12 settembre ore 12:00-13:00
Auditorium De Carlo
Amato A.: Earthquakes and tsunamis: old and new defensive strategies between "real" and perceived hazard
13 settembre ore 14:30-15:30
Auditorium De Carlo
Chiari G.: Contribution of Geosciences to the study and preservation of art and cultural heritage
14 settembre ore 14:30-15:30
Auditorium De Carlo
Crosta G.: Large landslides as natural large scale laboratories for understanding geological processes and risks
Earthquakes and tsunamis: old and new defensive strategies between "real" and perceived hazard
Centro Nazionale Terremoti - I.N.G.V. Roma
The reduction of seismic risk has been historically faced using two approaches: the first one includes the evaluation of (long-term) hazard and the reduction of building vulnerability; the second one has focused on reducing the exposition through last minute actions, i.e., earthquake prediction / forecast. Whereas the first approach has brought to significant reduction of loss of both human lives and assets, particularly in countries where the frequency of large earthquakes is high, the second one has not, with very few lucky exceptions.
In Italy, despite a long history of research and achievements in hazard studies, a high quality of seismic engineering expertise, and several "antiseismic" laws, a long-term plan of vulnerability reduction has never been really implemented. The recent earthquakes in central Italy have led to a renewed attention to the problem, but the innovation introduced by Law 232/2016 (and subsequent decrees) still appears to be a too weak stimulus to solve the problem.
Reducing the exposition to earthquakes in the short term is possible in particular conditions. While the current knowledge on earthquake precursors and short term variations of seismic hazard does not allow us to devise any effective action to reduce the exposition just before an earthquake strikes, the implementation of Early Warning systems (EWS) is a viable way to reduce the impact of earthquakes (and tsunamis). For earthquakes, the time available to issue an alert, after the earthquake generation and before the strongest shaking, is very short (seconds to tens of seconds), particularly for crustal shallow earthquakes like those affecting our country. However, the enactment of some defensive actions, such as warning people and automatically securing some industrial, medical, transportation systems may contribute to save human lives and reduce damage.
For tsunamis induced by earthquakes, the times to issue an alert are in the order of minutes to hours. Therefore, the effectiveness of EWS is high, provided that a rapid, effective seismic monitoring system is operational. I will describe the achievements and the criticalities of the Italian tsunami alerting system for the Mediterranean, which was established in 2017 by a Prime Minister Directive (DPCM G.U. 5/6/2017) and operates within the ICG/NEAMTWS framework of IOC-UNESCO.
For both earthquakes and tsunamis, a fundamental tile towards risk reduction is people's knowledge and awareness. A continuous and more focused commitment by scientists, media, authorities, is needed in order to stimulate virtuous behaviors and effective action.
Contribution of Geosciences to the study and preservation of art and cultural heritage
The Getty Conservation Institute - Los Angeles
A brief introduction will define what Cultural heritage is from the Conservation Science point of view and will explain how the scenario changed with the advent of different materials in contemporary art.
Goals of the study (archaeometry and conservation).
Impact of rapid technological advances resulting in a flourishing of new instrumentation.
Use of large facilities (synchrotron and neutron sources) compared to the proliferation of small portable noninvasive instruments.
Composition of the Na-pyroxenes in green stone axes by a noninvasive XRD technique to determine the stone provenance, used for elucidating the trades in Neolithic Europe.
Texture of the copper axe of Similaum man shed light to the metallurgy of Eneolithic period.
For large facilities: Structure refinement of Maya Blue and identification of indigo in the palygorskite grooves. Use of neutrons for CT-scan of large statues (Robert van Lange), compared to powerful X-ray sources and medical equipment (Casali, Getty).
For portable instruments: Ubiquitous use of hand held XRF. Advantages and disadvantages. Portable Raman, FTIR, XRF/XRD noninvasive techniques. Some examples of non-conventional applications of portable XRD.
Michelangelo Last Judgment censure panels in the Sistine chapel: problem of dating the interventions with the goal of removing the most recent ones only. XRD proved to be the solution since the three painters used different yellow pigments. Discoloration of the blue sky painted with Lapis Lazuli. It was proved to be a rough partial cleaning performed using ash.
Imaging has become very important: Multispectral Imaging, involving different filters and light sources from UV to IR, helps mapping the various substances on the surface.
VIL, Visible Induced Luminescence, allows to take pictures of Egyptian blue only. Examples from Roman-Egyptian funerary paintings (Fayum), Herculaneum and X century Lombard church.
Reflectance Texture Imaging, combines many pictures taken at different illumination angles, and allows for changing the light direction on the computer at a touch of the mouse.
When X-ray Radiography in transmission is not practical, it can be substituted by Electron Emission, which involves the first 50 micrometers of surface only.
SmART_scan: a program that simulates XRF scanners, without the expensive equipment.
Large landslides as natural large scale laboratories for understanding geological processes and risks
Dipartimento di Scienze dell'ambiente e della Terra - Univ. di Milano Bicocca
Large landslides can represent a meeting point for knowledge belonging to different fields of geological sciences. The involved phenomena of rupture and evolution are made complex and controlled by the lithological, structural, physical and mechanical characteristics, by the meteorological and climatic perturbations as well as by the human action. Their size and the relationships with the morphology of slopes and watersheds can lead to different sensitivities to external factors, both natural and anthropogenic. Their presence is the answer to a complex combination of factors and they can provide the key to understanding geomorphological evolution even in distant or unreachable sites. Their observation and monitoring allow us to acquire data without which the modeling of instability risks not being representative. The evolution after the rupture and during the catastrophic collapse can be extremely varied and involves processes studied based on the characteristics of the deposits, their geometry, the degree of fragmentation and the released energy, through theoretical, numerical and scaled models, and partly on analogues of different geological phenomena. This lecture wants to highlight how around these aspects has grown and can increase the knowledge of phenomena and the behavior of materials, an interest limited not only to the geological applications and geomechanical aspects. For this purpose, examples of landslides in different contexts will be shown, highlighting how these can allow the understanding of the acting mechanisms and how multidisciplinary experimentation and observation can be indispensable tools for assessing their hazard and the associated risks.