New research study by Hungarian researchers is helping to reveal the signs before such a volcano erupts.A team from the ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, and the HUN-REN-ELTE Volcanology Research Group, in cooperation with other scientists from Europe, studied Ciomadul, the youngest volcano in the Carpathian-Pannonian region.Using high-resolution integrated mineral texture and chemical structure information, they quantified the conditions of magma evolution, reconstructed the architecture of the subvolcanic magma tank, identified the attributes of the resident crystal mush and the recharge lavas, which triggered the eruptions, and explained why volcanic activity in the last active duration ended up being primarily explosive.The website of the most current eruption of Ciomadul: the St Ana crater.Credit: István FodorCiomadul: A Typical Long Dormant VolcanoThe eruptive history of Ciomadul was previously revealed by the research study team utilizing U-Th-Pb-He geochronology of a tiny crystal, zircon. Some amphiboles represent a low-temperature, extremely crystalline lava reservoir at depths of 8-12 kilometers, but most of them were transferred to this shallow magma storage by higher-temperature recharge magmas coming from higher depths.The rebuilded magma tank system beneath Ciomadul volcano throughout the last eruptive period from 56 to 30 thousand years back. Credit: Bianca Németh” Compared to the previous, lava dome-forming eruptive period, these fresh recharge magmas carried amphibole with a distinct composition, i.e. these lavas were slightly various, and this might play an important role in why the eruption became explosive,” Harangi points out. They analyzed such amphibole as an early formation phase in ultra-hydrous lavas, and these water-rich recharge lavas might have played a key role in activating the explosive eruptions.The structure of the outermost rim of the crystals and of the iron-titanium oxides supplied info about the lava condition just prior to the eruptions. Quantitative volcano petrology studies are essential to rebuild the subvolcanic lava tank structure and the lava storage conditions, which can likewise help us in eruption forecasting to better comprehend the pre-eruption signals.
Scientists have actually studied the Ciomadul volcano to understand how long-dormant volcanoes can all of a sudden erupt. Their findings on the chemical and mineral structure of the lava provide valuable insights into volcanic reactivation and eruption forecasting, highlighting the possible risks of non-active volcanoes. Credit: SciTechDaily.com Even in a peaceful inactive phase, a volcano can quickly become active and its eruption can position a formerly unknown risk to the surrounding area.Can a volcano appear after tens of thousands of years of inactivity? If so, how can this be described and what makes volcanic eruptions more harmful, i.e. explosive? These are key questions in volcanic hazard evaluation and can likewise accentuate volcanoes that seem inactive. Even in a quiet inactive stage, a volcano can rapidly become active and its eruption can posture a formerly unidentified hazard to the surrounding location. New research study by Hungarian researchers is assisting to reveal the signs before such a volcano erupts.A group from the ELTE Eötvös Loránd University, Institute of Geography and Earth Sciences, and the HUN-REN-ELTE Volcanology Research Group, in cooperation with other scientists from Europe, studied Ciomadul, the youngest volcano in the Carpathian-Pannonian region.Using high-resolution integrated mineral texture and chemical structure information, they quantified the conditions of magma evolution, reconstructed the architecture of the subvolcanic magma tank, identified the qualities of the local crystal mush and the recharge magmas, which activated the eruptions, and discussed why volcanic activity in the last active duration became primarily explosive.The site of the most recent eruption of Ciomadul: the St Ana crater.Credit: István FodorCiomadul: A Typical Long Dormant VolcanoThe eruptive history of Ciomadul was formerly revealed by the research team using U-Th-Pb-He geochronology of a tiny crystal, zircon. Szabolcs Harangi, professor and leader of the research study project, highlighted that “there have been numerous extended periods of dormancy in the nearly million-year life of the volcano, but even after 10s of thousands, often much more than 100,000 years of quiescence, volcanic eruptions started again!” The most considerable volcanism took place in the last 160,000 years, with lava domes extrusions in between 160 and 95 thousand years back, and after that, after more than 30 thousand years of dormancy, eruptions resumed 56 thousand years ago.Barbara Cserép, a PhD student at ELTE, is studying the youngest eruption products: “They were formed by more unsafe, explosive eruptions compared to the previous active episode. So, it is essential to know what was the reason for this modification in eruption design!” The last volcanic eruptions took place 30,000 years back, and given that then the volcano has been inactive again.Working on the pyroclastic sequence of the very first explosive eruption events of Ciomadul after long dormancy. Credit: Bianca NémethA Petrodetective WorkThe cause of the volcanic eruption initiation and the procedures that manage the eruption design are hidden in the rocks formed during the volcanic activity. These can be revealed by the in-depth study of the rock-forming minerals. The research team determined the chemical structure of all the mineral phases, typically at high resolution from the crystal core to the rim, in the pumices formed throughout the explosive volcanism from 56 to 30,000 years ago.They then critically evaluated the outcomes of numerous techniques for determining formation temperature level, pressure, redox state, melt composition and melt water content to quantify the lava conditions and also to constrain how these crystals were included into the emerging magma. This assisted to decipher the architecture of the magma reservoir system, the processes that lead to eruptions, and to discuss the explosive eruptions.The Key to Explosive EruptionsThe secret player in this petrodetective research study was a mineral, called amphibole. “Many components can enter into the crystal lattice of amphibole, but the component replacements are highly controlled by the magma conditions” describes Barbara Cserép. The chemical structure of amphibole in the Ciomadul pumices shows a large variation even in single sample. Some amphiboles represent a low-temperature, highly crystalline magma reservoir at depths of 8-12 kilometers, however the majority of them were transported to this shallow lava storage by higher-temperature recharge magmas coming from higher depths.The reconstructed magma tank system underneath Ciomadul volcano during the last eruptive duration from 56 to 30 thousand years back. Credit: Bianca Németh” Compared to the previous, lava dome-forming eruptive period, these fresh recharge magmas carried amphibole with a distinct composition, i.e. these lavas were slightly different, and this could play an important role in why the eruption became explosive,” Harangi points out.” We determined several amphiboles with a chemical structure not reported in volcanic rocks from other volcanoes,” adds Cserép, as an essential outcome of the research study. They translated such amphibole as an early formation stage in ultra-hydrous magmas, and these water-rich recharge lavas might have played a crucial function in triggering the explosive eruptions.The composition of the outermost rim of the crystals and of the iron-titanium oxides offered details about the lava condition just prior to the eruptions. Postdoctoral researcher Máté Szemerédi, another lead author of the research study, stated, “The structure of iron-titanium oxides equilibrates in a few days when the lava condition changes; they indicate that the appeared magma was at 800-830 degrees Celsius and was oxidized.” The Importance of the Ciomadul VolcanoAt present, the Ciomadul volcano shows no indications for reawakening. However, this study likewise explains that reactivation can happen rapidly, within weeks or months, in case of recharge by hot, hydrous magma. Quantitative volcano petrology research studies are important to rebuild the subvolcanic magma tank structure and the magma storage conditions, which can likewise assist us in eruption forecasting to much better understand the pre-eruption signals.” This research is unique in the sense that it is carried out in a long-dormant volcano, and as an outcome, the Ciomadul volcano is getting an increasing worldwide attention,” Szabolcs Harangi explains. This assists to highlight that, in addition to the 1500 approximately possibly active volcanoes on Earth, long-dormant volcanoes can also position a previously not recognized danger, especially if there is still melt-bearing magma beneath them.Reference: “Constraints on the pre-eruptive lava storage conditions and lava evolution of the 56– 30 ka explosive volcanism of Ciomadul (East Carpathians, Romania)” by Barbara Cserép, Máté Szemerédi, Szabolcs Harangi, Saskia Erdmann, Olivier Bachmann, István Dunkl, Ioan Seghedi, Katalin Mészáros, Zoltán Kovács, Attila Virág, Theodoros Ntaflos, David Schiller, Kata Molnár and Réka Lukács, 28 November 2023, Contributions to Mineralogy and Petrology.DOI: 10.1007/ s00410-023-02075-z.
