Tracking morphological changes and slope instability using spaceborne and ground-based SAR data

Abstract

Stromboli (Aeolian Archipelago, Italy) is an active volcano that is frequently affected by moderate to large mass wasting, which has occasionally triggered tsunamis. With the aim of understanding the relationship between the geomorphologic evolution and slope instability of Stromboli, remote sensing information from space-born Synthetic Aperture Radar (SAR) change detection and interferometry (InSAR) and Ground Based InSAR (GBInSAR) was compared with field observations and morphological analyses. Ground reflectivity and SqueeSARâ\u84¢ (an InSAR algorithm for surface deformation monitoring) displacement measurements from X-band COSMO-SkyMed satellites (CSK) were analysed together with displacement measurements from a permanent-sited, Ku-band GBInSAR system. Remote sensing results were compared with a preliminary morphological analysis of the Sciara del Fuoco (SdF) steep volcanic flank, which was carried out using a high-resolution Digital Elevation Model (DEM). Finally, field observations, supported by infrared thermographic surveys (IRT), allowed the interpretation and validation of remote sensing data. The analysis of the entire dataset (collected between January 2010 and December 2014) covers a period characterized by a low intensity of Strombolian activity. This period was punctuated by the occurrence of lava overflows, occurring from the crater terrace evolving downslope toward SdF, and flank eruptions, such as the 2014 event. The amplitude of the CSK images collected between February 22nd, 2010, and December 18th, 2014, highlights that during periods characterized by low-intensity Strombolian activity, the production of materials ejected from the crater terrace towards the SdF is generally low, and erosion is the prevailing process mainly affecting the central sector of the SdF. CSK-SqueeSARâ\u84¢ and GBInSAR data allowed the identification of low displacements in the SdF, except for high displacement rates (up to 1.5 mm/h) that were measured following both lava delta formation after the 2007 eruption and the lava overflows of 2010 and 2011. After the emplacement of the 2014 lava field, high displacements in the central and northern portions of the SdF were recorded by the GBInSAR device, whereas the spaceborne data were unable to detect these rapid movements. A comparison between IRT images and GBInSAR-derived displacement maps acquired during the same time interval revealed that the observed displacements along the SdF were related to the crumbling of newly emplaced 2014 lava and of its external breccia. Detected slope instability after the 2014 flank eruption was related to lava accumulation on the SdF and to the difference in the material underlying the 2014 lava flow: i) lava flows and breccia layers related to the 2002â\u80\u9303 and 2007 lava flow fields in the northern SdF sector and ii) loose volcaniclastic deposits in the central part of the SdF. This work emphasizes the importance of smart integration of spaceborne, SAR-derived hazard information with permanent-sited, operational monitoring by GBI...

The 2014 Effusive Eruption at Stromboli: New Insights from In Situ and Remote-Sensing Measurements

“…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.…”

“…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].…”

Using Conceptual Models to Relate Multiparameter Satellite Data to Subsurface Volcanic Processes in Latin America

“…Although our study focused on using satellite data to identify unrest mechanisms, combining satellite‐ and ground‐based data in future studies will provide a more accurate understanding of unrest and classifications into unrest mechanisms (e.g., Di Traglia et al, ; McCormick et al, ; Muller et al, ). In short, in order to fully identify volcanic behavior, every aspect of unrest must be considered.…”

Landslide Event on 24 June in Sichuan Province, China: Preliminary Investigation and Analysis

“…In addition, a secondary landslide hit the disaster site at 11 a.m. on 27 June 2017. Fortunately, the displacement was monitored by a slope synthetic aperture radar (S-SAR) [36,37,41], and the operators ordered an evacuation prior to the landslide event, resulting in no further casualties. The rescue lasted about a week, with 3 people rescued and 10 bodies recovered.…”

“…Displacement monitoring is another important technique for EWSs [35]. GPS and InSAR combined with GIS can be applied to a wide range range of displacement monitoring systems to carry out risk analysis [36][37][38][39][40][41][42], and displacement transducers can be used at specific locations. Moreover, other methods such as groundwater level monitoring can also provide a reference for EWSs.…”