On the link between Earth tides and volcanic degassing
Journal article, 2019

Long-term measurements of volcanic gas emissions conducted during the last decade suggest that under certain conditions the magnitude or chemical composition of volcanic emissions exhibits periodic variations with a period of about 2 weeks. A possible cause of such a periodicity can be attributed to the Earth tidal potential. The phenomenology of such a link has been debated for long, but no quantitative model has yet been proposed. The aim of this paper is to elucidate whether a causal link between tidal forcing and variations in volcanic degassing can be traced analytically. We model the response of a simplified magmatic system to the local tidal gravity variations and derive a periodical vertical magma displacement in the conduit with an amplitude of 0.1-1m, depending on the geometry and physical state of the magmatic system. We find that while the tide-induced vertical magma displacement presumably has no significant direct effect on the volatile solubility, the differential magma flow across the radial conduit profile may result in a significant increase in the bubble coalescence rate at a depth of several kilometres by up to several multiples of 10%. Because bubble coalescence facilitates separation of gas from magma and thus enhances volatile degassing, we argue that the derived tidal variation may propagate to a manifestation of varying volcanic degassing behaviour. The presented model provides a first basic framework which establishes an analytical understanding of the link between the Earth tides and volcanic degassing.

Author

Florian Dinger

Max Planck Society

Heidelberg University

Stefan Bredemeyer

Helmholtz

German Research Centre for Geosciences (GFZ)

Santiago Arellano

Chalmers, Space, Earth and Environment, Microwave and Optical Remote Sensing

Nicole Bobrowski

Heidelberg University

Max Planck Society

Ulrich Platt

Max Planck Society

Heidelberg University

Thomas Wagner

Max Planck Society

Solid Earth

1869-9510 (ISSN) 1869-9529 (eISSN)

Vol. 10 725-740

Roots

Basic sciences

Subject Categories

Geophysics

DOI

10.5194/se-10-725-2019

More information

Latest update

9/15/2020