Thermal Remote Sensing for Global Volcano Monitoring: Experiences From the MIROVA System

Volcanic activity is always accompanied by the transfer of heat from the Earth’s crust to the atmosphere. This heat can be measured from space and its measurement is a very useful tool for detecting volcanic activity on a global scale. MIROVA (Middle Infrared Observation of Volcanic Activity) is an automatic volcano hot spot detection system, based on the analysis of MODIS data (Moderate Resolution Imaging Spectroradiometer). The system is able to detect, locate and quantify thermal anomalies in near real-time, by providing, on a dedicated website (www.mirovaweb.it), infrared images and thermal flux time-series on over 200 volcanoes worldwide. Thanks to its simple interface and intuitive representation of the data, MIROVA is currently used by several volcano observatories for daily monitoring activities and reporting. In this paper, we present the architecture of the system and we provide a state of the art on satellite thermal data usage for operational volcano monitoring and research. In particular, we describe the contribution that the thermal data have provided in order to detect volcanic unrest, to forecast eruptions and to depict trends and patterns during eruptive crisis. The current limits and requirements to improve the quality of the data, their distribution and interpretation are also discussed, in the light of the experience gained in recent years within the volcanological community. The results presented clearly demonstrate how the open access of satellite thermal data and the sharing of derived products allow a better understanding of ongoing volcanic phenomena, and therefore constitute an essential requirement for the assessment of volcanic hazards

Thermal Remote Sensing for Global Volcano Monitoring: Experiences From the MIROVA System

Volcanic activity is always accompanied by the transfer of heat from the Earth's crust to the atmosphere. This heat can be measured from space and its measurement is a very useful tool for detecting volcanic activity on a global scale. MIROVA (Middle Infrared Observation of Volcanic Activity) is an automatic volcano hot spot detection system, based on the analysis of MODIS data (Moderate Resolution Imaging Spectroradiometer). The system is able to detect, locate and quantify thermal anomalies in near real-time, by providing, on a dedicated website (www.mirovaweb.it), infrared images and thermal flux time-series on over 200 volcanoes worldwide. Thanks to its simple interface and intuitive representation of the data, MIROVA is currently used by several volcano observatories for daily monitoring activities and reporting. In this paper, we present the architecture of the system and we provide a state of the art on satellite thermal data usage for operational volcano monitoring and research. In particular, we describe the contribution that the thermal data have provided in order to detect volcanic unrest, to forecast eruptions and to depict trends and patterns during eruptive crisis. The current limits and requirements to improve the quality of the data, their distribution and interpretation are also discussed, in the light of the experience gained in recent years within the volcanological community. The results presented clearly demonstrate how the open access of satellite thermal data and the sharing of derived products allow a better understanding of ongoing volcanic phenomena, and therefore constitute an essential requirement for the assessment of volcanic hazards. Peer reviewe

Analisis Petrografi dan Kimia Mineral Batuan Volkanik Letusan Gunung Sinabung Tahun 2016

Gunung Sinabung terletak di Kabupaten Karo, Provinsi Sumatera Utara. Letusan Gunung Sinabung kembali terjadi pada tahun 2010 setelah erupsi magmatik terakhir terjadi pada 1150 ± 50 tahun yang lalu. Berdasarkan analisis petrografi dan kimia mineral, terdapat dua macam penggerombolan mineral (clots) pada sampel batuan volkanik hasil letusan Gunung Sinabung pada tahun 2016 yaitu penggerombolan mineral (clots) plagioklas (labradorit, bitownit), hornblenda (magnesio-hornblenda), dan mineral opak serta plagioklas (labradorit, bitownit), piroksen (augit, pigeonit, enstatit), dan mineral opak. Geotermometer dua piroksen (klinopiroksen dan ortopiroksen) yang berdampingan pada penggerombolan mineral (clots) menunjukkan bahwa magma andesitik Gunung Sinabung memiliki temperatur sekitar 930-1010˚C dan 750-880˚C berdasarkan geotermometer hornblenda dan plagioklas. Kehadiran reverse zoning pada plagioklas, tekstur mikro plagioklas yang dominan berupa tekstur fine sieve, resorption surface, dan fine-scale oscillatory zoning serta tekstur batuan dan mineral yang lainnya mengindikasikan adanya proses recharge magma dan percampuran magma yang mengakibatkan perubahan kondisi magma Gunung Sinabung. Kata kunci: gunung sinabung, petrografi, kimia mineral, clots, geotermometer, magm

The velocity structure of the volcanic plumbing system of Gede Volcano, West Java, Indonesia

We estimated the velocity structure beneath four three-component broad-band seismic stations and three short period stations in the Gede Volcano region, West Java, Indonesia by the receiver function (RF) technique jointly with H/V (Horizontal/Vertical) amplitude ratio of Rayleigh waves to constrain the 1D velocity structure around each station, and in the back-azimuth of the source considered, ultimately providing a 3D understanding of the velocity structure of the volcanic plumbing system. The stations are part of the collaborative seismological network between Center for Volcanology and Geological Hazard Mitigation (CVGHM) and Earth Observatory of Singapore (EOS). Our preliminary result suggest the depth of the Moho is about 30 km. Based on the back azimuth of the earthquakes, the receiver functions inversion and H/V amplitude radio from the earthquakes coming from the NE-SE direction exhibit strong negative signals between direct P and Pms phase correspond to a low velocity layer in the crust, predominating all broadband station stations. This is consistent with the result of previous study of travel time tomography. We observed very few earthquakes from SW-NW direction where the receiver functions show differently from the first group due to the waves travel to magmatic body. Combining results from this study and the tomography we aim is to further find the magmatic body under the volcano at shallow as well as deeper depths. Since we have 10-year data, we will be able to see the yearly evolution or changes of the magmatic system under the volcano

Petrological and Geochemical Study of Sundoro Volcano, Central Java, Indonesia: Temporal Variations in Differentiation and Source Processes during the Growth of an Individual Volcano

Volcanic rocks of the Java sector of Sunda arc have a wide range of isotopic compositions that indicate significant addition of subjected sediment. What processes control these geochemical characteristics is a topic of long-standing debate. Here we report Sr-Nd-Pb radiogenic isotope ratios and geochemical data from stratigraphically well-constrained rocks of Sundoro volcano in central Java that represent the volcano's activity since 34 ka. The rocks range from basalt (51 wt SiO2) to andesite (63 wt SiO2) and are dominated by basaltic andesite. We divide them into magma types A, B and C, having low, medium and high 87Sr/86Sr and Pb isotopic ratios, respectively. According to various differentiation indices, the three magma types have separate, parallel 87Sr/86Sr, Ba/Zr and La/Yb trends and disparate Pb isotopic trends. The dominant process of intracrustal differentiation appears to be magma mixing, in which each of the three magma types represents the mixing of a distinct mafic end-member and a distinct felsic end-member. The distinct geochemical profiles of these magma types indicate that the three mafic end-members are genetically unrelated and that their differences may represent characteristics of their magma sources. On the basis of trace element ratios (Ba/Yb and La/Yb) and Sr-Nd-Pb isotopic compositions, we estimate that magma types A, B and C represent mantle wedge materials fluxed by ~1, ~1.5 and ~2 slab-derived materials containing 50, 55 and 65 sediment component, respectively, reflecting increasing proportions of sediments and increasing slab flux. Geochemical data from Merapi volcano, interpreted using the same approach, reveal a similar increase in the slab-derived flux to the magma source, raising the possibility that such short-lived variations in magma genesis, perhaps related to the subduction of bathymetric relief features, characterize the unusual magmatism beneath the volcanic front of the central Java sector of the Sunda arc. © 2022 The Author(s). Published by Oxford University Press. All rights reserved

New Insights into Magma Differentiation and Storage in Holocene Crustal Reservoirs of the Lesser Sunda Arc: the Rinjani–Samalas Volcanic Complex (Lombok, Indonesia)

International audienc

Dynamics of the major plinian eruption of Samalas in 1257 A.D. (Lombok, Indonesia)

International audienc