# The 2014 Effusive Eruption at Stromboli: New Insights from In Situ and Remote-Sensing Measurements
## 1 Introduction  
Stromboli volcano (Italy; Figure 1), a stratovolcano located at the easternmost end of the Aeolian Archipelago, experienced a flank eruption from August-November 2014 [1; 2; 3; 4; 5; 6; 7]. In this paper, in situ and remote-sensing measurements at Stromboli between May and November 2014 are presented. Data comprise videos recorded by the visible and infrared cameras network [8; 9] (Figure 1a), ground displacement recorded by the permanent sited Ku-band, Ground-Based Interferometric Synthetic Aperture Radar (GBInSAR) device [10; 11], ground displacements in the seismic band (0.02-10 Hz) [12; 13] (Figure 1a), and high-resolution Digital Elevation Models (DEMs) reconstructed based on tri-stereo PLEIADES-1 imagery and Light Detection and Ranging (LiDAR) data, respectively. Data allowed us to characterize the precursors and the phenomena that occurred during the eruption, as well as an estimation of the erupted volume.  
Stromboli is characterized by persistent Strombolian activity from several vents within a crater terrace area [9; 14] (Figure 1b). The volcanic edifice is frequently affected by landslides [15], mainly within the Sciara del Fuoco (SdF; Figure 1b), a collapse depression on the NW flank of the island formed during the last 13 ka [16; 17]. Landslides triggered tsunamis on average every 20 years [18], especially during flank eruptions or paroxysmal explosions [12; 19; 20]. Small to large volcano slope instability characterized the initial phases of the last four flank eruptions (1985-86, 2002-03, 2007, 2014) [21; 22; 23; 24], triggering tsunamis only during the 2002-03 event [22; 25].  
The last flank eruption started at Stromboli on 7 August 2014, preceded by 2 months of increased Strombolian activity and several lava overflows from the craters expanding along the SdF [2; 26]. Overflows were often accompanied by landslides along the SdF [7], described as rock-falls and/or gravel slides, evolving down slope to gravel flows (Figure 2a). The onset of the 2014 flank eruption (6-7 August) involved the breaching of the summit cone with emplacement of a landslide along the SdF (Figure 2b), the opening of an eruptive fissure on the NE flank of the cone [24], and the effusion of lava from the crater rim at first and from the eruptive fissure later, feeding the 2014 lava flow field [4; 5; 7]. The eruption was characterized by the lava effusion in the SdF from a fissure at 650 m above sea level (a.s.l.) that lasted until 13 November 2014 [4].  
The 2014 lava flow field was similar to others erupted from high-elevation vents (as described for the 2002-2003 lava flow field by [27]), comprising: (i) a series of tumuli and lava flows around the effusive vent at \(\sim\)650 m a.s.l. (proximal shield); (ii) a medial zone fed by small flows, and characterized by frequent lava crumbling down slope and producing a debris field; (iii) a basal toe composed of the debris flow field emplaced above the stacked lava delta [28]. The erupted volume has been estimated to be 7.4 \(\times\) 10\({}^{6}\) m\({}^{3}\) by [4] and \(\sim\)5.5 \(\times\) 10\({}^{6}\) m\({}^{3}\) by [5].