197 research outputs found
On Operational Earthquake Forecast and Prediction Problems.
In his SSA presidential address (Jordan, 2014), and later in a more extended publication with coauthors (Jordan et al., 2014), Jordan presents a vision of forecast and prediction problems of earthquake system science. As experienced practitioners and in full appreciation of scientific studies on earthquake forecasting, we find it necessary to share a complementary viewpoint
Scenario-based Tsunami hazard assessment for Northeastern Adriatic coasts
Significant tsunamis in Northern Adriatic are rare and only a few historical
events were reported in the literature, with sources mostly located along with
central and southern parts of the Adriatic coasts. Recently, a tsunami alert
system has been established for the whole Mediterranean area; however, a
detailed description of the potential impact of tsunami waves on coastal areas
is still missing for several sites. This study aims at modelling the hazard
associated with possible tsunamis, generated by offshore earthquakes, with the
purpose of contributing to tsunami risk assessment for selected urban areas
located along the Northeastern Adriatic coasts. Tsunami modelling is performed
by the NAMI DANCE software, which allows accounting for seismic source
properties, variable bathymetry, and non-linear effects in waves propagation.
Preliminary hazard scenarios at the shoreline are developed for the coastal
areas of Northeastern Italy and at selected cities (namely Trieste, Monfalcone,
Lignano and Grado). A wide set of potential tsunamigenic sources of tectonic
origin, located in three distance ranges (namely at Adriatic-wide, regional and
local scales), are considered for the modelling; sources are defined according
to available literature, which includes catalogues of historical tsunami and
existing active faults databases. Accordingly, a preliminary set of
tsunami-related parameters and maps are obtained (e.g. maximum run-up, arrival
times, synthetic mareograms), relevant towards planning mitigation actions at
the selected sites.Comment: 31 pages, 15 figures and 4 table
Antigüedad
El tratamiento del interior en los edificios de culto durante el período conocido genéricamente como Antigüedad sufrió transformaciones cuyo origen estriba tanto en la participación de la sociedad en los ritos sagrados como en distintas tradiciones culturales acerca del espacio que se fueron sucediendo en las etapas formativas de la era. El Partenón – Atenas, s. V a.C – fue construido como casa y para honra de Atenea, no concebido para ser circulado sino como suprema ofrenda; la concepción estética y racional del espacio imponía magnificencia exterior y perfección proporcional. El Panteón – Roma, s. II d.C. – constituye un símbolo del proyecto constructivo romano, que se apropió del vocabulario formal griego pero lo combinócon su propia tradición constructiva basada en la expansión del espacio interior, y convirtió los elementos arquitectónicos en elementos para su diseño. La primera Basílica de San Pedro – Roma, 324 d.C. – es un ejemplo de edificación monumental pensada para que se reúna la nueva comunidad cristiana, cuya distribución de espacio unidireccional se subordina a la presencia del altar.Interior design of cult buildings has suffered transformations along antiquity which origin are, not only participation of society in sacred rites, but also different cultural traditions on space that happened during the primitive stages of the age. The Parthenon – Athens S V a C – was built as Athena’s house and in her honor, not born to be looked around from inside but as a supreme offer; aesthetical and rational conception of its space imposes exterior magnificence and proportional perfection. The Pantheon – Rome S II d C – represents a symbol of roman constructive project, that takes Greek formal vocabulary, combining it with its own constructive tradition based on the expansion of interior space and transforming architectonical elements into design rudiments. The first Saint Peter – Rome 324 d C – is an example ofmonumental building thought to house new Christian community, which space distribution is developed in only one direction and subordinated to the altar.O tratamento do interior nos edifícios de culto durante o período conhecido genéricamente como Antigüidade teve transformações cujos origens são tanto a participação da sociedade nos ritos sagrados quanto as diferentes tradições culturais sobre o espaço que foramse desenvolvendo nas etapas formativas da era. O Partenão – Atenas, s. V a.C – foi construído como casa e para honra de Atena, não pensado para ser percurso mas como máxima oferenda; a concepção estética e racional do espaço impôs magnificência exterior e perfeição proporcional. O Panteão – Roma, s. II d.C. – é um símbolo do projeto constructivo romano que uniu sua própria tradição constructiva, baseada na expansão do espaço interior, com o vocabulário formal grego, transformando os elementos arquitetônicos em elementos de seu desenho. A primeira Basílica de São Pedro – Roma, 324 d.C – é um exemplo de edificação monumental pensada para reunir à nova comunidade cristã, cuja distribução espacial unidireccional se subordina à presença do altar
The contribution of pattern recognition of seismic and morphostructural data to seismic hazard assessment
The reliable statistical characterization of the spatial and temporal
properties of large earthquakes occurrence is one of the most debated issues in
seismic hazard assessment, due to the unavoidably limited observations from
past events. We show that pattern recognition techniques, which are designed in
a formal and testable way, may provide significant space-time constraints about
impending strong earthquakes. This information, when combined with physically
sound methods for ground shaking computation, like the neo-deterministic
approach (NDSHA), may produce effectively preventive seismic hazard maps.
Pattern recognition analysis of morphostructural data provide quantitative and
systematic criteria for identifying the areas prone to the largest events,
taking into account a wide set of possible geophysical and geological data,
whilst the formal identification of precursory seismicity patterns (by means of
CN and M8S algorithms), duly validated by prospective testing, provides useful
constraints about impending strong earthquakes at the intermediate space-time
scale. According to a multi-scale approach, the information about the areas
where a strong earthquake is likely to occur can be effectively integrated with
different observations (e.g. geodetic and satellite data), including regional
scale modeling of the stress field variations and of the seismic ground
shaking, so as to identify a set of priority areas for detailed investigations
of short-term precursors at local scale and for microzonation studies. Results
from the pattern recognition of earthquake prone areas (M>=5.0) in the Po plain
(Northern Italy), as well as from prospective testing and validation of the
time-dependent NDSHA scenarios are presented.Comment: 33 pages, 7 Figures, 9 Tables. Submitted to Bollettino di Geofisica
Teorica e Applicata (BGTA
Unified Scaling Law for Earthquakes: Space-Time Dependent Assessment in Friuli-Venezia Giulia Region
The concept of the Unified Scaling Law for Earthquakes (USLE), which generalizes the Gutenberg-Richter relationship making use of the fractal distribution of earthquake sources in a seismic region, is applied to seismicity in the Friuli-Venezia Giulia region, FVG (Northeastern Italy) and its surroundings. In particular, the temporal variations of USLE coefficients are investigated, with the aim to get new insights in the evolving dynamics of seismicity within different tectonic domains of FVG. To this purpose, we consider all magnitude 2.0 or larger earthquakes that occurred in 1995–2019, as reported in the catalog compiled at the National Institute of Oceanography and Applied Geophysics (OGS catalog), within the territory of its homogeneous completeness. The observed variability of seismic dynamics for three sub-regions of the territory under investigation, delimited based on main geological and tectonic features, is characterized in terms of several moving averages, including: the inter-event time,τ; the cumulative Benioff strain release, Ʃ; the USLE coefficients estimated for moving six-years time intervals, and the USLE control parameter,η. We found that: 1) the USLE coefficients in FVG region are time-dependent and show up correlated; 2) the dynamical changes ofτ, Ʃ, andηin the three sub-regions highlight a number of different seismic regimes; 3) seismic dynamics, prior and after the occurrence of the 1998 and 2004 Kobarid (Slovenia) strong main shocks, is characterized by different parameters in the related sub-region. The results obtained for the FVG region confirm similar analysis performed on a global scale, in advance and after the largest earthquakes worldwide. Moreover, our analysis highlights the spatially heterogeneous and non-stationary features of seismicity in the investigated territory, thus suggesting the opportunity of resorting to time-dependent estimates for improving local seismic hazard assessment. The applied methods and obtained parameters provide quantitative basis for developing suitable models and forecasting tools, toward a better characterization of future seismic hazard in the region
The Park of Mataleñas (Santander): a heritage element of El Sardinero area
RESUMEN Desde finales del siglo XIX, la evolución de los balnearios de ola en El Sardinero y el atractivo excepcional que constituyeron los veraneos de la familia real generaron el florecimiento de actividades con la apuesta inversora de la burguesía, que procuró establecer un ambiente acorde a la estatura de la afluencia turística de élite. Ángel Pérez Eizaguirre contribuyó con el establecimiento de la Finca Valdenoja, como propiedad que conformara un entorno de belleza y exclusividad a ojos de su Majestad, de la aristocracia y demás visitas con poder político y económico. En este trabajo proponemos analizar aquel enclave, ahora transformado y reutilizado, a través de los distintos aspectos que lo erigen en testimonio de la iniciativa de sus propietarios, del talento de los profesionales que lo pergeñaron, y de un fenómeno social que originó edificios, infraestructuras y vínculos que marcaron la identidad de Santander; además de dar cuenta de su valor científico como espacio natural, actualmente al servicio de la comunidad. A través de este análisis de sus distintas facetas, intentamos propiciar su consideración como arquetipo de patrimonio tanto histórico como territorial, cuyo interés público estriba en variadas razones de índole paisajística, científica y ambiental que se suman a su condición de construcción cultural donde se manifiestan las características de la sociedad que propició su surgimiento.ABSTRACT Since the end of the 19th century, the evolution of the wave spas in El Sardinero and the exceptional appeal that the royal family's summers constituted, generated the flourishing of activities with the investment commitment of the bourgeoisie, which sought to establish an environment commensurate with stature of the elite tourist influx. Ángel Pérez Eizaguirre contributed to the establishment of Finca Valdenoja as a property that would create an environment of beauty and exclusivity in the eyes of his Majesty, the aristocracy and other visitors with political and economic power. In this work we try to analyze that enclave, now transformed and reused, through the different aspects that make it a testimony to the initiative of its owners, the talent of the professionals who designed it, and a social phenomenon that originated buildings, infrastructures and links that marked the identity of Santander; in addition to giving an account of its scientific value as a natural space, currently at the service of the community. Through this analysis of its different facets, we try to promote its consideration as anarchetype of both historical and territorial heritage, whose public interest lies in various reasons of a landscape, scientific and environmental nature that add to its condition of cultural construction where the characteristics of the society that led to its emergence are manifested.Máster en Patrimonio Histórico y Territoria
Los tejidos biológicos : una entidad compleja. Desde la investigación científica a la transposición didáctica
En los ambientes educativos se observa con frecuencia ausencia de claridad entre los niveles de organización de la materia viva, en especial en el recorte que atañe células, tejidos y órganos. Es usual la falta de discernimiento teórico y la imposibilidad de identificación visual del nivel tisular en las prácticas de laboratorio de los estudiantes. Al revisar la historia de la ciencia encontramos notables disensos en algunas de esas concepciones, entre las que aún persiste la que corresponde a tejidos. Creemos importante explorar la diversidad conceptual que acompaña el avance de las investigaciones científicas y arribar a una noción intersubjetivamente funcional, no solo para los científicos en actividad sino también para ampliar los horizontes académicos al resignificar los niveles de organización y sus componentes desde un enfoque sistémico e integrador
Neo-deterministic seismic hazard scenarios for India—a preventive tool for disaster mitigation.
Current computational resources and physical knowledge of the seismic wave generation and propagation processes allow for reliable numerical and analytical models of waveform generation and propagation. From the simulation of ground motion, it is easy to extract the desired earthquake hazard parameters. Accordingly, a scenario-based approach to seismic hazard assessment has been developed, namely the neo-deterministic seismic hazard assessment (NDSHA), which allows for a wide range of possible seismic sources to be used in the definition of reliable scenarios by means of realistic waveforms modelling. Such reliable and comprehensive characterization of expected earthquake ground motion is essential to improve building codes, particularly for the protection of critical infrastructures and for land use planning. Parvez et al. (Geophys J Int 155:489–508, 2003) published the first ever neo-deterministic seismic hazard map of India by computing synthetic seismograms with input data set consisting of structural models, seismogenic zones, focal mechanisms and earthquake catalogues. As described in Panza et al. (Adv Geophys 53:93–165, 2012), the NDSHA methodology evolved with respect to the original formulation used by Parvez et al. (Geophys J Int 155:489–508, 2003): the computer codes were improved to better fit the need of producing realistic ground shaking maps and ground shaking scenarios, at different scale levels, exploiting the most significant pertinent progresses in data acquisition and modelling. Accordingly, the present study supplies a revised NDSHA map for India. The seismic hazard, expressed in terms of maximum displacement (Dmax), maximum velocity (Vmax) and design ground acceleration (DGA), has been extracted from the synthetic signals and mapped on a regular grid over the studied territory
Crowd-Sourced Buildings Data Collection and Remote Training: New Opportunities to Engage Students in Seismic Risk Reduction
Young generations are increasingly committed to understanding disasters, and are a key player in current and future disaster risk reduction activities. The availability of online tools opened new perspectives in the organization of risk-related educational activities, in particular in earthquake-prone areas. This is the case of CEDAS (building CEnsus for seismic Damage Assessment), a pilot training activity aimed at collecting risk-related information while educating high-school students about seismic risk. During this experimental activity, students collected and elaborated crowdsourced data on the main building typologies in the proximity of their homes. In a few months, students created a dataset of valuable risk-related information, while getting familiar with the area where they live. Data collection was performed both on-site, using smartphones, and online, based on remote sensing images provided by multiple sources (e.g., Google maps and street view). This allowed all students, including those with limited mobility, to perform the activity. The CEDAS experience pointed out the potential of online tools and remote sensing images, combined with practical activities and basic training in exploratory data analysis, to engage students in an inclusive way. The proposed approach can be naturally expanded in a multi-risk perspective, and can be adjusted, eventually increasing the technical content of collected information, to the specific training and expertise of the involved students, from high-school to university level
CLIMATIC MODULATION OF SEISMICITY IN THE ALPINE-HIMALAYAN MOUNTAIN RANGE
Abstract The influence of strain field variations associated with seasonal and longer term climatic phenomena on earthquake occurrence is investigated. Two regions (Himalaya and Alps), characterized by present day mountain building and relevant glaciers retreat, as well as by sufficiently long earthquake catalogues, are suitable for the analysis. Secular variations of permanent glaciers dimensions, which are naturally grossly correlated with long-term average surface atmosphere temperature changes, as well as seasonal snow load, cause crustal deformations that modulate seismicity. MIRAMARE -TRIESTE April 2009 2 Introduction Tectonic forces responsible for mountain building must overcome, among others, gravity force
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