Co-seismic and post-seismic changes in groundwater discharge: first results from the epicentral region of the Central Italy earthquake 2016

Abstract. This paper identifies the application domain, context of use, processes and goals of low-cost street-level photogrammetry after urban disasters. The proposal seeks a synergy between top-down and bottom-up initiatives carried out by different actors during the humanitarian response phase in data scarce contexts. By focusing on the self-organisation capacities of local people, this paper suggests using collaborative photogrammetry to empower communities hit by disasters and foster their active participation in recovery and reconstruction planning. It shows that this task may prove technically challenging depending on the specifics of the collected imagery and develops a grounded framework to produce user-centred image acquisition guidelines and fit-for-purpose photogrammetric reconstruction workflows, useful in future post-disaster scenarios. To this end, it presents an in-depth analysis of a collaborative photographic mapping initiative undergone by a group of citizen-scientists after the 2016 Central Italy earthquake, followed by the explorative processing of some sample datasets. Specifically, the paper firstly presents a visual ethnographic study of the photographic material uploaded by participants from September 2016 to November 2018 in the two Italian municipalities of Arquata del Tronto and Norcia. Secondly, it illustrates from a technical point of view issues concerning the processing of crowdsourced data (e.g. image filtering, selection, quality, semantic content and 3D model scaling) and discusses the viability of using it to enrich the pool of geo-information available to stakeholders and decision-makers. Final considerations are discussed as part of a grounded framework for future guidelines tailored to multiple goals and data processing scenarios.

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PSHA after a strong earthquake: hints for the recovery

Annals of Geophysics ◽

10.4401/ag-7257 ◽

2016 ◽

Vol 59 ◽

Author(s):

L. Peruzza ◽

R. Gee ◽

B. Pace ◽

G. Roberts ◽

O. Scotti ◽

...

Keyword(s):

Hazard Analysis ◽

Central Italy ◽

Safety Evaluation ◽

Preliminary Evidence ◽

Source Model ◽

Aftershock Sequence ◽

Earthquake Occurrence ◽

Central Italy Earthquake ◽

Complex Fault ◽

Fault Source

We perform aftershock probabilistic seismic hazard analysis (APSHA) of the ongoing aftershock sequence following the Amatrice August 24th, 2016 Central Italy earthquake. APSHA is a time-dependent PSHA calculation where earthquake occurrence rates decrease after the occurrence of a mainshock following an Omori-type decay. In this paper we propose a fault source model based on preliminary evidence of the complex fault geometry associated with the mainshock. We then explore the possibility that the aftershock seismicity is distributed either uniformly or non-uniformly across the fault source. The hazard results are then computed for short-intermediate exposure periods (1-3 months, 1 year). They are compared to the background hazard and intended to be useful for post-earthquake safety evaluation.

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Constraining families of dynamic models using geological, geodetic and strong ground motion data: the Mw 6.5, October 30th, 2016, Norcia earthquake, Italy

10.31223/x5vw38 ◽

2021 ◽

Author(s):

Elisa Tinti ◽

Emanuele Casarotti ◽

Thomas Ulrich ◽

Duo Li ◽

Taufiqurrahman Taufiqurrahman ◽

...

Keyword(s):

Dynamic Models ◽

Central Italy ◽

Kinematic Model ◽

Seismic Wave Propagation ◽

Dynamic Rupture ◽

Friction Coefficients ◽

Multiple Faults ◽

Central Italy Earthquake ◽

Trade Offs ◽

Kinematic Models

The 2016 Central Italy earthquake sequence is characterized by remarkable rupture complexity, including highly heterogeneous slip across multiple faults in an extensional tectonic regime. The dense coverage and high quality of geodetic and seismic data allow to image intriguing details of the rupture kinematics of the largest earthquake of the sequence, the Mw 6.5 October 30th, 2016 Norcia earthquake, such as an energetically weak nucleation phase. Several kinematic models suggest multiple fault planes rupturing simultaneously, however, the mechanical viability of such models is not guaranteed.Using 3D dynamic rupture and seismic wave propagation simulations accounting for two fault planes, we constrain 'families' of spontaneous dynamic models informed by a high-resolution kinematic rupture model of the earthquake. These families differ in their parameterization of initial heterogeneous shear stress and strength in the framework of linear slip weakening friction.First, we dynamically validate the kinematically inferred two-fault geometry and rake inferences with models based on only depth-dependent stress and constant friction coefficients. Then, more complex models with spatially heterogeneous dynamic parameters allow us to retrieve slip distributions similar to the target kinematic model and yield good agreement with seismic and geodetic observations. We discuss the consistency of the assumed constant or heterogeneous static and dynamic friction coefficients with mechanical properties of rocks at 3-10 km depth characterizing the Italian Central Apennines and their local geological and lithological implications. We suggest that suites of well-fitting dynamic rupture models belonging to the same family generally exist and can be derived by exploiting the trade-offs between dynamic parameters.Our approach will be applicable to validate the viability of kinematic models and classify spontaneous dynamic rupture scenarios that match seismic and geodetic observations at the same time as geological constraints.

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POST-DISASTER DAMAGE ASSESSMENT THROUGH COHERENT CHANGE DETECTION ON SAR IMAGERY

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-431-2018 ◽

2018 ◽

Vol XLII-3 ◽

pp. 431-436 ◽

Cited By ~ 3

Author(s):

L. Guida ◽

P. Boccardo ◽

I. Donevski ◽

L. Lo Schiavo ◽

M. E. Molinari ◽

...

Keyword(s):

Change Detection ◽

Damage Assessment ◽

Central Italy ◽

Weather Conditions ◽

Earthquake Scenario ◽

Central Italy Earthquake ◽

Novel Approach ◽

Coherent Change Detection ◽

Sar Imagery ◽

Bad Weather

Damage assessment is a fundamental step to support emergency response and recovery activities in a post-earthquake scenario. In recent years, UAVs and satellite optical imagery was applied to assess major structural damages before technicians could reach the areas affected by the earthquake. However, bad weather conditions may harm the quality of these optical assessments, thus limiting the practical applicability of these techniques. In this paper, the application of Synthetic Aperture Radar (SAR) imagery is investigated and a novel approach to SAR-based damage assessment is presented. Coherent Change Detection (CCD) algorithms on multiple interferometrically pre-processed SAR images of the area affected by the seismic event are exploited to automatically detect potential damages to buildings and other physical structures. As a case study, the 2016 Central Italy earthquake involving the cities of Amatrice and Accumoli was selected. The main contribution of the research outlined above is the integration of a complex process, requiring the coordination of a variety of methods and tools, into a unitary framework, which allows end-to-end application of the approach from SAR data pre-processing to result visualization in a Geographic Information System (GIS). A prototype of this pipeline was implemented, and the outcomes of this methodology were validated through an extended comparison with traditional damage assessment maps, created through photo-interpretation of high resolution aerial imagery. The results indicate that the proposed methodology is able to perform damage detection with a good level of accuracy, as most of the detected points of change are concentrated around highly damaged buildings.

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MASONRY IN PARALLEL. A KNOWLEDGE BASED STRATEGY POST CENTRAL ITALY EARTHQUAKE 2016

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xliv-m-1-2020-3-2020 ◽

2020 ◽

Vol XLIV-M-1-2020 ◽

pp. 3-9

Author(s):

C. Braucher ◽

E. Currà

Keyword(s):

Central Italy ◽

Field Research ◽

Masonry Buildings ◽

Knowledge Based ◽

Central Italy Earthquake ◽

Survey Form ◽

Umbria Region ◽

Post Traumatic ◽

New Form

Abstract. This research aims to propose a classification of masonry typologies in Central Italy after the earthquakes that in 2016 involved about 120 municipalities. This territory, since several decades, presents high fragility features due to the depopulation process that increase the vulnerability and risk degree. This condition affects even the maintenance practices of traditional buildings by the inhabitants and the extraordinary post-traumatic situation acts as an accelerating factor of the abandonment. In this article we will explain deeply the first part of the research, focusing in particular on methods and tools that were defined and used to carry out this study. The research highlights the need of a specific comparative tool for masonry facades classification. This was elaborated through the comparison of existed bibliography as the EMS-98, the Aedes schedules and the local classification by Umbria Region and the De Meo book. The result then is the production of another synoptic map that would simplifies the correlation between different approaches to classification and the censed facades. Moreover, it was elaborated a second synoptic map moving from the analyses of many survey forms already discuss in literature. The result of this comparison is a new survey form to carry out the field research on vernacular masonry buildings. This new form focuses on the characteristics of the buildings that the research aims to study in Central Italy. The two tools that are illustrate in the following paper were applied on one hundred survey of masonry buildings carried out during August 2018. The last part of this paper proposes a statistical analysis of the results of the field research.

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