the volcanic hazards and eruption mechanisms of the vast volcanic fields in Western Saudi Arabia, while also defining the unique volcanic features of this region for use in future geoconservation, geoeducation and geotourism projects. Al Wahbah is inferred to be a maar crater that formed due to an explosive interaction of magma and water. The crater is surrounded by a tephra ring that consists predominantly of base surge deposits accumulated over a pre-maar scoria cone and underlying multiple lava flow units. The tephra ring acted as an obstacle against younger lava flows that were diverted along the margin of the tephra ring creating unique lava flow surface textures that recorded inflation and deflation processes along the margin of the post-maar lava flow. Al Wahbah is a unique geological feature that is not only a dramatic landform but also a site that can promote our understanding of complex phreatomagmatic monogenetic volcanism. The complex geological features perfectly preserved at Al Wahbah makes this site as an excellent geotope and a potential centre of geoeducation programs that could lead to the establishment of a geopark in the broader area at the Kishb Volcanic Field.

scholarly journals Hazards from lava–river interactions during the 1783–1784 Laki fissure eruption

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2651-2668
Author(s):  
Frances Boreham ◽  
Katharine Cashman ◽  
Alison Rust
Keyword(s):  
Remote Sensing ◽  
Surface Water ◽  
Lava Flow ◽  
Field Studies ◽  
Fissure Eruption ◽  
Lava Flows ◽  
Aerial Photographs ◽  
Geological Evidence ◽  
Digital Terrain ◽  
Remote Mapping

Abstract Interactions between lava flows and surface water are not always considered in hazard assessments, despite abundant historical and geological evidence that they can create significant secondary hazards (e.g., floods and steam explosions). We combine contemporary accounts of the 1783–1784 Laki fissure eruption in southern Iceland with morphological analysis of the geological deposits to reconstruct the lava–water interactions and assess their impact on residents. We find that lava disrupted the local river systems, impounded water that flooded farms and impeded travel, and drove steam explosions that created at least 2979 rootless cones on the lava flow. Using aerial photographs and satellite-derived digital terrain models, we mapped and measured 12 of the 15 rootless cone groups on the Laki lava field. We have identified one new rootless cone group and provide data that suggest another cone group previously attributed to the 939–940 CE Eldgjá eruption was created by the Laki eruption. We then use contemporary accounts to estimate formation dates and environments for each cone group, which formed in wetland/lake areas, on riverbeds, and near areas of impounded water. Furthermore, comparison with previous field studies shows that assessments using remote sensing can be used to identify and map meter-scale and larger features on a lava flow, although remote mapping lacks the detail of field observations. Our findings highlight the different ways in which lava can interact with surface water, threatening people, property, water supplies, and infrastructure. For these reasons, anticipation of such interactions is important in lava flow hazard assessment in regions with abundant surface water; we further demonstrate that remote sensing can be an effective tool for identifying lava–water interactions in past lava flows.

Evidence of Fissure Eruption in the Tertiary Lava Plateau of North-East Ireland

1950 ◽  
Vol 87 (1) ◽  
pp. 45-52 ◽  
Author(s):  
E. M. Patterson
Keyword(s):  
Lava Flow ◽  
Fissure Eruption ◽  
Restricted Area ◽  
North East ◽  
Basalt Plateau ◽  
Relationship Of ◽  
Tertiary Basalt

AbstractAn example is described of a dyke feeding a lava flow in the Tertiary basalt plateau of North-East Ireland. The dyke has an erratic course and branches into several veinlets, but otherwise it displays the usual characters of a dyke. Continuity between dyke and flow is seen in five places in the restricted area of outcrop of the flow. The possible relationship of the dykes and volcanic plugs of Antrim to the plateau lavas is briefly discussed.

On the retrieval of lava-flow surface temperatures from infrared satellite data

Geology ◽  
2003 ◽  
Vol 31 (10) ◽  
pp. 893 ◽  
Author(s):  
Robert Wright ◽  
Luke P. Flynn
Keyword(s):  
Lava Flow ◽  
Satellite Data ◽  
Surface Temperatures ◽  
Flow Surface

scholarly journals The influence of slope breaks on lava flow surface disruption

2014 ◽  
Vol 119 (3) ◽  
pp. 1837-1850 ◽  
Author(s):  
Lori S. Glaze ◽  
Stephen M. Baloga ◽  
Sarah A. Fagents ◽  
Robert Wright
Keyword(s):  
Lava Flow ◽  
Flow Surface

Lava flow surface roughness and depolarized radar scattering

1996 ◽  
Vol 101 (E8) ◽  
pp. 18941-18951 ◽  
Author(s):  
Bruce A. Campbell ◽  
Michael K. Shepard
Keyword(s):  
Surface Roughness ◽  
Lava Flow ◽  
Flow Surface ◽  
Radar Scattering
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