Global distribution of open-vent volcanoes, listed in Supplementary table S1, encompassing a broad range of magma compositions and tectonic settings. Superscript 1: Average SO 2 flux (2005-2015) from Carn et al. (2017)

Global distribution of open-vent volcanoes, listed in Supplementary table S1, encompassing a broad range of magma compositions and tectonic settings. Superscript 1: Average SO 2 flux (2005-2015) from Carn et al. (2017)

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Open-vent, persistently degassing volcanoes—such as Stromboli and Etna (Italy), Villarrica (Chile), Bagana and Manam (Papua New Guinea), Fuego and Pacaya (Guatemala) volcanoes—produce high gas fluxes and infrequent violent strombolian or ‘paroxysmal’ eruptions that erupt very little magma. Here we draw on examples of open-vent volcanic systems to h...

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... 2013; Vergniolle and Métrich 2021). Many are well studied because persistent low-level activity allows access and collection of extended time series of monitoring data. Open-vent volcanoes are found in all tectonic settings and are associated with a range of magma compositions and bulk viscosities (some examples-not an exhaustive listare shown in Fig. 1 and Table S1). Open-vent volcanoes may be active over millennia-for example Masaya, Nicaragua (Stix 2007), Stromboli, Italy ( Allard et al. 1994), Etna, Italy (Allard 1997), Villarrica, Chile ( Witter et al. 2004), Yasur Volcano, Vanuatu ( Métrich et al. 2011) and Erebus, Antarctica ( Oppenheimer et al. 2011)-or years to decades, such ...
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... that persistent, or passive, degassing accounts for ~ 90% of the global outgassing sulphur flux from volcanoes ( Carn et al. 2016;Carn et al. 2017) and that most of the top 20 volcanic outgassers, as quantified from UV sensors total ozone mapping spectrometer (TOMS) and ozone mapping instrument (OMI), may be classified as 'open-vent' (Table S1; Fig. 1) (Carn et al. ...
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... magma and μ a is the viscosity of ascending magma. If no magma is erupted, then Q ascend must be balanced by the volume flux of descending magma minus the volume of the volatiles released to the surface (1) (Kazahaya et al. 1994;Stevenson and Blake 1998). SO 2 fluxes of 10 2 -10 3 tonnes per day (typical of many of the volcanoes highlighted in Fig. 1 and table S1), for example require magma fluxes in the conduit of ~ 1-10 m 3 /s. Magma flux, in turn, is controlled by the conduit radius (assuming a cylindrical geometry) and the flow velocity, which is a function of magma viscosity and density. If the gas is transported with the magma, maintaining the same gas supply (assuming ...
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... fluxes from open-vent volcanoes are decoupled from eruptions Recent observations of volcanic outgassing from space have highlighted the number and diversity of open-vent volcanoes that emit the overwhelming bulk of volcanic gases into the atmosphere every year ( Fig. 1; Table S1). Global satellitebased monitoring of volcanic gas emissions demonstrate unequivocally that > 90% of the global outgassing fluxes of sulphur dioxide are produced during 'passive degassing' from an open-vent, where no eruption is taking place (Carn et al. 2017;Fioletov et al. 2016;Werner et al. 2019). These open-vent volcanoes ...
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... volcanoes that generate high outgassing fluxes (Fig. 1) are often located in regions of complex tectonics and local extension. The correspondence between the locations of open-vent volcanoes and major crustal extensional structures highlights the role of tectonics in promoting magma intrusion, MVP segregation and MVP migration to the surface. Although the processes that modulate MVP ...
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... located at the boundary between a compressional and extensional regime in the Hebrides Arc. c Mount Etna, Italy, is located in an extension region stretching from Eastern Sicily to the south of Italy (see text for detail). Maps were generated using GeoMapApp Nicaraguan graben-that contains Lake Nicaragua and Lake Managua ( Morgan et al. 2008) ( Fig. 1; 9a). Masaya exhibits cycles of intense outgassing that coincide with lava lake activity ( Delmelle et al. 1999;Stoiber et al. 1986) ( Delmelle et al. 1999;Stoiber et al. 1986) but few eruptions-there has been no major effusive activity since 1965 (Harris 2009)-although Masaya has a history of large basaltic Plinian eruptions (at 6 ka, 2.1 ...
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... a top-ranking volcanic open-vent outgasser (Figs. 1 and 4) located in the New Hebrides arc (Fig. 9b), is situated in the transition zone between a compressional regime in the central arc (Calmant et al. 2003) and an extensional regime in the south ( Beier et al. 2018). The relative motion between the central and neighbouring northern and southern arc segments, respectively, is accommodated by dextral strike-slip zones (Pelletier et al. 1998). ...
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... basalt-dominated open-vent volcanoes ( Fig. 10a) with basalt or alkali basalt lava lakes or open vents (e.g. Stromboli, Yasur, Villarrica, Masaya, Fuego), volatiles may be delivered to the atmosphere through a combination of deep and shallow mechanisms, both consistent with the volcanic a At basalt-dominated volcanoes, magmas rise to shallow storage regions in the crust to form ...
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... intermediate composition open-vent volcanoes (dominated by andesites and dacites) (Fig. 10b) (e.g. Bagana, Soufrière Hills, Santiaguito, Anatahan), magma crystallisation over long timescales generates extensive regions of mush. The crystallisation of basalts at lower crustal depths may generate low viscosity hydrous or even 'superhydrous' basaltic andesite or andesite melts, as inferred for Kamchatka ( Goltz et al. 2020). ...

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... The magma source is an open-system shallow magma reservoir at a depth of 5-8 km that is compositionally and thermally buffered by the nearly-continuous recharge of homogeneous magmas (Brenna et al. 2022) despite overlapping compositions between the calderaforming welded ignimbrite and underlying tephra (Yuen et al. 2022). The magma reservoir can be supplemented by a small amount of homogenised melt; as it crystallises, volatility builds up in the magma (Edmonds et al. 2022). These volatile substances may have contributed to magma overpressure (Geshi et al. 2022), causing intracaldera eruptions to maintain an equilibrium until sufficient volatile substances were concentrated in the Hunga Tonga and Hunga Ha'apai magma reservoirs by an M 5.8 earthquake (Fig. 5) for release on 15 January 2022. ...
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Background On 15 January 2022, a submarine volcanic eruption occurred at Hunga Tonga. Time-series monitoring from the Geostationary Operational Environmental Satellite (GOES-17) was analysed to estimate the magnitude, location, start time, and duration of the eruption and to measure the evolving characteristics of Hunga Ha’apai Island. Results The eruption starting time was between 04:10 and 04:20 UTC with an eruption intensity that increased drastically and produced a plume that reached a maximum height of about 58 km. The explosive phase lasted 13 h and consisted of multiple steam and tephra explosions with an M 5.8 earthquake. The Airmass RGB, which combines water vapor and infrared imagery from the ABI and was used to monitor the evolution of the volcano, captured a plume of gases from the eruption of Hunga Tonga volcano on 15 January 2022. This type of imagery provides information on the middle and upper levels of the troposphere and distinguishes between high- and mid-level clouds. Conclusion A sonic explosion also occurred, possibly when the volcano collapsed underwater and seawater rushed in, causing a huge displacement of seawater. The Hunga Tonga–Hunga Ha’apai eruption is not over and could worsen in the coming days. Future studies are required to assess the potential effects on stratospheric chemistry and radiation for secondary damage analysis.
... Larger contents of heavy crystals such as olivine and pyroxene add to the density excess by more mafic magmas. However, shallow magmas get degassed as a reflection of the largely dominant role of pressure on volatile saturation, as can be inferred from measuring gas emissions at quiescent volcanoes or fumaroles (Aiuppa et al., 2019;Burgisser & Degruyter, 2015;Edmonds et al., 2022). At shallow crustal depths, magmas tend to stall and evolve in composition toward more felsic, water-richer, less dense melt phases than basaltic magmas. ...
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Active magma chambers are periodically replenished upon a combination of buoyancy and pressure forces driving upward motion of initially deep magma. Such periodic replenishments concur to determine the chemical evolution of shallow magmas, they are often associated to volcanic unrests, and they are nearly ubiquitously found to shortly precede a volcanic eruption. Here, we numerically simulate the dynamics of shallow magma chamber replenishment by systematically investigating the roles of buoyancy and pressure forces, from pure buoyancy to pure pressure conditions and across combinations of them. Our numerical results refer to volcanic systems that are not frequently erupting, for which magma at shallow level is isolated from the surface (“closed conduit” volcanoes). The results depict a variety of dynamic evolutions, with the pure buoyant end‐member associated with effective convection and mixing and generation of no or negative overpressure in the shallow chamber, and the pure pressure end‐member translating into effective shallow pressure increase without any dynamics of magma convection associated. Mixed conditions with variable extents of buoyancy and pressure forces illustrate dynamics initially dominated by overpressure, then, over the longer term, by buoyancy forces. Results globally suggest that many shallow magmatic systems may evolve during their lifetime under the control of buoyancy forces, likely triggered by shallow magma degassing. That naturally leads to long‐term stable dynamic conditions characterized by periodic replenishments of shallow partially degassed, heavier magma by volatile‐rich fresh deep magma, similar to those reconstructed from petrology of many shallow‐emplaced magmatic bodies.
... In this respect, experimental petrology may provide further clues as to the drivers of such paroxysmal events, as well as textural studies focused on ascent rates and diffusion chronometry. Moreover, monitoring of gas emissions might provide key precursory signals for future paroxysmal events (Aiuppa et al. 2007;Burton et al. 2007;Allard 2010;Aiuppa et al. 2017;Edmonds et al. 2022). ...
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Villarrica (35.9°S; 2,847 m a.s.l.) is one of the most active volcanoes in South America and is the highest risk volcano in Chile. It has an open conduit with a persistent lava lake. On the 3 March 2015, Strombolian activity rapidly progressed into a 1.5 km-high lava fountain, erupting at least ∼2.4 × 106 m3 of tephra. Soon after, the activity returned to mild Strombolian “background” explosions, which lasted until early 2017. Understanding the pre-eruptive conditions of such paroxysmal events is fundamental for volcanic hazard assessment. We present major and trace element geochemistry for glass and crystalline phases of basaltic andesite paroxysm pyroclasts (52–56 wt.% SiO2), and for the subsequent Strombolian “background” activity through February 2017 (54–56 wt.% SiO2). The lava fountain source magma was initially stored in a deeper and hotter region (9.4–16.3 km; ca. 1140oC) and was then resident in a shallow (≤0.8 km) storage zone pre-eruption. During storage, crystallising phases comprised plagioclase (An66–86), olivine (Fo75–78) and augite (En46–47). Equilibrium crystallisation occurred during upper-crustal magmatic ascent. During storage in the shallower region, magma reached H2O saturation, promoting volatile exsolution and over-pressurization, which triggered the eruption. In contrast, subsequent “background” explosions involving basaltic-andesite were sourced from a depth of ≤5.3 km (ca. 1110 oC). Pre-eruptive conditions for the 2015 lava fountain contrast with historical 20th century eruptions at Villarrica, which were likely driven by magma that underwent a longer period of mixing to feed both effusive and explosive activity. The rapid transition to lava fountaining activity in 2015 represents a challenging condition in terms of volcano monitoring and eruption forecasting. However, our petrological study of the pyroclastic materials erupted in 2015 offers significant insights into eruptive processes involving this type of eruption. This aids in deciphering the mechanisms behind sudden eruptions at open conduit systems.
... Conversely, low Vp/Vs values are associated with a relevant presence of gas within the rock body (e.g., Ref. 44 ). In fact, a medium saturated with gas behaves as a sponge and thus has a low compression modulus that causes low P-wave velocity values, whereas the decrease in S-wave velocity is not as substantial, determining a low Vp/Vs ratio 8,45 . Thus, it is widely believed that low Vp and low Vp/Vs anomalies are indicative of a gas-filled porous medium [46][47][48] . ...
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Seismic tomography is a very powerful and effective approach to look at depths beneath volcanic systems thus helping to better understand their behaviour. The P-wave and S-wave velocity ratio, in particular, is a key parameter useful to discriminate the presence of gas, fluids and melts. We computed the first 3-D overall model of Vp, Vs and Vp/Vs for the Lipari–Vulcano complex, central sector of the Aeolian volcanic archipelago (southern Italy). The investigated area has been characterized in recent times by fumaroles, hydrothermal activity and active degassing. In particular, in the Vulcano Island, several episodes of anomalous increases of fumarole temperature and strong degassing have been recorded in the past decades and the last “crisis”, started in September 2021, is still ongoing. For tomographic inversion we collected ~ 4400 crustal earthquakes that occurred in the last thirty years and we used the LOcal TOmography Software LOTOS. The results clearly depicted two low Vp and Vp/Vs anomalies located up to ~ 8 km depths below Vulcano and the western offshore of Lipari, respectively. These anomalies can be associated to the large presence of gas and they furnish a first picture of the gas-filled volumes feeding the main degassing activity of the area.
... Open-vent volcanoes provide a window into their underlying magmatic system that allows detailed investigation of magmatic processes driving their activity and behavior. Such systems are typically characterized by mild explosive activity and persistent gas emissions (Rose et al., 2013;Vergniolle and Métrich, 2021;Edmonds et al., 2022), making them an ideal place to develop and test monitoring techniques. However, open-vent volcanoes usually degas directly from their magmatic system. ...
Article
Erebus volcano on Ross Island in Antarctica is an iconic open-vent volcano that has hosted a convecting anorthoclase-rich phonolite lava lake for at least 50 years. Recent magnetotelluric observations have imaged a conduit system originating at least 60 km below Erebus. This terminates in a seismically-imaged shallow magma reservoir about 500 m NW of the crater with an upper surface at about 500 m depth. A narrow and inclined terminal conduit system connects the shallow reservoir to the lava lake. Bomb-ejecting Strombolian eruptions from the lava lake and sporadically active adjacent vents are common. Larger eruptive activity with locally substantially elevated hazard has also been observed, including exceptionally energetic Strombolian activity in 1984 and an Inner Crater phreatic explosion in 1993. Despite sustained degassing and frequent eruptions, geochemical data show the composition of the lava has remained stable for the last 17 ka, consistent with the long-lived transcrustal magmatic system underlying the lake. Global Navigation Satellite System (GNSS) data collection on Ross Island began in the late 1990s with campaign observations. In the early 2000s, additional benchmarks were added closer to the summit of Erebus and continuous GNSS (cGNSS) sites were co-located with a seismic network. Today, seven cGNSS sites operate on the summit plateau and flanks of the volcano, and a network of eight campaign benchmarks has been surveyed episodically. We present the first comprehensive geodetic data analysis and modeling results integrating these more than two decades of data collected at Erebus. We resolve long-term subsidence of Ross Island, which a simple viscoelastic model links to the long-term growth of Erebus over the last 20 ka. The data also show multi-year cycles of inflation and deflation in the summit area, consistent with activity in the shallow summit magmatic system. These small amplitude (several mm/yr) transient dynamics suggest multi-year pulses of pressurization and depressurization, or geometric changes within the shallow magmatic system that we can reproduce with analytical source models. The most recent inflation pulse lasted from November 2020 until March 2022 when several stations moved radially away from the shallow magmatic system and upwards at 10–15 mm/yr. Based on prior cycles, this deformation may result in increased eruptive active suggesting that continued and enhanced surveillance of Erebus is warranted. These observations contrast with the long-term general stability of the lava lake, but reflect Inner Crater dynamics, which can include changes in lava lake elevation and associated topographic changes of over 20 m on multi-year time scales. Our results emphasize the value of long-term and campaign-aided high-accuracy GNSS observations at open-vent volcanoes. This is especially true for volcanoes like Erebus which are remote and may only be accessible for a few months a year, and that deform at amplitudes and periods that may be difficult to resolve with satellite-based radar.
... The theoretical magmatic gas compositions coexisting in equilibrium with the modelled melts-for all melt compositions explored-evolve from being CO 2 -rich at initial pressures (300 to 50-40 MPa, depending on the runs) to H 2 O-and S-rich at 0.1 MPa (Fig. 4b, Supplementary Fig. 4), reflecting the pressuredependent solubilities of the major volatile species in silicate melts 64,65 . This compositional evolution is reflected in the decreasing CO 2 /S T ratio in the fluid phase with decreasing pressure (Fig. 6c). ...
... If, as the above modelling suggests, fumarolic emissions from the October-November 2021 degassing unrest are indeed prevalently magmatic, then their CO 2 /S T ratio-at least that of the H 2 O-poorest samples, in which the magmatic gas proportion is estimated to be >80%-can be used to infer the pressure of final gas-melt equilibration (i.e., the pressure at which gas separates from melt) based on the distinct pressure-dependent solubilities of the major volatile species in silicate melts [64][65][66] . We show how the CO 2 /S T ratio in the exsolved fluid phase is predicted to vary as a function of pressure, for the various model starting conditions for La Fossa (Fig. 6c). ...
... To reconcile geophysical observations with geochemical evidence, a plumbing system model has been proposed 23 in which temporal changes in magmatic gas composition are explained by time-varying gas contributions from multiple stationary, compositionally-distinct magma storage reservoirs, located at various depths within the vertically-elongated La Fossa plumbing system (Fig. 6a). In this stationary magma scenario, degassing unrest reflects gas accumulation in the roof zone of a magma reservoir (with gas bubble deriving from deeper in the magmatic system, and/or through exsolution driven by cooling and crystallisation 65,79 ), until such a time as this volatile-rich cap is destabilised, either by some external forcing or once some threshold pressure is reached. Following this, accumulated fluids are released abruptly and ascend through the shallow magmatichydrothermal system, causing unrest 23 . ...
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The benign fuming activity of dormant volcanoes is punctuated by phases of escalating degassing activity that, on some occasions, ultimately prelude to eruption. However, understanding the drivers of such unrest is complicated by complex interplay between magmatic and hydrothermal processes. Some of the most comprehensively characterised degassing unrest have recently been observed at La Fossa cone on Vulcano Island, but whether or not these episodes involve new, volatile-rich ascending magma remains debated. Here, we use volcanic gas measurements, in combination with melt inclusion information, to propose that heightened sulphur dioxide flux during the intense fall 2021 La Fossa unrest is sourced by degassing of volatile-rich mafic magma. Calculations using a numerical model indicate observations are consistent with the unrest being triggered by the emplacement of ∼3·10⁶ m³ of mafic magma at ∼4–5 km depth. Degassing of mafic magma is argued as a recurrent driver of unrest at dormant volcanoes worldwide.
... While recent models have focused extensively on extrusive outgassing (e.g., Dorn et al., 2018;Grott et al., 2011;Kite et al., 2009;Noack et al., 2017;Ortenzi et al., 2020), intrusive volatile release is often neglected when estimating the outgassing fluxes of early atmospheres. However, there are some studies addressing the topic of intrusive volatile release (e.g., Degruyter et al., 2019;Edmonds et al., 2022;McKay et al., 2014;Nava et al., 2021;Parmigiani et al., 2017). McKay et al. (2014) and Nava et al. (2021) attempted to match proxies of climate changes coinciding with large igneous provinces (LIPs) by considering the impact of intrusive outgassing. ...
... Although their activity is persistent and relatively constant in the long-term, they frequently undergo short-term variations in activity and/or eruptive style in the short-term (cf. Vergniolle and Métrich 2021;Edmonds et al. 2022). A number of studies have highlighted the sensitivity of open-vent systems to external perturbations in their magmatic system (Patanè et al. 2007;Sottili and Palladino 2012;Carey et al. 2012;Eychenne et al. 2015). ...
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Volcanoes switching from quiescence to eruption shortly after catastrophic earthquakes have raised interest for volcanic triggering and the influence of earthquakes on volcanic activity. Its influence on already active systems and especially at open-vent volcanoes is more difficult to apprehend. A number of recent observations suggest an influence of tectonic earthquakes on Popocatépetl’s activity, the importance of which remains unknown. To further investigate this, we introduce an index, based on the near-field concept, identifying the earthquakes with the highest potential to promote volcanic activity (hereafter termed “significant earthquakes”). The time series of significant earthquakes is compared with the intensity of the volcanic activity, as characterized by the number and energy of volcano-tectonic earthquakes, the number of dome extrusions, the intensity of thermal and degassing fluxes, and ash production. Three main periods with contrasting activity stand out showing that Popocatépetl presents intense activity when significant tectonic earthquakes are frequent. Enhanced extrusion apparently follows significant earthquakes quickly with pulses of dome extrusion that peak after 1.3 ± 0.3 years. Conversely, extrusive activity vanishes when significant seismicity disappears, as during the period 2003–2011, which coincides with a 12-year-long significant seismicity gap. Hence, we propose that the 1994–2022 open-vent activity at Popocatépetl is in part modulated by the repetitive occurrence of significant earthquakes that periodically promote volcanic activity.
... Harris 2008;Miwa et al. 2013;Scharff et al. 2014), (ii) the degassing and outgassing balance and its implications for understanding and modelling the magma feeding system (e.g. Aiuppa et al. 2010;Beckett et al. 2014;Edmonds et al. 2022) and (iii) transitions and controls on explosive-effusive volcanic eruption styles (e.g. Woods and Koyaguchi 1994;Ripepe et al. 2005;Cassidy et al. 2018). ...
... Head and Wilson 1989;Vergniolle and Mangan 2000;Calvari et al. 2005). While magma convection may operate in low-viscosity basaltic systems, this mechanism may not be important in more evolved volcanic systems, due to the extensive degassing-induced crystallisation in the conduit (Edmonds et al. 2022). Further research and modelling is needed to better constrain the properties and dynamics of the so called "lava pool" and the conduit at Arenal. ...
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On 29 July 1968, there was a violent reactivation of Arenal volcano. The resulting westward-directed lateral blast eruption left two villages destroyed and 78 people dead. The activity continued as a long-lasting, open-vent eruption that evolved into seven recognisable phases reflecting changes in magma supply, explosive activity and cone evolution, and ended in October 2010. Here, we review this activity, the geophysical approaches applied to understanding it and the open questions resulting from these insights. The eruptive dynamics were characterised by almost constant lava effusion, degassing, strombolian and vulcanian explosions and infrequent pyroclastic density currents. In this study, the total rock dense equivalent volume of lava and tephra erupted is calculated at 757 ± 77 Mm ³ , while the volume of the lava flow field is 527 ± 58 Mm ³ . Typical seismic activity included harmonic and spasmodic tremors, long-period events and explosion signals with frequent audible “booms”. The decline of the eruptive activity started in 2000, with a decrease in the number and size of explosive events, a shift from long to short lava flows along with the collapse of lava flow fronts and the subsequent formation of downward-rolling lava block aprons, the frequent growth of dome-like structures on the summit and a gradual decrease in seismic energy. Multiple geological and geophysical studies during this 42-year-long period of open-vent activity at Arenal resulted in many advances in understanding the dynamics of andesitic blocky lava flows, the origin and diversity of pyroclastic density currents and seismic sources, as well as the role of site effects and rough topography in modifying the seismic wavefield. The acoustic measurements presented here include two types of events: typical explosions and small pressure transients. Features of the latter type are not usually observed at volcanoes with intermediate to evolved magma composition. Explosions have different waveforms and larger gas volumes than pressure transients, both types being associated with active and passive degassing, respectively. This body of data, results and knowledge can inform on the type of activity, and associated geophysical signals, of open-vent systems that are active for decades.
... As posited by Brenna et al. (2022), caldera-forming events at HTHH may be immediately triggered by mafic recharge. In between these large-scale events, the magma reservoir may be replenished by small amounts of well-homogenized melt, and volatiles accumulates in the magma as it crystallizes (Blake, 1984;Edmonds et al., 2022). These volatiles likely contributed to magmatic overpressure, triggering small, intra-caldera eruptions to maintain an equilibrium until sufficient volatiles had been concentrated to prime the HTHH magma reservoir (Caulfield et al., 2011;Edmonds et al., 2022;Geshi et al., 2022) for the paroxysmal January 15, 2022 eruption. ...
... In between these large-scale events, the magma reservoir may be replenished by small amounts of well-homogenized melt, and volatiles accumulates in the magma as it crystallizes (Blake, 1984;Edmonds et al., 2022). These volatiles likely contributed to magmatic overpressure, triggering small, intra-caldera eruptions to maintain an equilibrium until sufficient volatiles had been concentrated to prime the HTHH magma reservoir (Caulfield et al., 2011;Edmonds et al., 2022;Geshi et al., 2022) for the paroxysmal January 15, 2022 eruption. Preliminary analyses of ashfall collected on January 15, 2022 suggest that an influx of volatile-saturated mafic magma had recently recharged the HTHH system, possibly triggering this paroxysmal event (Witze, 2022). ...
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We present a narrative of the eruptive events culminating in the cataclysmic 15 January 2022 eruption of Hunga Tonga-Hunga Ha’apai Volcano by synthesizing diverse preliminary seismic, volcanological, sound wave, and lightning data available within the first few weeks after the eruption occurred. The first hour of eruptive activity produced fast-propagating tsunami waves, long-period seismic waves, loud audible sound waves, infrasonic waves, exceptionally intense volcanic lightning and an unsteady volcanic plume that transiently reached—at 58 km—the Earth’s mesosphere. Energetic seismic signals were recorded worldwide and the globally stacked seismogram showed episodic seismic events within the most intense periods of phreatoplinian activity, and they correlated well with the infrasound pressure waveform recorded in Fiji. Gravity wave signals were strong enough to be observed over the entire planet in just the first few hours, with some circling the Earth multiple times subsequently. These large-amplitude, long-wavelength atmospheric disturbances come from the Earth’s atmosphere being forced by the magmatic mixture of tephra, melt and gasses emitted by the unsteady but quasi-continuous eruption from 0402±1—1800 UTC on 15 January 2022. Atmospheric forcing lasted much longer than rupturing from large earthquakes recorded on modern instruments, producing a type of shock wave that originated from the interaction between compressed air and ambient (wavy) sea surface. This scenario differs from conventional ideas of earthquake slip, landslides, or caldera collapse-generated tsunami waves because of the enormous (~1000x) volumetric change due to the supercritical nature of volatiles associated with the hot, volatile-rich phreatoplinian plume. The time series of plume altitude can be translated to volumetric discharge and mass flow rate. For an eruption duration of ~12 hours, the eruptive volume and mass are estimated at 1.9 km3 and ~2,900 Tg, respectively, corresponding to a VEI of 5-6 for this event. The high frequency and intensity of lightning was enhanced by the production of fine ash due to magma—seawater interaction with concomitant high charge per unit mass and the high pre-eruptive concentration of dissolved volatiles. Analysis of lightning flash frequencies provides a rapid metric for plume activity and eruption magnitude. Many aspects of this eruption await further investigation by multidisciplinary teams. It represents a unique opportunity for fundamental research regarding the complex, non-linear behavior of high energetic volcanic eruptions and attendant phenomena, with critical implications for hazard mitigation, volcano forecasting, and first-response efforts in future disasters.