On the link between Earth tides and volcanic degassing
Artikel i vetenskaplig tidskrift, 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.

Författare

Florian Dinger

Universität Heidelberg

Max Planck-institutet

Stefan Bredemeyer

GEOMAR - Helmholtz Zentrum für Ozeanforschung Kiel

Deutsches GeoForschungsZentrum (GFZ)

Santiago Arellano

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys

Nicole Bobrowski

Max Planck-institutet

Universität Heidelberg

Ulrich Platt

Universität Heidelberg

Max Planck-institutet

Thomas Wagner

Max Planck-institutet

Solid Earth

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

Vol. 10 725-740

Fundament

Grundläggande vetenskaper

Ämneskategorier

Geofysik

DOI

10.5194/se-10-725-2019

Mer information

Senast uppdaterat

2019-07-12