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    Prototype PBO instrumentation of CALIPSO project captures world‐record lava dome collapse on Montserrat Volcano
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    Abstract:
    This article is an update on the status of an innovative new project designed to enhance generally our understanding of andesitic volcano eruption dynamics and, specifically the monitoring and scientific infrastructure at the active Soufrière Hills Volcano (SHV), Montserrat. The project has been designated as the Caribbean Andesite Lava Island Precision Seismo‐geodetic Observatory known as CALIPSO. Its purpose is to investigate the dynamics of the entire SHV magmatic system using an integrated array of specialized instruments in four strategically located ∼200‐m‐deep boreholes in concert with several shallower holes and surface sites. The project is unique, as it represents the first, and only such borehole volcano‐monitoring array deployed at an andesitic stratovolcano.
    Keywords:
    Stratovolcano
    Lava dome
    The structures and textures preserved in lava domes reflect underlying magmatic and eruptive processes, and may provide evidence of how eruptions initiate and evolve. This study explores the remarkable cycles in lava extrusion style produced between 1922 and 2012 at the Santiaguito lava dome complex, Guatemala. By combining an examination of eruptive lava morphologies and textures with a review of historical records, we aim to constrain the processes responsible for the range of erupted lava type and morphologies. The Santiaguito lava dome complex is divided into four domes (El Caliente, La Mitad, El Monje, El Brujo), containing a range of proximal structures (e.g. spines) from which a series of structurally contrasting lava flows originate. Vesicular lava flows (with a'a like, yet non-brecciated flow top) have the highest porosity with interconnected spheroidal pores and may transition into blocky lava flows. Blocky lava flows are high volume and texturally variable with dense zones of small tubular aligned pore networks and more porous zones of spheroidal shaped pores. Spines are dense and low volume and contain small skeletal shaped pores, and subvertical zones of sigmoidal pores. We attribute the observed differences in pore shapes to reflect shallow inflation, deflation, flattening or shearing of the pore fraction. Effusion rate and duration of the eruption define the amount of time available for heating or cooling, degassing and outgassing prior to and during extrusion, driving changes in pore textures and lava type. Our new textural data when reviewed with all the other published data allows cyclic models to be developed. The cyclic eruption models are influenced by viscosity changes resulting from (1) initial magmatic composition and temperature, and (2) effusion rate which in turn affects degassing, outgassing and cooling time in the conduit. Each lava type presents a unique set of hazards and understanding the morphologies and dome progression is useful in hazard forecasting.
    Lava dome
    Lava field
    Effusive eruption
    Shield volcano
    Dome (geology)
    Citations (42)
    The potential of Mount Ireng is not only a beautiful romance on the face of the earth, butalso the geological peculiarity of the facies of ancient volcanic centers based on the volcanic and volcanic rocks spread over 7 (seven) clusters in the form of andesitic blocky lava, andesitic lava, massive andesitic lava and basaltic andesite lava cushions scattered in 7 (seven) clusters in the form of blocky andesitic lava, andesitic lava, massive andesitic lava and basaltic andesite lava cushions spread over 7 (seven) clusters in the form of blocky andesitic lava, andesitic lava lava, massive andesitic lava andesite dike with the presence of pyrite and sulfur minerals which are carried by andesitic breccias and agglomerates, besides being supported by tourism potential as the location of the best sunrise in Yogyakarta. This became the foundation taken by the Gunung Ireng Geotourism Academic Advisory Team from IST AKPRIND Yogyakarta in the form of submission of Mount Ireng to a Geological Nature Reserve (KCAG) in order to increase the development of sustainable community-based geotourism management concepts.Verification is carried out through geological observations by exploring 7 (seven) clusters from the top to the foot of Mount Ireng to verify 53 Assessment Matrices including Criteria, Comparisons, Classifications (Scientific Values, Education and Tourism), Threat of Damage / Risk of Degradationand Utilization Recommendations. Hope is Mount Ireng, in the Srumbung Hamlet, Pengkok Village, Patuk Subdistrict, Gunung Kidul Regency, Special Region of Yogyakarta, which is believed to be the Ancient Volcanic Center Faces can become a Geological Nature Reserve Area (KCAG).
    Citations (1)
    Abstract Merapi volcano has a well-known eruption type, namely Merapi type, in which an extruded lava dome collapses and is accompanied by pyroclastic density current (PDC). This type of eruption makes morphological monitoring of the lava dome crucial in the hazard mitigation process. After the VEI 4 eruption in 2010, a new lava dome of Merapi appeared on top of the 2010 lava dome in August 2018 and continuously grew. In November 2019, the lava dome started to collapse outward the crater area. We reported the lava dome morphological monitoring using a UAV (Unmanned Aerial Vehicle) photogrammetry conducted from August 2018 to February 2019. This UAV monitoring provides processed aerial photo data in Digital Terrain Model (DTM) and orthophoto with low operating costs and short data acquisition time. The lava domes erupted from the same eruptive canter within this period and grew evenly in all directions. The 2018-2019 Merapi lava dome has basal ratio of 0.183 to 0.290 with height of 11 to 41 m, respectively. Volume changed from 33,623 m 3 in August 2018 to 658,075 m 3 in February 2019, suggesting growth rate at ~3,500 m 3 /day. The lava base filled the crater base area (0.21 km 2 ) and started to collapse outward in November 2019.
    Lava dome
    Dome (geology)
    Lava field
    Orthophoto
    : Lava flow and lava dome growth are two main manifestations of effusive volcanic eruptions. Less-viscous lava tends to flow long distances depending on slope topography, heat exchange with the surroundings, eruption rate, and the erupted magma rheology. When magma is highly viscous, its eruption on the surface results in a lava dome formation, and an occasional collapse of the dome may lead to a pyroclastic flow. In this chapter, we consider two models of lava dynamics: a lava flow model to determine the internal thermal state of the flow from its surface thermal observations, and a lava dome growth model to determine magma viscosity from the observed lava dome morphological shape. Both models belong to a set of inverse problems. In the first model, the lava thermal conditions at the surface (at the interface between lava and the air) are known from observations, but its internal thermal state is unknown. A variational (adjoint) assimilation method is used to propagate the temperature and heat flow inferred from surface measurements into the interior of the lava flow. In the second model, the lava dome viscosity is estimated based on a comparison between the observed and simulated morphological shapes of lava dome shapes using computer vision techniques.
    Lava dome
    Effusive eruption
    Dome (geology)
    Citations (0)
    Usu volcano has erupted eight times since 1663. The last four eruptions took place in the 20th century, and were monitored using standard instruments. Only the 1944 eruption produced a lava dome with a mound. However, growth of the lava dome and the mound beneath have not been discussed quantitatively because direct data of the dome formation were not obtained. During the early period of the 1944 eruption, T. Minakami repeated precise levels along the road traversing the eastern foot of Usu volcano which had grown to a part of the new dome (Showa-shinzan). The surveying period covered the stages of precursory upheaval, mound upheaval, explosions, and finally, lava dome extrusion. Though the surveying route grazed the upheaving mound, the results of the precise levels prove to be extremely useful in deriving a pseudo growth curve for the mound and the lava dome. The growth curves afford us important information on ground upheavals and lava dome extrusions. Such knowledge can not be obtained by model experiments or theoretical simulations.
    Dome (geology)
    Lava dome
    Citations (15)
    Imaging growing lava domes has remained a great challenge in volcanology due to their inaccessibility and the severe hazard of collapse or explosion. Changes in surface movement, temperature, or lava viscosity are considered crucial data for hazard assessments at active lava domes and thus valuable study targets. Here, we present results from a series of repeated survey flights with both optical and thermal cameras at the Caliente lava dome, part of the Santiaguito complex at Santa Maria volcano, Guatemala, using an Unoccupied Aircraft System (UAS) to create topography data and orthophotos of the lava dome. This enabled us to track pixel-offsets and delineate the 2D displacement field, strain components, extrusion rate, and apparent lava viscosity. We find that the lava dome displays motions on two separate timescales, (i) slow radial expansion and growth of the dome and (ii) a narrow and fast-moving lava extrusion. Both processes also produced distinctive fracture sets detectable with surface motion, and high strain zones associated with thermal anomalies. Our results highlight that motion patterns at lava domes control the structural and thermal architecture, and different timescales should be considered to better characterize surface motions during dome growth to improve the assessment of volcanic hazards.
    Dome (geology)
    Lava dome
    Citations (31)