Contemporary State of the Elbrus Volcanic Center (The Northern Caucasus)

Abstract

The Elbrus volcanic center is located in southern Russia on the northern slope of the main ridge of the Greater Caucasus. Current classifications define Elbrus as a dormant volcano that could become active even after millennia of quiescence. In this study, we use two new geophysical methods to assess the contemporary state of the Elbrus volcano. The first method is based on an evaluation of parameters of resonant modes “reemitted” by the resonant structure (i.e., volcanic chamber) in response to the excitation of a seismic impact and recorded by a precise laser interferometer–strainmeter. The second method is based on lowfrequency microseismic sounding and allows determination of the deep structure of complicated geological objects. Our study locates the magma chamber at depths of 1–8 km and extended magma source at depths of 15–40 km beneath the Elbrus eastern summit. An unknown magmatic structure, comparable to the Elbrus magmatic structure but currently much colder, was also identified 50 km from Mt. Elbrus. Based on our analysis, we assess the Elbrus volcano to be currently in a quasi-stable state of thermodynamic equilibrium.