Symbol | Units | Description |
---|---|---|

Thermodynamics | ||

kJ mol^{−1} | Gibbs free energy at the P and T of interest | |

kJ mol^{−1} | Gibbs free energy at 1 bar and T of interest | |

R | J mol^{−1}K^{−1} | Gas constant |

K_{i} | – | Equilibrium constant for a generic reaction i |

ΔV | J bar^{−1} | Difference of the molar volumes of the products minus those of the reactants opportunely expanded and compressed at P and T of interest |

a_{i} | – | Activity of a generic phase i (calculated according to solution models; see text) |

bar | Oxygen fugacity | |

– | Mole fraction of water in the melt | |

– | Mole fraction of CO_{2} in the melt | |

Geophysical parameters | ||

Q_{degas} | m^{3} s^{−1} | Total magma degassing rate |

M_{S} | g mol^{−1} | Sulphur molecular mass |

g^{} mol^{−1} | Sulphur dioxide molecular mass | |

kg^{} s^{−1} | Sulphur degassing rate | |

ρ_{M} | kg^{} m^{−3} | Density of the magma |

Q_{in–steady} | m^{3} s^{−1} | Magma input rate during steady state |

Q_{in–ex} | m^{3} s^{−1} | Magma input rate in excess |

V_{in–steady} | m^{3} | Magma volume entering in the degassing zone during steady state |

V_{in–ex} | m^{3} | Magma volume in excess entering in the degassing zone |

V_{out} | m^{3} | Generic volume transferred outside the chamber |

V_{R} | m^{3} | Total volume of the reservoir |

T | days | Time since the beginning of eruption |

τ | days | Time constant of the exponential decay |

C | m^{3} Pa^{−1} | Capacity of the reservoir |

R_{e} | Pa s m^{−3} | Resistance of the conduit |

ρ_{e} | kg^{} m^{−3} | Density of the erupted magma |

P_{0} | Pa | Initial overpressure |

β_{R} | Pa^{−1} | Wallrock compressibility |

β_{M} | Pa^{−1} | Magma compressibility |

ρ_{l} | kg^{} m^{−3} | Density of the liquidus |

ρ_{g} | kg^{} m^{−3} | Density of the gas mixture |

*SO

_{2}values are from the Istituto Nazionale di Geofisica e Vulcanologia, INGV http://www.pa.ingv.it/comunicati/Stromboli/comunicati_stromboli.php