Letizia Spampinato

Chronology and complex volcanic processes during the 2002--2003 flank eruption at Stromboli volcano (Italy) reconstructed from direct observations and surveys with a handheld thermal camera

[1] Effusive activity at Stromboli is uncommon, and the 2002–2003 flank eruption gave us the opportunity to observe and analyze a number of complex volcanic processes. In particular, the use of a handheld thermal camera during the eruption allowed us to monitor the volcano even in difficult weather and operating conditions. Regular helicopter-borne surveys with the thermal camera throughout the eruption have significantly improved (1) mapping of active lava flows; (2) detection of new cracks, landslide scars, and obstructions forming within and on the flanks of active craters; (3) observation of active lava flow field features, such as location of new vents, tube systems, tumuli, and hornitos; (4) identification of active vent migration along the Sciara del Fuoco; (5) monitoring of crater’s inner morphology and maximum temperature, revealing magma level changes within the feeding conduit; and (6) detection of lava flow field endogenous growth. Additionally, a new system developed by A. J. L. Harris and others has been applied to our thermal data, allowing daily calculation of effusion rate. These observations give us new insights on the mechanisms controlling the volcanic system.

The 2007 Stromboli eruption: Event chronology and effusion rates using thermal infrared data

Accepted for publication in Journal of Geophysical Research. Copyright (2009) American Geophysical Union. Further reproduction or electronic distribution is not permitted.

A total volatile inventory for Masaya Volcano, Nicaragua

NERC project “Magma dynamics at persistently degassing basaltic volcanoes: A novel approach to linking volcanic gases and magmatic volatiles within a physical model” (NE/F004222/1 and NE/F005342/1).

Lava lake surface characterization by thermal imaging: Erta 'Ale volcano (Ethiopia)

The project ‘‘Sviluppo di sistemi di monitoraggio’’ (Dipartimento di Protezione Civile di Regione Sicilia, INGV Catania Section, Italy), the Leverhulme Trust, the BBC, and the Ethiopian Air Force.

Multiparametric study of the February-April 2013 paroxysmal phase of Mt. Etna New South-East crater

European FP7 MED-SUV (MEditerranean SUpersite Volcanoes). Grant Number: 308665 European Research Council European FP7 (FP/2007-2013)/ERC. Grant Number: 279802 SIGMA (Sistema Integrato di sensori in ambiente cloud per la Gestione Multirischio Avanzata)

The unusual 28 December 2014 dike-fed paroxysm at Mount Etna: Timing and mechanism from a multidisciplinary perspective

Between 2011 and 2013, there were 43 lava fountain episodes from Mount Etnas New South-East summit crater (NSEC). In 2014, this intense activity was supplanted by sporadic Strombolian explosions and the opening of an eruptive fissure between July and August. The only lava fountaining episode of the year occurred on 28 December; this was characterized by the emplacement of a shallow dike that, at the surface, fed two distinct lava flows from an ENE-WSW trending eruptive fissure. Here we provide a detailed picture of the onset of the dike emplacement, as well as the mechanism driving its migration, using a multidisciplinary data set based on seismic, geodetic, geochemical, and volcanological observations. The dike emplacement was preceded by a pressurization of the magmatic plumbing system recorded from August 2014 on. This pressurization has been modeled as a vertically elongated magmatic source located beneath the summit craters at ~4.5 km below sea level. From September to October, magma rising was also detected by seismic and geochemical data that highlighted pressurization of the shallower portion of the plumbing system. We suggest that the 28 December 2014 dike emplacement resulted from a modification of the preexisting NSEC shallow plumbing system, largely due to drainage of the main shallow conduit during the July–August 2014 eruptive fissure activity. Such a structural modification might have created the conditions for magma emplacement as a dike-like structure.

The 5 April 2003 Explosion of Stromboli: Timing of Eruption Dynamics Using Thermal Data

Strombolis 5 April 2003 explosion sent an ash plume to 4 km and blocks to 2 km, representing one of the most powerful events over the past 100 years. A thermal sensor 450 m east of the vent and a helicopter-flown thermal camera captured the event dynamics allowing detailed reconstruction. This review links previous studies providing a complete collation and clarification of the actual event chronology, while showing how relatively inexpensive thermal sensors can be used to provide great insight into processes that cannot be observed from locations outside the eruption cloud. The eruption progressed through four phases, comprised 29 discrete explosions, and lasted 373 s. The opening phase (phase 1) comprised ∼30 s of precursory ash emission, with stronger emission beginning after 17 s. This was abruptly terminated by the main blast of phase 2 that comprised emission of a rapidly expanding ash cloud followed, after 0.4 s, by a powerful jet with velocities of up to 320 m/s. A second explosive phase (phase 3) began 38 s later and involved ascent of a phoenix cloud and explosive emission above a lateral vent lasting 75 s. This was followed by a 175-s-long phase of weaker, pulsed emission. The eruption was terminated by a series of three explosions (phase 4) sending ash to ∼600 m at velocities of 27―45 m/s and lasting 87 s. Together, these results have shown that a low-energy opening phase was followed by the highest-energy phase. Each phase itself comprised groups of discrete explosions, with energy of the explosions diminishing during the two final phases.

The 7 September 2008 Vulcanian explosion at Stromboli volcano: Multiparametric characterization of the event and quantification of the ejecta

This paper was partially supported by a research project (project INGV-DPC Paroxysm V2/03, 2007–2009) funded by Istituto Nazionale di Geofisica e Vulcanologia and by the Italian Civil Protection.

The eruptive activity of 28 and 29 December 2002

At 1820 UT of 28 December 2002, an eruptive vent opened on the NE flank of the Sciara del Fuoco (SdF) at 600 m above sea level, marking the onset of the 2002–2003 eruptive crisis of Stromboli volcano. The first eruptive hours were characterized by mild spattering and effusive activity from the new vent and the summit vent at crater 1. Gravitational instability processes also determined the partial collapse of NE walls of the summit cone (crater 1). Pyroclastic material partly accumulated on the NE part of the SdF and partly flowed downslope and reached the sea at Spiaggia dei Gabbiani, forming a ~4-m-thick, reddish avalanche, that was soon covered by a lava flow emitted in the following hours. In this paper, we describe the first hours of activity through eyewitnesses’ reports, geophysical monitoring, field and laboratory studies, of the erupted pyroclastic material and lava flows. Daily temperature measurements were carried out on the avalanche deposit formed by the flow of scoria along the SdF, using a handheld thermal camera mainly during helicopter surveys. A fast cooling rate was typical of the deposit surface, and a slow cooling rate was representative of its inner portion.

Monitoring active volcanoes using a handheld thermal camera

Thermal imaging has recently been introduced in volcanology to analyse a number of different volcanic processes. This system allows us to detect magma movements within the summit conduits of active volcanoes, and then to reveal volcanic activity within the craters even through the thick curtain of gases usually released by volcanoes such as Mt Etna and Stromboli. Thermal mapping is essential during effusive eruptions, since it distinguishes lava flows of different age and concealed lava tubes’ path, improving hazard evaluation. Recently, thermal imaging has also been applied to reveal failure planes and instability on the flanks of active volcanoes. Excellent results have been obtained in terms of volcanic prediction during the two recent eruptions of Mt Etna and Stromboli, both occurred in 2002-2003. On Etna, thermal images monthly recorded on the summit of the volcano revealed the opening of fissure systems several months in advance. After the onset of the flank eruption, daily thermal mapping allowed us to monitor a complex lava flow field spreading within a forest, below a thick plume of ash and gas. At Stromboli, helicopter-borne thermal surveys allowed us to recognise the opening of fractures along the Sciara del Fuoco, one hour before the large failure that caused severe destruction on the island on 30 December 2002. This was the first time ever that volcanic flank collapse has been monitored with a thermal camera. In addition, we could follow the exceptional explosive event of the 5th April 2003 at Stromboli from helicopter with a thermal camera recording images immediately before, during and after the huge explosion. We believe that a more extended use of thermal cameras in volcano monitoring, both on the ground and from fixed positions, will significantly improve our understanding of volcanic phenomena and hazard evaluations during volcanic crisis.