Even in a quiet dormant period, the volcano can quickly become active, and its eruptions can pose an unknown threat to the surrounding area. Researchers studied the Siomadur volcano to understand how the long-dormant volcano erupted suddenly. Their findings on the chemical and mineralogical composition of magma provide valuable insights into volcanic reactivation and eruption forecasting, highlighting the potential dangers of inactive volcanoes.
Can volcanoes erupt after tens of thousands of years of dormancy?If yes, how to explain it?What makes volcanic eruptions more dangerous, i.e., having a ** nature?These are all key issues in volcanic hazard assessment and can also draw attention to seemingly inactive volcanoes. Even during quiet dormant periods, volcanoes can quickly become active, and their eruptions can pose previously unknown threats to the surrounding area. New research by Hungarian scientists helps shed light on the signs that preceded such volcanic eruptions.
A team from the Institute of Geography and Earth Sciences of ELTE University in Hungary and the Hun-Ren-Elte Volcanology Research Group, in collaboration with other European scientists, conducted a study on Ciomodul, the youngest volcano in the Carpathian-Pannonian region.
Using high-resolution comprehensive data on mineral texture and chemical composition, they quantified the conditions for magma evolution, reconstructed the structure of the sub-volcanic magma reservoir, identified the characteristics of the resident crystalline mud and recharge magma that triggered the eruption, and explained why the volcanic activity during the last active period was dominated by **.
The site of the most recent eruption of the Theomadur volcano: Santa Ana Crater. **istván fodor
Theomadur: A typical long-dormant volcano
The team previously used the u-th-pb-he geochronology of a tiny crystal, zircon, to reveal the eruption history of Theomadur. Professor Szabolcs Harangi, the head of the research project, emphasized:"There have been several long periods of dormancy in the nearly a million years of the volcano's life, but even after tens of thousands of years of dormancy, sometimes more than 100,000 years, the eruption has begun again!"
The most significant volcanic activity occurred as recently as 160,000 years ago, and lava dome extrusion occurred between 160,000 years ago and 950,000 years ago, and then after more than 30,000 years of dormancy, the volcano erupted at 560,000 years ago to start over.
Barbara Cserép, a PhD student at ELTE University, is working on the youngest eruption: she says"They are formed by more dangerous and more critical eruptions than the previous active period. Therefore, it is very important to understand the reasons for this change in the way of eruption!"The last eruption occurred 30,000 years ago, and since then, the volcano has gone dormant again. "
To study the igneous debris sequence of the first **sexual eruption of the Siomadur volcano after a long hibernation. **bianca németh
The causes of volcanic eruptions and the processes that control how they erupt are hidden in the rocks formed during volcanic activity. These causes can be revealed through a detailed study of the minerals that form the rocks. The team determined the chemical composition of all mineral phases in pumice formed during a volcanic eruption between 56 and 30,000 years ago, often with a high-resolution determination from the crystal core to the edge.
They then critically evaluated the results of various methods for calculating crystallization temperature, pressure, redox state, melt composition, and melt moisture content to quantify magma conditions and determine how these crystals fit into the erupting magma. This helps to reveal the structure of the magmatic reservoir system, the processes that lead to the eruption, and the causes of the eruption.
The key to sexual eruptions
The key figure in this oil detective study is a mineral called amphibole. Barbara Cserép explains:"Many elements can enter the amphibole lattice, but the displacement of the elements is strongly controlled by magmatic conditions. The chemical composition of amphibole in ciomadul pumice varies greatly even in a single sample. Some amphiboles represent low-temperature, high-crystalline magma reservoirs at depths of 8-12 km, but most of the amphibole is transported to this shallow magma reservoir by high-temperature recharge magma from deeper depths. "
In 5 years agoDuring the last eruption between 60,000 and 30,000 years ago, the reconstructed magma reservoir system beneath the Theomadur volcano. **bianca németh
Compared to the last eruption period when the lava dome was formed, these fresh supply magma have a unique amphibole composition, that is, these magma are slightly different, which may be an important reason why the eruption became a ** volcano. "Cserép added:"We have found several species of amphibole with a chemical composition not reported in the volcanic rocks of other volcanoes. They interpret this amphibole as an early crystallization stage of superhydrous magma, and these water-rich recharge magmas may have played a key role in initiating the ** eruption. "
The outermost edge of the crystal and the composition of iron-titanium oxides provide information about the magmatic conditions before the eruption. Máté Szemerédi, another lead author of the study and a postdoctoral fellow, said:"When magmatic conditions change, the composition of iron-titanium oxides reaches equilibrium within a few days;They show that the eruption magma had a temperature of 800-830 degrees Celsius and was oxidized. "
At the moment, there is no sign of the awakening of the Siomadur volcano. However, the study also points to the fact that reactivation could occur rapidly within weeks or months if recharged with red-hot water-bearing magma. Quantitative volcanic petrology studies are important for reconstructing the structure of the underlying magmatic reservoir and magma storage conditions, which also helps us to predict eruptions and better understand the signals before volcanic eruptions.
Szabolcs Harangi points out"The novelty of this study is that it was carried out on a volcano that has been dormant for a long time, and for this reason, the Siomadur volcano is receiving increasing international attention. This helps to highlight that, in addition to the 1,500 or so potentially active volcanoes on Earth, long-dormant volcanoes can also pose previously unrecognized dangers, especially if lava-bearing magma remains underneath the volcanoes. "
Compiled from: scitechdaily