Russian Scientists Assess Dangers of Internal Waves During Underwater Volcanic Eruptions
Mathematicians at HSE University in Nizhny Novgorod and the A.V. Gaponov-Grekhov Institute of Applied Physics of the Russian Academy of Sciences studied internal waves generated in the ocean after the explosive eruption of an underwater volcano. The researchers calculated how the waves vary depending on ocean depth and the radius of the explosion source. It turns out that the strongest wave in the first group does not arrive immediately, but after a significant delay. This data can help predict the consequences of eruptions and enable advance preparation for potential threats. The article has been published in Natural Hazards. The research was carried out with support from the Russian Science Foundation (link in Russian).
Layers of water with varying temperature, density, and salinity form in an ocean column. Internal waves arise at the boundaries of these layers due to external forces such as wind, currents, earthquakes, and volcanic eruptions, which cause the upper and lower layers to shift relative to each other. The boundary starts to oscillate, attempting to return to its original position under the influence of buoyancy forces. Since the density difference between the layers is small, internal waves have a larger amplitude (usually 5–20 metres but sometimes up to 150 metres) compared to surface waves, where the density contrast between water and air is much greater.
Although the speeds of internal waves are relatively slow (typically only a few dozen centimetres per second), they can still pose a serious threat to hydraulic structures, underwater gas and oil pipelines, and can also lead to the erosion of the ocean floor. Disasters involving at least three submarines have been attributed to the effects of internal waves: the two American atomic submarines, USS Thresher in 1963 and USS Scorpion in 1968, and the Indonesian diesel submarine KRI Nanggala-402 in 2021.
‘During underwater volcanic eruptions and earthquakes, the primary danger comes from surface tsunami waves, which can have amplitudes of up to 30 meters on the coast and can be highly destructive. Internal waves are typically not considered in such cases. However, a recent article by Chinese colleagues reported for the first time the observation of internal waves during a volcanic eruption in the Tonga Archipelago in 2022. This sparked our interest in studying the characteristics of internal waves,’ explains co-author of the study Ekaterina Didenkulova, Leading Research Fellow at the International Laboratory of Dynamical Systems and Applications at HSE University in Nizhny Novgorod.
Le Mehaute’s parabolic cavern was chosen as a source of tsunami waves. This model is commonly used to calculate surface tsunami waves generated by underwater explosions, volcanic eruptions, and meteorite impacts in water. It was considered that the curves connecting points with the same seawater density (isopycnals) bend over an underwater volcano in the same way as the water surface.
Calculations reveal that internal waves generated by the eruption of an underwater volcano form frequency-modulated groups, with the first group exhibiting the largest amplitude. The characteristics of internal waves depend on the ratio of layer thicknesses, the source radius, and the distance from the source. Even at relatively small distances from the source, the wave amplitudes change gradually, allowing the source of a tsunami to be identified from internal waves using remote sensing of the sea surface. This approach makes it possible to obtain additional information about the tsunami and mitigate potential damage caused by the disaster.
'The amplitudes of the waves in the remote zone are a percentage of their height at the source, but when translated into real numbers, they can correspond to several metres. Thus, the eruption site of the Krakatoa volcano in 1883 had a height of 200 metres and a radius of three kilometres. Our calculations indicate that the height of an internal wave at a distance of 300 kilometres can be around 10 meters, which could still pose a danger,' comments Efim Pelinovsky, Chief Research Fellow at the International Laboratory of Dynamical Systems and Applications at HSE University in Nizhny Novgorod.
See also:
HSE University Scholars Uncover E-Learning Preferences of Top Students
HSE University experts have analysed students’ digital footprints and shown for the first time that final grades depend on one’s personal approach to an online course. Balanced students have proven to be more successful than those who follow a more traditional and practical approach. The findings from this study will help create a more adaptive and personalised educational system. This research has been published in the journal The Internet and Higher Education.
HSE Scientists Develop Method to Stabilise Iodine in Solar Cells
Scientists at HSE MIEM, in collaboration with colleagues from China, have developed a method to improve the durability of perovskite solar cells by addressing iodine loss from the material. The researchers introduced quaternary ammonium molecules into the perovskite structure; these molecules form strong electrostatic pairs with iodine ions, effectively anchoring them within the crystal lattice. As a result, the solar cells retain more than 92% of their power after a thousand hours of operation at 85°C. The study has been published in Advanced Energy Materials.
HSE Researchers Create Genome-Wide Map of Quadruplexes
An international team, including researchers from HSE University, has created the first comprehensive map of quadruplexes—unstable DNA structures involved in gene regulation. For the first time, scientists have shown that these structures function in pairs: one is located in a DNA region that initiates gene transcription, while the other lies in a nearby region that enhances this process. In healthy tissues, quadruplexes regulate tissue-specific genes, whereas in cancerous tissues they influence genes responsible for cell growth and division. These findings may contribute to the development of new anticancer drugs that target quadruplexes. The study has been published in Nucleic Acids Research.
Mathematician from HSE University–Nizhny Novgorod Solves Equation Considered Unsolvable in Quadratures Since 19th Century
Mathematician Ivan Remizov from HSE University–Nizhny Novgorod and the Institute for Information Transmission Problems of the Russian Academy of Sciences has made a conceptual breakthrough in the theory of differential equations. He has derived a universal formula for solving problems that had been considered unsolvable in quadratures for more than 190 years. This result fundamentally reshapes one of the oldest areas of mathematics and has potential to have important implications for fundamental physics and economics. The paper has been published in Vladikavkaz Mathematical Journal.
Scientists Reveal How Language Supports Complex Cognitive Processing in the Brain
Valeria Vinogradova, a researcher at HSE University, together with British colleagues, studied how language proficiency affects cognitive processing in deaf adults. The study showed that higher language proficiency—regardless of whether the language is signed or spoken—is associated with higher activity and stronger functional connectivity within the brain network responsible for cognitive task performance. The findings have been published in Cerebral Cortex.
HSE AI Research Centre Simplifies Particle Physics Experiments
Scientists at the HSE AI Research Centre have developed a novel approach to determining robustness in deep learning models. Their method works eight times faster than an exhaustive model search and significantly reduces the need for manual verification. It can be applied to particle physics problems using neural networks of various architectures. The study has been published in IEEE Access.
Scientists Show That Peer Influence Can Be as Effective as Expert Advice
Eating habits can be shaped not only by the authority of medical experts but also through ordinary conversations among friends. Researchers at HSE University have shown that advice from peers to reduce sugar consumption is just as effective as advice from experts. The study's findings have been published in Frontiers in Nutrition.
‘Our Subject Is Absolute Truth in the Literal Sense’
What path does one have to follow to become a theoretical mathematician? Is there such a thing as a ‘mathematical personality’? And is it really true that all mathematicians are a bit eccentric? Valery Gritsenko, Professor at the Faculty of Mathematics and Head of the International Laboratory for Mirror Symmetry and Automorphic Forms, talks about 13-year-long referee reports and good films about mathematics.
HSE University Develops Tool for Assessing Text Complexity in Low-Resource Languages
Researchers at the HSE Centre for Language and Brain have developed a tool for assessing text complexity in low-resource languages. The first version supports several of Russia’s minority languages, including Adyghe, Bashkir, Buryat, Tatar, Ossetian, and Udmurt. This is the first tool of its kind designed specifically for these languages, taking into account their unique morphological and lexical features.
HSE Scientists Uncover How Authoritativeness Shapes Trust
Researchers at the HSE Institute for Cognitive Neuroscience have studied how the brain responds to audio deepfakes—realistic fake speech recordings created using AI. The study shows that people tend to trust the current opinion of an authoritative speaker even when new statements contradict the speaker’s previous position. This effect also occurs when the statement conflicts with the listener’s internal attitudes. The research has been published in the journal NeuroImage.