Massive data collection in volcanic areas owing to photogrammetry-derived models: a key example from the NE Rift, Mt Etna (Italy).

2021 ◽  
Author(s):  
Emanuela De Beni ◽  
Alessandro Tibaldi ◽  
Noemi Corti ◽  
Fabio L. Bonali ◽  
Susanna Falsaperla ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Normal Fault ◽  
Weather Conditions ◽  
3D Models ◽  
Point Of View ◽  
Normal Faults ◽  
Extension Rate ◽  
Strong Wind ◽  
Mt Etna ◽  
Ne Rift

<p>The collection of a conspicuous amount of data in volcanic areas is a key for a deeper understanding of the relationships between faulting, diking and superficial volcanic processes. A way to quickly collect huge amounts of data is to analyse photogrammetry-derived models (Digital surface models, orthomosaics and 3D models) using Unmanned Aerial Vehicles (UAVs) to collect all necessary pictures obtaining final models with a texture ground resolution up to 2-3 cm/pix.</p><p>In this work, we describe our approach to build up models of a broad area located in the NE Rift of Mt. Etna, which is affected by continuous ground deformation linked to gravity sliding of the eastern flank of the volcano and dyke injection. The area is characterized by the presence of eruptive craters and fissures, extension fractures, and normal faults, as well as by historical lava flows. The goal was to quantify the kinematics at extensional fractures and normal faults, integrating the latter with seismological data to reconstruct the stress field acting in this peculiar sector of the volcano. By the point of view of UAV surveying, the test area is challenging since it is located at an altitude ranging between 2700 and 1900 m a.s.l., and it is affected by extreme weather conditions, like a strong wind. Resulting models, in the form of DSM and orthomosaic, are characterised by a resolution of 11.86 and 2.97 cm/pix, respectively, obtained from the elaboration of 4018 photos and covering an area of 2.2 km<sup>2</sup>. Thanks to these models, we recognized the presence of 20 normal fault segments, 250 extension fractures, and 54 single eruptive fissures. Considering all the above mention data, we quantified the kinematics at extensional fractures and normal faults, obtaining an extension rate of 1.9 cm/yr for the last 406 yr.</p>

Multidisciplinary analyses for mapping and evaluating kinematics and stress/strain field at active faults and fissures at NE Rift, Mt Etna (Italy)

2021 ◽  
Author(s):  
Susanna Falsaperla ◽  
Alessandro Tibaldi ◽  
Noemi Corti ◽  
Emanuela De Beni ◽  
Fabio L. Bonali ◽  
...  
Keyword(s):  
Active Faults ◽  
Normal Fault ◽  
Structural Data ◽  
Field Work ◽  
Normal Faults ◽  
Extension Rate ◽  
Mt Etna ◽  
Hazardous Zone ◽  
Eruptive Fissures ◽  
Ne Rift

<p>Strategies for disaster risk reduction in volcanic areas are mostly driven by multidisciplinary analyses, which offer effective and complementary information on complex geomorphological and volcano-tectonic environments. For example, quantification of the offset at active faults and fissures is of paramount importance to shed light on the kinematics of zones prone to deformation and/or seismic activity. This provides key information for the assessment of seismic hazard, but also for the identification of conditions that may favor magma uprising and opening of eruptive fissures.</p><p>Here we present the results of a study encompassing detailed geological, structural and seismological observations focusing on part of the NE Rift at Etna volcano (Italy). The area is situated at an elevation ranging between 2700 and 1900 m a.s.l. where harsh meteorological conditions and difficult logistics render classical field work a troublesome issue. In order to bypass these difficulties, high-resolution (2.8 cm) UAV survey has been recently completed. The survey highlights the presence of 250 extension fractures, 20 normal fault segments, and 54 eruptive fissures. The study allows us to quantify the kinematics at extensional fractures and normal faults, obtaining an extension rate of 1.9 cm/yr for the last 406 yr. With a total of 432 structural data collected by UAV along with SfM photogrammetry, this work also demonstrates the suitability of the application of such surveys for the monitoring of hazardous zone.</p>

scholarly journals Mapping and evaluating kinematics and the stress and strain field at active faults and fissures: a comparison between field and drone data at the NE rift, Mt Etna (Italy)

Solid Earth ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 801-816
Author(s):  
Alessandro Tibaldi ◽  
Noemi Corti ◽  
Emanuela De Beni ◽  
Fabio Luca Bonali ◽  
Susanna Falsaperla ◽  
...  
Keyword(s):  
Stress Field ◽  
Best Practice ◽  
Ground Deformation ◽  
Active Faults ◽  
Fault System ◽  
Normal Faults ◽  
Extension Rate ◽  
Eastern Flank ◽  
Mt Etna ◽  
Ne Rift

Abstract. We collected drone data to quantify the kinematics at extensional fractures and normal faults, integrated this information with seismological data to reconstruct the stress field, and critically compared the results with previous fieldwork to assess the best practice. As a key site, we analyzed a sector of the northeast rift of Mt Etna, an area affected by continuous ground deformation linked to gravity sliding of the volcano's eastern flank and dike injections. The studied sector is characterized also by the existence of eruptive craters and fissures and lava flows. This work shows that this rift segment is affected by a series of NNE- to NE-striking, parallel extensional fractures characterized by an opening mode along an average N105.7∘ vector. The stress field is characterized by a σHmin trending northwest–southeast. Normal faults strike parallel to the extensional fractures. The extensional strain obtained by cumulating the net offset at extensional fractures with the fault heave gives a stretching ratio of 1.003 in the northeastern part of the study area and 1.005 in the southwestern part. Given a maximum age of 1614 CE for the offset lavas, we obtained an extension rate of 1.9 cm yr−1 for the last 406 years. This value is consistent with the slip along the Pernicana Fault system, confirming that the NE rift structures accommodate the sliding of the eastern flank of the volcano.

scholarly journals Mapping and evaluating kinematics and stress/strain field at active faults and fissures: a comparison between field and drone data at NE Rift, Mt Etna (Italy)

2021 ◽  
Author(s):  
Alessandro Tibaldi ◽  
Noemi Corti ◽  
Emanuela De Beni ◽  
Fabio Luca Bonali ◽  
Susanna Falsaperla ◽  
...  
Keyword(s):  
Stress Field ◽  
Best Practice ◽  
Ground Deformation ◽  
Active Faults ◽  
Normal Faults ◽  
Extension Rate ◽  
North East ◽  
The North ◽  
Mt Etna ◽  
Dyke Injection

Abstract. We collected drone data to quantify the kinematics at extensional fractures and normal faults, integrated this information with seismological data to reconstruct the stress field, and critically compared the results with previous fieldwork to assess the best practice. As key site, we analysed a sector of the North-East Rift of Mt Etna, an area affected by continuous ground deformation linked to gravity sliding of the volcano's eastern flank and dyke injection. The studied sector is characterized also by the existence of eruptive craters and fissures and lava flows. This work shows that this rift segment is affected by a series of NE-striking, parallel extensional fractures characterized by an opening mode along an average N105.7° vector. Normal faults strike parallel to the extensional fractures, although they tend to bend slightly when crossing topographic highs corresponding to pyroclastic cones. The extensional strain obtained by cumulating the net offset at extensional fractures with the fault heave gives a stretching ratio of 1.003 in the northeastern part of the study area and 1.005 in the southwestern part. Given a maximum age of 1614 yr AD for the offset lavas, we obtained an extension rate of 1.9 cm/yr for the last 406 yr. The stress field is characterised by a σHmin trending NW-SE. Results indicate that Structure-from-Motion photogrammetry applied to drone surveys allows to collect large amounts of data with a resolution of 2–3 cm, a detail comparable to field surveys. In the same amount of time, drone survey can allow to collect more data than classical fieldwork, especially in logistically difficult rough terrains.

Effectiveness of Flood Protection Project Valuation Methods

2015 ◽  
Vol 10 (3) ◽  
pp. 275-289
Author(s):  
Tadeusz Liziński ◽  
Marcin Bukowski ◽  
Anna Wróblewska
Keyword(s):  
Essential Element ◽  
Weather Conditions ◽  
Point Of View ◽  
Flood Protection ◽  
Costs And Benefits ◽  
Protection Measures ◽  
Investment Projects ◽  
Market Values ◽  
Project Valuation ◽  
The Subject

Projects for flood protection are increasingly the subject of investment projects in the field of water management. This is related to the increasing frequency of worldwide threats caused by extreme weather conditions, including extremely high rainfall causing floods. Technical and nontechnical flood protection measures are also increasing in importance. In the decision-making process, it is necessary to take into account both the costs and benefits of avoiding losses, including an analysis of social benefits, whose valuation of non-market goods is an essential element. A comprehensive account of projects in the field of flood protection based on the estimated costs and benefits of the investment allows the economic efficiency from a general social point of view to be determined. Previous evaluations of the effectiveness of investment projects have mainly taken into account only categories and market values. The aim of the article is to identify the possibilities to expand the values of non-market assessments and categories formulated on the basis of the theoretical economics of the environment. 

scholarly journals Design and Field Validation of a Low Power Wireless Sensor Node for Structural Health Monitoring

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1050
Author(s):  
Federico Zanelli ◽  
Francesco Castelli-Dezza ◽  
Davide Tarsitano ◽  
Marco Mauri ◽  
Maria Laura Bacci ◽  
...  
Keyword(s):  
Low Power ◽  
Sensor Node ◽  
Weather Conditions ◽  
Point Of View ◽  
Design Stage ◽  
Monitoring Systems ◽  
Wireless Sensor Node ◽  
Process Data ◽  
Fatigue Life Estimation ◽  
Remaining Fatigue Life

Smart monitoring systems are currently gaining more attention and are being employed in several technological areas. These devices are particularly appreciated in the structural field, where the collected data are used with purposes of real time alarm generation and remaining fatigue life estimation. Furthermore, monitoring systems allow one to take advantage of predictive maintenance logics that are nowadays essential tools for mechanical and civil structures. In this context, a smart wireless node has been designed and developed. The sensor node main tasks are to carry out accelerometric measurements, to process data on-board, and to send wirelessly synthetic information. A deep analysis of the design stage is carried out, both in terms of hardware and software development. A key role is played by energy harvesting integrated in the device, which represents a peculiar feature and it is thanks to this solution and to the adoption of low power components that the node is essentially autonomous from an energy point of view. Some prototypes have been assembled and tested in a laboratory in order to check the design features. Finally, a field test on a real structure under extreme weather conditions has been performed in order to assess the accuracy and reliability of the sensors.

scholarly journals Combining High- and Low-Rate Geodetic Data Analysis for Unveiling Rapid Magma Transfer Feeding a Sequence of Violent Summit Paroxysms at Etna in Late 2015

2021 ◽  
Vol 11 (10) ◽  
pp. 4630
Author(s):  
Alessandro Bonforte ◽  
Flavio Cannavò ◽  
Salvatore Gambino ◽  
Francesco Guglielmino
Keyword(s):  
Ground Deformation ◽  
High Rate ◽  
Rate Data ◽  
Scale Analysis ◽  
Feeding System ◽  
Magma Sources ◽  
Mt Etna ◽  
Multi Temporal ◽  
Gnss Measurements ◽  
Low Rate

We propose a multi-temporal-scale analysis of ground deformation data using both high-rate tilt and GNSS measurements and the DInSAR and daily GNSS solutions in order to investigate a sequence of four paroxysmal episodes of the Voragine crater occurring in December 2015 at Mt. Etna (Italy). The analysis aimed at inferring the magma sources feeding a sequence of very violent eruptions, in order to understand the dynamics and to image the shallow feeding system of the volcano that enabled such a rapid magma accumulation and discharge. The high-rate data allowed us to constrain the sources responsible for the fast and violent dynamics of each paroxysm, while the cumulated deformation measured by DInSAR and daily GNSS solutions, over a period of 12 days encompassing the entire eruptive sequence, also showed the deeper part of the source involved in the considered period, where magma was stored. We defined the dynamics and rates of the magma transfer, with a middle-depth storage of gas-rich magma that charges, more or less continuously, a shallower level where magma stops temporarily, accumulating pressure due to the gas exsolution. This machine-gun-like mechanism could represent a general conceptual model for similar events at Etna and at all volcanoes.

The 4 December 2015 Mw 7.1 Normal-Faulting Antarctic Plate Earthquake and Its Seismotectonic Implications

2020 ◽  
Vol 110 (3) ◽  
pp. 1090-1100
Author(s):  
Ronia Andrews ◽  
Kusala Rajendran ◽  
N. Purnachandra Rao
Keyword(s):  
Body Wave ◽  
Focal Depth ◽  
Normal Fault ◽  
Normal Faults ◽  
Oceanic Plate ◽  
Normal Faulting ◽  
Transform Faults ◽  
Wave Inversion ◽  
Spreading Ridges ◽  
Southeast Indian Ridge

ABSTRACT Oceanic plate seismicity is generally dominated by normal and strike-slip faulting associated with active spreading ridges and transform faults. Fossil structural fabrics inherited from spreading ridges also host earthquakes. The Indian Oceanic plate, considered quite active seismically, has hosted earthquakes both on its active and fossil fault systems. The 4 December 2015 Mw 7.1 normal-faulting earthquake, located ∼700  km south of the southeast Indian ridge in the southern Indian Ocean, is a rarity due to its location away from the ridge, lack of association with any mapped faults and its focal depth close to the 800°C isotherm. We present results of teleseismic body-wave inversion that suggest that the earthquake occurred on a north-northwest–south-southeast-striking normal fault at a depth of 34 km. The rupture propagated at 2.7  km/s with compact slip over an area of 48×48  km2 around the hypocenter. Our analysis of the background tectonics suggests that our chosen fault plane is in the same direction as the mapped normal faults on the eastern flanks of the Kerguelen plateau. We propose that these buried normal faults, possibly the relics of the ancient rifting might have been reactivated, leading to the 2015 midplate earthquake.

Optimization of Restoration Paths of Power System after Blackout

2013 ◽  
Vol 347-350 ◽  
pp. 1467-1472
Author(s):  
Wen Wei Huang ◽  
Gang Yao ◽  
Xiao Yan Qiu ◽  
Nian Liu ◽  
Guang Tang Chen
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Reactive Power ◽  
Minimum Spanning Tree ◽  
Operation Time ◽  
Combinatorial Problem ◽  
Weather Conditions ◽  
Recovery Process ◽  
Point Of View ◽  
Improved Genetic Algorithm

Optimization of restoration paths of power system after blackout is a multi-stage, multi-target, multi-variable combinatorial problem in the power system restoration. This paper presents a reasonable model and effectually method. The proposed model is considered as a typical partial minimum spanning tree problem from the mathematical point of view which considering all kinds of constraints. Improved data envelopment analysis (DEA) was used to get the weight which considering line charging reactive power, weather conditions, operation time and betweenness of transmission lines. The improved genetic algorithm method is employed to solve this problem. Finally, an example is given which proves the strategy of the line restoration can effectively handle the uncertainty of the system recovery process, to guarantee the system successfully restored after the catastrophic accidents.

scholarly journals EVALUATION OF MODEL RECOGNITION FOR GRAMMAR-BASED AUTOMATIC 3D BUILDING MODEL RECONSTRUCTION

2016 ◽  
Vol XLI-B4 ◽  
pp. 63-69
Author(s):  
Qian Yu ◽  
Petra Helmholz ◽  
David Belton
Keyword(s):  
Laser Scanning ◽  
Quality Evaluation ◽  
Evaluation Process ◽  
3D Models ◽  
Point Of View ◽  
Three Dimensions ◽  
Public And Private ◽  
Building Models ◽  
Evaluation Point ◽  
Increasing Demand

In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.

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