Tectonic and oceanographic control of sedimentary patterns in a small oceanic basin: Dove Basin (Scotia Sea,Antarctica)

Dove Basin, a small oceanic domain located within the southern Scotia Sea, evidences a complex tectonic evolution linked to the development of the Scotia Arc. The basin also straddles the junction between the main Southern Ocean water masses: the Antarctic Circumpolar Current (ACC), the Southeast Pacific Deep Water (SPDW) and the Weddell Sea Deep Water (WSDW). Analysis of multichannel seismic reflection profiles, together with swath bathymetry data, reveals the main structure and sediment distribution of the basin, allowing a reconstruction of the tectonostratigraphic evolution of the basin and assessment of the main bottom water flows that influenced its depositional development. Sediment dispersed in the basin was largely influenced by gravity‐driven transport from adjacent continental margins, later modified by deep bottom currents. Sediments derived from melting icebergs and extensive ice sheets also contributed to a fraction of the basin deposits. We identify four stages in the basin evolution which – based on regional age assumptions – took place during the early Miocene, middle Miocene, late Miocene–early Pliocene and late Pliocene–Quaternary. The onsets of the ACC flow in Dove Basin during the early Miocene, the WSDW flow during the middle Miocene, and the SPDW during the late Miocene were influenced by tectonic events that facilitated the opening of new oceanic gateways in the region. The analysis of Dove Basin reveals that tectonics is a primary factor influencing its sedimentary stacking patterns, the structural development of new oceanic gateways permitting the inception of deep‐water flows that have since controlled the sedimentary processes.     

A simple method to help determine landslide susceptibility from spaceborne InSAR data: the Montescaglioso case study

On December 3, 2013, a large complex landslide was triggered SW of the town of Montescaglioso (Southern Italy), causing the destruction of roads, commercial buildings and private dwellings, as well as several direct and indirect economic losses. A set of interferometric ground measurements acquired by the Cosmo-SkyMed satellite constellation and processed by means of the SqueeSAR algorithm was used to study the pre-event slope displacements in the entire Montescaglioso municipal area. Data span from January 30, 2012, to December 2, 2013, and show average line-of-sight velocities of 1–10 mm/year in the slope sector ultimately affected by the collapse. In retrospect, a time series analysis of the radar targets was performed in order to identify and characterize all the slope instabilities in proximity of the town. This was based on the setup of characteristic thresholds of displacement. The procedure permitted to locate several areas which recurrently exceeded these previously established thresholds, in consistency with the amount of precipitation. In particular, the major source of potential hazard in the area was indeed found where the December 3, 2013, landslide eventually occurred. The results of this quick data processing technique were validated through comparison with two independently developed landslide maps. This simple method, which is not supposed to diminish the importance of geomorphologic field surveys, could improve both the accuracy and the update rate of landslide susceptibility maps. Not relying on arbitrary or empirically derived approaches, it has the advantage of computing statistically based thresholds specific for each time series. By indicating the slope sectors in higher need of deeper in situ investigation, more support could be provided to administrative bodies for the processes of risk assessment and management.     

Ground‐based InSAR reveals conduit pressurization pulses at Stromboli volcano

At Stromboli volcano (Southern Italy), only few minor precursors (gas output) have been identified for ‘major’ Strombolian explosions. We use ground‐based interferometric synthetic aperture radar (GBInSAR) technology to monitor the displacement rate of the summit area of Stromboli. We analysed the 2009–2011 period. The analysis of the displacement rate has been performed by dividing the summit zone monitored by the GBInSAR into three regions, corresponding to the edge of the crater area (1 and 2), and to the slope of the NE crater (3). Pulses of rapid expansion of sector 3, of variable duration and amplitude, appear in coincidence with periods of intense activity that include lava flows and major explosions. We associate this expansion with the pressurization of the magma column that is recharged by deep‐derived gas, promoting the onset of ‘major explosion‐dominated’ activity.     

A BPR approach to hydrogeological risk management

Every year, landslides and floods cause deaths, missing persons, injured people, evacuees, and homeless people. Serious damages to property and pollution are also produced. Lessons learn from landslides and flood disasters recently occurred show that flood and disaster management should be widely improved. This paper deals the problem of hydrogeological risk management from a logistic and a managerial point of view. The hydrological risk management is studied as an industrial process, and it is modeled by the IDEF0 language. The IDEF0 application provides a clear overview of the system and became a structured base for the re-engineering process. For each function of the process, the inputs, outputs, and necessary controls and resources have been identified. The use of the IDEF0 provides a simple and effective tool for the decision-making process. Starting from a realistic and efficient current state model, the process of re-engineering has been implemented. The main aim of the change introduced in the process is to improve the information management that it is a crucial point of the risk management.