Lava Volume from Remote Sensing Data: Comparisons with Reverse Petrological Approaches for Two Types of Effusive Eruption

Pauline Verdurme,Andrew J L Harris,Diego Coppola,Andrea Di Muro,Lucia Gurioli,Simon Carn,Santiago Arellano

doi:10.3390/rs14020323

Abstract

Five effusive eruptions of Piton de la Fournaise (La Réunion) are analyzed to investigate temporal trends of erupted mass and sulfur dioxide (SO2) emissions. Daily SO2 emissions are acquired from three ultraviolet (UV) satellite instruments (the Ozone Monitoring Instrument (OMI), the Ozone Mapping and Profiler Suite (OMPS), and the Tropospheric Monitoring Instrument (TROPOMI)) and an array of ground-based UV spectrometers (Network for Observation of Volcanic and Atmospheric Change (NOVAC)). Time-averaged lava discharge rates (TADRs) are obtained from two automatic satellite-based hot spot detection systems: MIROVA and MODVOLC. Assuming that the lava volumes measured in the field are accurate, the MIROVA system gave the best estimation of erupted volume among the methods investigated. We use a reverse petrological method to constrain pre-eruptive magmatic sulfur contents based on observed SO2 emissions and lava volumes. We also show that a direct petrological approach using SO2 data might be a viable alternative for TADR estimation during cloudy weather that compromises hot spot detection. In several eruptions we observed a terminal increase in TADR and SO2 emissions after initial emission of evolved degassed magma. We ascribe this to input of deeper, volatile-rich magma into the plumbing system towards the end of these eruptions. Furthermore, we find no evidence of volatile excess in the five eruptions studied, which were thus mostly fed by shallow degassed magma.

Highlights

SO2 masses calculated from measured from ground-based stations for the five selected eruptions (Figure measured from ground-based NOVAC stations for the five selected eruptions (Figure 3)
2015, where where the same trends were apparent in all datasets (OMPS, Ozone Monitoring Instrument (OMI), and NOVAC)
Manual processing of MODIS data validates the efficiency of hot spot detection and Time-averaged lava discharge rates (TADRs)-derivation by the MIROVA system during the effusive eruptions at Piton de la Fournaise, meaning that the conversion coefficient in Equation (5) is valid

Summary

Introduction

Volcanic eruptions are associated with a multitude of geophysical and geochemical signals, including seismicity (e.g., seismic swarms and volcanic tremor), ground deformation, heat flux, and changes in gas emissions and composition. These signals can be detected and tracked by permanent ground stations and satellite observations [1]. Development of various technologies for near-real time and continuous data collection has led to improvements in volcano monitoring and tracking of their eruptive behavior. We combine ultraviolet (UV) and infrared (IR) satellite measurements [2,3,4,5,6,7,8]

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Discussion

Conclusion