Яндекс.Метрика

 Kh. Meliksetian, L. Sargsyan, I. Koulakov, N. Toghramadjian, N. Belovezhets, Y. Berezhnev, G. Navasardyan, E. Grigoryan, A. Vasilevsky, E. Sahakyan

Serial edition: Journal of Geophysical Research: Solid Earth
Volume: 131 , Уear of publication: 2026

Abstract

We perform Rayleigh wave ambient noise tomography to investigate crustal seismic velocity structure and sources of volcanism in Armenia. Armenia, a key part of the tectonically and volcanically active Caucasus-Anatolia region, is actively being deformed by the ongoing Arabian-Eurasian continental collision. Unlike typical intracontinental settings, Armenia exhibits exceptional diversity of volcanic compositions and eruption styles: large stratovolcanoes are interspersed among more broadly distributed monogenetic cones and extensive lava flows. This study presents the first seismic tomography model of Armenia with sufficient resolution to infer potential magma sources. We analyze 19 months of continuous ambient noise data recorded by 32 seismic stations, extracting Green's functions and Rayleigh wave dispersion curves. A two-step tomographic inversion first yields 2D group velocity maps, followed by a 3D shear-wave velocity model. Synthetic tests confirm the model's resolution and ability to detect lateral and vertical velocity anomalies. Our results reveal prominent low-velocity anomalies down to 25 km beneath monogenetic cones, likely indicating magma transport zones. At greater depths, velocity anomalies reverse sign. A high-velocity zone at 40 km depth beneath dispersed cones suggests crustal thinning and asthenosphere upwelling. Beneath Lake Sevan, we identify two distinct structures: a low-velocity anomaly in the NW linked to fault-related fracturing and fluid saturation, and a high-velocity anomaly in the SE that may represent a rigid block, possibly remnant oceanic crust. This study provides new insights into crustal structure beneath Armenia, shedding light on its magmatic and tectonic evolution.
индекс в базе ИАЦ: 018657