Response of Fogo volcano (Cape Verde) to lunisolar gravitational forces during the 2014–2015 eruption

https://doi.org/10.1016/j.pepi.2021.106659Get rights and content

Highlights

  • Joint analysis of tremor, SO2 emission and lava volume flow rate during Fogo eruption.

  • Geophysical time-series analyzed using Singular Spectrum Analysis (SSA).

  • 9 tidal periods identified ranging from 0.5 to ~14 days with predominance of lunar tides.

  • Fogo volcano respond as a bandpass filter to tidal oscillations.

Abstract

Volcanoes are complex systems that evolve in space and time as a result of their eruptive activity. Volcanic eruptions represent the ultimate expression of a complex interplay between internal and external processes that span across different time scales. Deciphering how internal and external processes interact at the time scale of eruptions may provide key insights on the temporal evolution of eruptions and also help to better evaluate associated volcanic hazards. Studies of the tidal influence on volcanic activity have fallen within this context, although the cause-effect relationship between tides and eruptions is still unclear. In this study, we used Singular Spectrum Analysis to analyze three time-series, namely the seismic tremor, SO2 emission and lava volume flow rate, which cover the first month of effusive activity at Fogo volcano, Cape Verde, in 2014–2015. We detect 9 tidal periodicities and up to 5 in each time-series ranging from semi-diurnal to fortnightly periods. We show that the movement of magma at crustal depths and at surface as well as gas emission during the effusive eruption are all modulated by lunisolar gravitational forces. We highlight the relevance of the volcano location on Earth, which together with the timing of the eruption, associated with a specific astronomical configuration, result in a specific combination of tides that directly influence the volcano eruptive activity. With this data set, we further investigate the response of Fogo volcano to this external forcing. We show that during the 2014–2015 eruption, Fogo volcano acted as a bandpass filter to quasi-permanent tidal oscillations.

Introduction

Periodicities corresponding to lunisolar tides have for long been observed in seismic and volcanic activity (Mauk and Johnston, 1973; Heaton, 1975; Sparks, 1981; Rymer and Brown, 1984; Bodri and Iizuka, 1989; Cigolini et al., 2009; Bredemeyer and Hansteen, 2014; Delorey et al., 2017; Petrosino et al., 2018; Ricco et al., 2019; Varga and Grafarend, 2019). In addition, recent studies have evidenced presence of tides at time scales ranging from a few days to decades, in the polar motion (Lopes et al., 2017), plate motion (Zaccagnino et al., 2020) and even in climate indexes as a response to the temporal evolution of atmospheric pressures (Le Mouël et al., 2019a). At volcanoes, periodic variations have been revealed by various kind of observations such as lava lake height, degassing, micro-seismicity and Long-Period (LP) events, volcanic tremor, ground tilt, temperature of fumarolic fields, energy radiated by lava or strength of eruptive phases (Golombek and Carr, 1978; Berrino and Corrado, 1991; Williams-Jones et al., 2001; Custodio et al., 2003; Sottili et al., 2007; Cigolini et al., 2009; De Lauro et al., 2012, De Lauro et al., 2013, De Lauro et al., 2018; Sottili and Palladino, 2012; Bredemeyer and Hansteen, 2014; Girona et al., 2018; Dinger et al., 2018; Caputo et al., 2020; Dumont et al., 2020; Petrosino et al., 2020). Lunisolar gravitational forces have also been evoked as triggers of volcanic eruptions (Mauk and Johnston, 1973; Dzurizin, 1980; Jentzsch et al., 2001; Dumont et al., 2020).

Different approaches have been considered to demonstrate the correlation between tidal action and variations in volcanic activity, from statistics to spectral or principal component analysis (see examples in Mauk and Johnston, 1973; Patanè et al., 1994; Girona et al., 2018; De Lauro et al., 2013; Dumont et al., 2020). The main and most frequent periodicities detected in time-series acquired at volcanoes are those of the fortnightly, which is induced by the Moon's declination, the semi-diurnal caused by the Sun and lunar elliptic trajectory, as well as the diurnal component which is related to the Sun (Berrino and Corrado, 1991; Custodio et al., 2003; Sottili and Palladino, 2012; De Lauro et al., 2018; Girona et al., 2018; Le Mouël et al., 2019b). These tidal oscillations are, however, not the only to modulate activity at volcanoes, as suggested by a couple of studies (Sottili and Palladino, 2012; Bredemeyer and Hansteen, 2014; Caputo et al., 2020; Dumont et al., 2020). In spite of all these studies, providing clear evidence on the correlation between processes that occur at very different time scales has proved to be particularly challenging. In addition and beyond the techniques used, the cause-effect relationship between tidal action and volcanic activity has remained elusive (Sparks, 1981; Neuberg, 2000). Tidal stresses and tidal acceleration have been suggested as the main drivers of tidal forcing although tidal stresses are about 3–5 orders of magnitude smaller than tectonic stresses (Mauk and Johnston, 1973; Sparks, 1981), which makes them too low to induce fracturing (McMillan et al., 2019; Dumont et al., 2020). The complexity of volcanic systems, which is mainly due to their eruptive history, composition, internal structure and tectonic setting, also plays an important role on how volcanoes respond to the quasi-permanent tidal oscillations explaining also why all volcanoes do not show a similar sensitivity to Earth tides (Mauk and Johnston, 1973; Dzurizin, 1980). Additionally, the specific positions of volcanoes on the planet, means they are not influenced similarly by the different Earth tides, as the zonal, tesseral and sectorial components of the tidal potential have a specific spatial distribution on Earth (see Jobert and Coulomb, 1973; chapter 18). The spatial distribution and especially the latitudinal position of the different gravitational bodies that interact with the volcano is determinant in the way the tidal potential applies on Earth (Mauk and Johnston, 1973; Hamilton, 1973; Jobert and Coulomb, 1973) .

In this study, we adopted a similar approach to Dumont et al. (2020) and used the Singular Spectrum Analysis to investigate three geophysical time-series, namely the SO2 emission, lava volume flow rate (VFR) and seismic tremor, spanning the 2014–2015 mix eruption at Fogo volcano, Cape Verde. This eruption started on 23 November 2014 and ended on 8 February , after 2.5 months of intense effusive activity (Mata et al., 2017; Richter et al., 2016). The resulting extensive lava field (~40-45 106 m3) covered ~4.5 km2 of Chã das Caldeiras and destroyed two villages (Richter et al., 2016; Jenkins et al., 2017; Bagnardi et al.(2016); Vieira et al. (2020)) . We characterize the lunisolar tidal influence on this dominantly effusive eruption which took place in the Equatorial zone, to further investigate the specific response of Fogo volcano to this permanent external forcing associated with Earth tides.

Section snippets

Fogo volcano and the 2014–2015 eruption

Fogo volcano is located on one of the dozen islands composing the Cape Verde archipelago, which lies ~450 km west of Africa, in the North Atlantic (Fig. 1). The west-open crescent formed by the islands rises on the top of a 1200 km diameter swell characterized by the largest bathymetric (+ 2 km) and geoid (+ 8 m) anomalies in the world which are thought to result from an upwelling mantle plume (Courtney and White, 1986; Grevemeyer, 1999; Carvalho et al., 2019). The rise of the Cape Verde

Retrieval of lava and SO2 emissions

Lava Volume Flow Rate (VFR) and SO2 vertical column densities (VCD) have been retrieved together from the HOTVOLC system. HOTVOLC is a Web-GIS volcano monitoring system using SEVIRI (Spinning Enhanced Visible and Infrared Imager) sensor on-board Meteosat geostationary satellite (https://hotvolc.opgc.fr) and developed at the OPGC (Observatoire de Physique du Globe de Clermont-Ferrand) in 2009 (Gouhier et al., 2016). The spectral bands of the SEVIRI sensor allow us to simultaneously characterize

Results

MSG-SEVIRI satellite images reveal a maximum of lava VFR and SO2 VCD detected between 1 and 2 days respectively, after the onset of the eruption (Fig. 2). Although the seismic tremor data does not cover the first week of the eruption, it still shows significant variations with a maximum reached on 3 December, followed by an overall slow decay. A stronger decline is observed for the SO2 VCD that drops by half in about a week and then slightly varies around an index value of 8 for the rest of the

Discussion

The Singular Spectrum Analysis applied to three geophysical time-series acquired during the 2.5-month Fogo eruption provides a new evidence of the influence of lunisolar gravitational forces on effusive eruptions. We identified between 4 and 5 tidal periodicities in the SO2, lava VFR and seismic tremor time-series with periods ranging from semi-diurnal to fortnightly (Table 1, Fig. 4). These results confirm and complement the observations made by Dumont et al. (2020) showing that the movements

Conclusion

Our study focuses on the 2014–2015 eruption of the Fogo volcano, Cape Verde. We analyze three co-eruptive geophysical time-series, namely the seismic tremor, SO2 emissions and lava volume flow rate (VFR), using the Singular Spectrum Analysis (SSA). By considering the first month of the eruptive activity, we were able to identify between 4 and 5 different tidal periods in each of these volcanological time-series, ranging from semi-diurnal to fortnightly periods. These results clearly show a

Data availability

The SO2 emission and lava volume flow rate (VFR) time-series are available from the HOTVOLC platform (https://hotvolc.opgc.fr). The l.o.d time-series is freely accessible as part of the EOP14C04 data set provided by the International Earth Rotation Service (https://www.iers.org/IERS/EN/DataProducts/EarthOrientationData/eop.html, IERS, Paris, France) as well as that of the sea level, accessible from Permanent Service for mean sea level platform (PSML, 2019). The seismic tremor data is available

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgment

The authors would like to thank E.P·S Eibl for fruitful discussion on data processing and João Fonseca for making possible the seismic mission to Fogo and its contribution to the FIRE project. The authors also thank two anonymous reviewers and Mark Jellinek, for editorial handling. SD would like to thank the Fundação para a Ciência e a Tecnologia (FCT) for his financial support through the postdoctoral grant (SFRH/BPD/17714/2016), as part of Human Capital Operating Programme (POCH) and the

References (82)

  • M.P. Golombek et al.

    Tidal triggering of seismic and volcanic phenomena during the 1879–1880 eruption of Islas Quemadas volcano in El Salvador, Central America

    J. Volcanol. Geotherm. Res.

    (1978)
  • I. Grevemeyer

    Isostatic geoid anomalies over mid-plate swells in the Central North Atlantic

    J. Geod.

    (1999)
  • Y. Guéhenneux

    Improved space borne detection of volcanic ash for real-time monitoring using 3-band method

    J. Volcanol. Geotherm. Res.

    (2015)
  • G. Jentzsch

    Mayon volcano, Philippines: some insights into stress balance

    J. Volcanol. Geotherm. Res.

    (2001)
  • J.L. Le Mouël

    On forcings of length of day changes: from 9-day to 18.6-year oscillations

    Phys. Earth Planet. Inter.

    (2019)
  • C. Leva et al.

    Mantle earthquakes beneath Fogo volcano, Cape Verde: evidence for subcrustal fracturing induced by magmatic injection

    J. Volcanol. Geotherm. Res.

    (2019)
  • F. Lopes

    The mantle rotation pole position. A solar component

    Compt. Rendus Geosci.

    (2017)
  • J. Mata

    The 2014–15 eruption and the short-term geochemical evolution of the Fogo volcano (Cape Verde): evidence for small-scale mantle heterogeneity

    Lithos

    (2017)
  • G. Patanè et al.

    Earth tides and Etnean volcanic eruptions: an attempt at correlation of the two phenomena during the 1983, 1985 and 1986 eruptions

    Phys. Earth Planet. Inter.

    (1994)
  • D. Vales

    Intraplate seismicity across the Cape Verde swell: a contribution from a temporary seismic network

    Tectonophysics

    (2014)
  • R. Vautard et al.

    Singular-spectrum analysis: a toolkit for short, noisy chaotic signals

    Physica D: Nonlinear Phenomena

    (1992)
  • I.M. Watson

    Thermal infrared remote sensing of volcanic emissions using the moderate resolution imaging spectroradiometer

    J. Volcanol. Geotherm. Res.

    (2004)
  • G. Williams-Jones

    A model of degassing and seismicity at Arenal Volcano, Costa Rica

    J. Volcanol. Geotherm. Res.

    (2001)
  • D. Zaccagnino

    Tidal modulation of plate motions

    Earth Sci. Rev.

    (2020)
  • F. Amelung et al.

    InSAR observations of the 1995 Fogo, Cape Verde, eruption: implications for the effects of collapse events upon island volcanoes

    Geophys. Res. Lett.

    (2002)
  • M. Bagnardi et al.

    High resolution digital elevation model from tri-stereo Pleiades-1 satellite imagery for lava flow volume estimates at Fogo volcano

    Geophys. Res. Lett.

    (2016)
  • R. Barrett

    Revisiting the tsunamigenic volcanic flank-collapse of Fogo Island in the Cape Verdes, offshore West Africa

    Geol. Soc. Lond. Spec. Publ.

    (2019)
  • C. Bizouard

    The IERS EOP 14C04 solution for earth orientation parameters consistent with ITRF 2014

    J. Geod.

    (2019)
  • S. Bredemeyer et al.

    Synchronous degassing patterns of the neighbouring volcanoes Llaima and Villarrica in south-central Chile: the influence of tidal forces

    Int. J. Earth Sci.

    (2014)
  • S. Calvari

    Satellite and ground remote sensing techniques to trace the hidden growth of a lava flow field: the 2014–2015 effusive eruption at Fogo volcano (Cape Verde)

    Remote Sens.

    (2018)
  • A. Cappello

    Lava flow hazard modeling during the 2014–2015 Fogo eruption, Cape Verde

    J. Geophys. Res. Solid Earth

    (2016)
  • T. Caputo

    Spectral analysis of ground thermal image temperatures: what we are learning at Solfatara volcano (Italy)

    Adv. Geosci.

    (2020)
  • B. Chouet

    Excitation of a buried magmatic pipe: a seismic source model for volcanic tremor

    J. Geophys. Res.

    (1985)
  • R.C. Courtney et al.

    Anomalous heat flow and geoid across the Cape Verde rise: evidence for dynamic support from a thermal plume in the mantle

    Geophys. J. Int.

    (1986)
  • S.I. Custodio

    Tidal modulation of seismic noise and volcanic tremor

    Geophys. Res. Lett.

    (2003)
  • E. De Lauro

    Synchronization between tides and sustained oscillations of the hydrothermal system of Campi Flegrei (Italy)

    Geochem. Geophys. Geosyst.

    (2013)
  • F. Dinger

    Periodicity in the BrO/SO2 molar ratios in the volcanic gas plume of Cotopaxi and its correlation with the Earth tides during the eruption in 2015

    Solid Earth

    (2018)
  • S.M. Dionis

    Diffuse CO2 degassing and volcanic activity at Cape Verde islands, West Africa

    Earth, Planets and Space

    (2015)
  • D. Dzurizin

    Influence of fortnightly earth tides at Kilauea volcano, Hawaii

    Geophys. Res. Lett.

    (1980)
  • E.P. Eibl

    Tremor-rich shallow dyke formation followed by silent magma flow at Bárðarbunga in Iceland

    Nat. Geosci.

    (2017)
  • B. Faria

    Monitorização Geofísica do Vulcão do Fogo e Níveis de Alerta. Ph.D thesis

    (2010)
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