Conference materials
Permanent URI for this collection
Browse
Recent Submissions
- PublicationOpen AccessExperimentation of new technologies for volcano gravimetry at Mt. Etna(2023-07-16)
; ; ; ; ; ; ; ; ; ; ; ; ; Among the geophysical techniques used to monitor volcanic unrest, only gravimetry can supply direct information on changes in the distribution of underground mass over time and can thus provide unique insight into processes such as magma accumulation in void space or gas segregation at shallow depths. Despite its great potential, time-variable volcano gravimetry is not widely adopted, mainly due to the high cost of instrumentation and the difficulty in assessing the relatively small volcano-related gravity changes against unfavorable environmental conditions. Several past studies from Mt. Etna have highlighted the value of gravity observation for improving our understanding of how volcanoes work and characterizing volcanic hazards. In the early stages of application at Mt. Etna, time-lapse and continuous gravity measurements were accomplished using spring gravimeters. Successively, gravimeters based on different technologies have been employed, including superconducting and quantum devices. In most cases, these applications were world firsts at an active volcano. Here, results from different gravimeter types, that have been used to monitor and study Mt. Etna, are presented. Furthermore, the perspectives opened by emerging technologies are highlighted.10 1 - PublicationOpen AccessThe absolute gravity network of Italy in the framework of the ITGRS/ITGRF(2024-09-04)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The activities for establishing the Italian Reference Gravity Network started in 2022. This is in line with the actions promoted by the International Association of Geodesy that during its 2015 General Assembly approved a resolution on the establishment of the new global gravity network the so-called International Terrestrial Gravity Reference System/Frame that will replace IGSN71. An initial set of 30 stations has been defined over the peninsular part of Italy and the two main islands of Sicily and Sardinia. Particularly, the GGOS core station of Matera (the Agenzia Spaziale Italiana Center for Space Geodesy “Bepi” Colombo) is one of the network points as required in the documents of the GGOS-Bureau of Networks and Observations. Thus, this station will provide one link between the Italian national absolute gravity network and the GGOS observation system of IAG. In order to ensure the measurements traceability, as required by the international standards on gravity measurements, the absolute gravimeters used in the measurements participated in international comparison campaigns. Absolute gravity measurements have been supplemented with direct measurements of the local value of the vertical gravity gradient, in order to reduce the absolute values, measured by different instruments at different heights, to an intermediate and common reference height and to the ground reference level to transport it to an external associated station. The gravity field campaigns have been assisted by topographic survey campaigns, allowing a centimetric georeferencing of the gravity stations to the current ITRF. The collected data will be then validated and reduced following the internationally accepted standards and finally published through a dedicate web page of the project. These data will also be submitted to the absolute gravity database maintained by the Bureau Gravimétrique International/Bundesamt fuer Kartographie und Geodaesie where the absolute gravity data that will contribute to the new global absolute gravity reference system are collected.21 7 - PublicationOpen AccessThe role of women in the geosciences: the case of INGV in preparing and managing the emergencies(2024-09-03)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; It is well known that in the geosciences (as in all STEM disciplines), the percentage of women in top positions decreases in favor of men, despite comparable academic careers and, sometimes, even better results for women. The authors of this contribution hold managerial roles in preparing and managing seismic and tsunami emergencies at INGV. It has been a long journey, but it is now a positive reality. But it has sometimes been different! Since its establishment in 1999, the INGV has undergone significant growth and transformation. De Lucia et al. in 2021 [1] analyzed gender diversity within the organization, revealing that the workforce comprised 38% female and 62% male. While these proportions have remained relatively stable over subsequent years, nuances emerge when examining gender distribution with higher representation of women in administrative roles and men in technical positions. What is slowly changing in recent years is the presence of women in research and managerial leadership positions. Notably, between 2016-2020, a woman served as General manager and, since 2017, one of the three Department Directors (Environment, Earthquakes and Volcanoes) is a woman. Currently, 4 out of the 10 Directors of the INGV Offices are women, reflecting a positive trend towards gender parity in leadership roles. Additionally, both the recently elected INGV members of the Scientific Council are women, underscoring the growing influence of female voices in shaping scientific discourse and decision-making. In the present day, an increasing number of women fulfill pivotal roles across research, technical, and administrative realms, actively contributing to coordination and leadership. Notable instances include women actively engaged in the preparation and execution of seismic, volcanic and tsunami emergency protocols. Their responsibilities encompass crucial tasks and providing support services for emergency response teams (including operational rooms for seismic, volcanic, and tsunami surveillance, network monitoring infrastructures, or emergency response teams). In this contribution, the authors recount their experiences.21 5 - PublicationOpen AccessEarthquake Induced Landslides (EILs) occurrence and earthquake parameters: new empirical relationships developed using the updated CFTI historical dataset(2023-02)
; ; ; ; ; ; ; ; ;; ;; ; ; ; The ground shaking generated by the arrival of seismic waves released during earthquakes, besides generating damages to the urban environment and artificial infrastructures, can trigger widespread environmental coseismic effects, overall defined as secondary Earthquake Environmental Effects (EEE) in the Environmental Seismic Intensity scale (ESI; Michetti et al., 2007). These natural effects include river ponding or diversion, liquefaction, ground compaction and failures and, among all, landslides. If, due to geological and geomorphological reasons, the area hit by the earthquake is susceptible to their occurrence, they take place almost constantly, regardless of the kinematic characteristics of the seismogenic sources, and affect areas of variable size according to the earthquake magnitude. Besides potentially increasing overall earthquake damage immediately after the mainshock, they pose long lasting secondary hazards to earthquake affected areas (e.g. Fan et al., 2019), driving also the long-term morphological evolution of the territory (e.g. Wang et al., 2020). Earthquake Induced Landslides (EILs) are among the most diffused environmental hazard connected to the earthquake activity, and especially affect recent, high relief mountain landscapes associated to the ongoing tectonic plate dynamics. There exist in fact reciprocal feedbacks between active tectonics, which in the long-term creates the predisposing morphological and geological factors, and landslide activity, which works for lowering the topographic gradients. Italy sits on the plate boundary separating the slowly converging Eurasia and Nubia plates, which in the long run created its mostly mountain territory, and is characterized by a relatively high seismic hazard. The combination of the relatively frequent seismic release and the locally high landslide susceptibility (Fig. 1), makes the Italian territory especially prone to EILs occurrence. This is testified by the numerous coseismic landslide inventories compiled after recent earthquakes (e.g. Guzzetti et al., 2009). As a first step of our workflow, we revised the database of seismic induced environmental effects connected to the CFTI5Med historical seismic catalogue (available at https://storing.ingv.it/cfti/cfti5/; Guidoboni et al., 2018; 2019). To achieve this goal, we collected new data points from new historical sources, revised the EILs already included in CFTI, and finally, in a dedicated GIS environment, we tried to locate them on topographic maps using the coeval descriptions. In some cases, it was possible to associate the historical EILs to landslides included and described in the Italian Landslide Inventory (IFFI database; Trigila et al., 2007). Following this, landslides were subdivided into three classes according to their positioning precision, i.e.: Class A if they were geographically well located using a toponymal (AI if associated to one of landslides included in IFFI); Class B, if they were generally located in an area (BI if associated to one of landslides included in IFFI); Class C, if not localized. The revised CFTI database includes more than 1000 historical EILs, associated to 159 individual earthquakes or seismic sequences occurred between 117 B.C.E. and 1997 (Fig. 2). With respect to the datasets used so far for deriving empirical relationships (e.g. Livio and Ferrario, 2019; Tanyaş et al., 2017), these figures dramatically increase the number of available data points for the Italian territory. As a second step, the implemented database was used to develop new empirical attenuation relationships between the EILs density and the distance from the epicenter as a function of the earthquake magnitude. Then, we subdivided seismic events into three magnitude classes to account for the different extent of the maximum area affected by EILs and released energy. The three classes are as follows: Class 1, M < 5.5; Class 2, 5.5 ≤ M < 6.5, and Class 3, M ≥ 6.5. Based on the locations of EILs and of epicenters, we set circular search areas with a 5 km large moving window and calculated for each area the cumulative density. We found that the cumulative density decreases with the distance following a power law relationship, with coefficients of determination variable between 0.95 and 0.99 according to the magnitude class, and that the maximum distance including 95th percentile of landslides increases with increasing magnitude range. In particular, the 95th percentile distance, i.e. the distance within which 95% of EILs are expected to occur, is 42 km for earthquakes of Class 1, 66 km for those of Class 2, and 77 km for those of Class 3. In addition, using the shakemaps of 38 out of 159 historical earthquakes of our dataset, we developed an empirical relationship between EILs density and PGA values. The shakemaps of historical earthquakes were recently published by the Istituto Nazionale di Geofisica e Vulcanologia and are available at http://shakemap.ingv.it/shake4/. EILs density was computed by classifying PGA values into classes of 0.1 g range. We used the EILs location to sample the PGA value and derive a power law relationship showing an increasing landslide density with increasing acceleration. As a final step, these empirical relationships were used to relate each landslide belonging to the Italian national inventory (IFFI) to individual segments of known seismogenic sources located in the Italian territory or in nearby countries within a maximum distance corresponding to the 95th percentile distance calculated from the expected magnitude of the seismogenic source (Fig. 2). We used the composite seismogenic sources of the DISS database version 3.3.0 (DISS Working Group, 2021) hypothesizing that they may trigger the EILs activation during future earthquakes and, using a floating hypocenter approach, i.e. shifting the hypocenters along the seismogenic sources with 4 km fixed steps, built preliminary EILs scenarios for each potential hypocenter location.4 3 - PublicationOpen AccessMapping earthquake-induced landslide hazard in Italy.(2023-11)
; ; ; ; ; ; ; ; ; ;; ;; ; ;Earthquake generated ground shaking triggers widespread environmental coseismic phenomena, defined as secondary Earthquake Environmental Effects in the Environmental Seismic Intensity scale (ESI). Among them, Earthquake Induced Landslides (EILs) are the most diffused, especially affecting young, high relief terrains associated to the ongoing plate tectonic dynamics. EILs can be reactivation of pre-existing landslides or activation of new ones where favourable geologic conditions exist. In this work, we try to answer the following questions: which of the pre-existing landslides more probably will be reactivated, and where is more probable to trigger new EILs during future earthquakes? We used complementary datasets available for the Italian territory: 1) the Italian and European seismic hazard models showing, over spatially uniform grids, the probability of exceedance of the seismic action within a fixed time span; 2) the Database of Individual Seismogenic Sources (DISS; https://diss.ingv.it/), that includes faults responsible for the seismic activity; 3) the Italian Landslide Inventory database (IFFI); and 4) the European Landslide Susceptibility Map (ELSUS v2). We also used new empirical relationships relating the variation of EILs density with distance from the earthquake epicentre (A), and the variation of EILs density with seismic shaking (B), that were calculated using the Italian database of historical seismic induced landslides (Zei et al., 2023) and a shakemap dataset of historical earthquakes as input data. To answer the first question, we used the distance corresponding to the 95th percentile of landslide occurrence (95DIST), derived from the empirical relationship (A). This allowed to sum for each landslide the number of possible epicentres located along the DISS composite seismogenic sources and falling within that distance. The location of the epicentres was determined using a floating fault approach, where a typical fault associated to a maximum credible earthquake (MCE), was shifted of a fixed distance along-strike of the seismogenic faults. We also calculated the probability of occurrence of each MCE and derived the probability for each landslide that an earthquake of a certain magnitude could occur within 95DIST. The second question was addressed merging over a uniform grid the seismic hazard and the landslide susceptibility data, by multiplying their values, and highlighting in this way areas where the probability of triggering new landslides is maximum due to seismic and geologic predisposing factors. Finally, to obtain the EILs hazard, we calculated the conditional probability of reactivation of each landslide of our dataset. This was obtained combining 1) the cumulated probability of occurrence of the earthquakes of different magnitude classes falling within the 95DIST with 2) the probability of reactivation of the landslide in function of the epicentral distance, as derived from the empirical relationship (A). We also calculated the conditional probability of inducing new landslides using the landslide density function of empirical relationship (B) applied to the seismic hazard and landslide susceptibility combined map.2 1