A Quantitative Evaluation Method for Nonstationarity of Training Image Based on Pattern Tiles Distance

An a priori model for multipoint statistics (MPS) modeling approaches is a training image. Before using MPS modeling, it must be determined whether the training images satisfy the spatial statistical stationarity. Modeling can be performed using the regular MPS approach if a training image is stationary. Otherwise, an enhanced method of nonstationary modeling is required. For instance, partition-based nonstationary modeling is an option. This study proposes a nonstationary evaluation metric based on pattern tile distances. It is possible to more accurately quantify the characteristics of the various distributions of spatial structure features in the entire space and achieve the goal of quantitatively evaluating the nonstationary metrics of training images by quantifying the distances of lower-level subpatterns in the pattern. Furthermore, an automatic partitioning approach based on pattern tile discrepancy is proposed for nonstationary training images to avoid the subjective and inefficient issues of manual partitioning when the training images cannot meet the stationary requirement of MPS modeling

SEISMIC VULNERABILITY OF SHALLOW UNDERGROUND CAVITIES IN SOFT ROCK

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Site Amplifications in the epicentral area of the 2016, M 6, Amatrice earthquake (Italy)

The first mainshock (Mw 6.0) of the 2016 Central Italy seismic sequence, severely struck the Amatrice village and the surrounding localities. After a few days, some Italian Institutions, coordinated by the “Center for Seismic Microzonation and its applications”, carried out several preparatory activities for seismic microzonation of the area. A temporary seismic network was installed that monitored about 50 sites in epicentral area. The network produced a huge amount of records in a wide range of magnitude up to Mw 6.5. For about half of the recording stations, detailed site characterization was undertaken, encompassing single station noise measurements and S-wave velocity profiles. The geological and geophysical data together with the collected dataset of seismic signals were exploited to investigate the site response of selected stations. Significant amplifications are found in the correspondence of several sites that experienced a high level of damage (Imcs >IX), mainly at short and intermediate periodsPublishedRoma5T. Sismologia, geofisica e geologia per l'ingegneria sismic

The Laga Basin: Stratigraphic and Structural Setting. Geological Field trip.

The field trip area comprises one of the most studied syn-orogenic basins of Apennines, developed during Messinian time: the Laga Basin. Due to the period of its geological evolution, it represents a link between the internal, uplifted, Lower Miocene fold-and-thrust-belt of the Apennines in the west and the external and more recent part of the chain buried below a thick pile of syn-orogenic, Plio-Pleistocene clastic deposits, in the east. The Laga basin is filled by siliciclastic sedimentary succession which indicates a general eastward migration of the depositional systems, strongly control by thrusting. The basin is the footwall of two regional thrusts cropping out respectively to the west and to the south: the Mts. Sibillini thrust (trending SE-NE) and the Gran Sasso thrust (trending E-W). Other thrust-related-anticlines, trending N-S, developed in the basin during Messinian, are characterized by high angle thrust planes and reduced amount of shortening. The geometric and chronological relationship between the N-S and E-W trending structures is one of the most debated topics regarding this area. The contractional structural building is offset by Upper Pliocene – Pleistocene normal faults, that border the main quaternary basins in the area. The focus of the field trip will be upon the structural and stratigraphic setting of the basin. The stratigraphic architecture of the Laga deposits will be analyzed through some key outcrops (about five or six stops), where is possible to see the main sedimentological features of the different depositional environments. The geometric setting of the Laga deposits with respect to the growing anticlines, the regional monocline and the Gran Sasso thrust will be also shown. Afterward, moving southward, attendees will be given a tour following a section across the Gran Sasso thrust, which includes (in about 4 stops): i) the younger Pliocene deposits that post-dated the main deformation of this regional thrust (Rigopiano Conglomerate Fm in angular unconformity on the Gran Sasso unit); ii) the relationships between the contractional structure and the younger extensional normal faults (Campo Imperatore)

Facies and architecture of the Lower Messinian turbidite lobe complexes from the Laga Basin (central Apennines, Italy)

Turbidite depositional lobes are the main architectural element of many ancient turbidite systems. On modern submarine fans, they constitute sandy accumulations with lobate planform forming as terminal splays at channel mouths. Several outcrop, marine geology and experimental studies have documented how facies, depositional geometries, and overall architecture of turbidite depositional lobes can be largely controlled by the host basin morphology. This study investigates the architecture of turbidite lobe complexes from the Southern Laga Basin (SLB; central Apennines, Italy) basing on detailed bed-by-bed correlations. During the Early Messinian, the SLB was part of a quickly deforming sector of the Apennine foreland basin system and hosted the deposition of a thick turbidite succession. The SLB's size and morphology were controlled by the balance of tectonics and sedimentation. In such a context, SLB's depositional lobes were topographically confined in an N-S trending dead-end trough delimited by thrust-related anticlines. Eventually, as turbidite sedimentation progressively smoothed out the seafloor morphology up to allow depositional lobes spilled to the E over the more external anticline.. Strike and dip sections across depositional lobes on an approximately 1700 m thick interval from the SLB's Lower Messinian, enabled us to describe and compare the depositional architecture of turbidite complexes with different degree of basin confinement. Three main lobe sub-settings were recognized: i) a channel-lobe transition sector, where through-cross bedded and massive-to-crudely laminated beds form composite sandstone bodies which thicken down current; ii) a proximal lobe sector, where crudely laminated to planar-parallel laminated medium-fine sandstones constitute amalgamated to non amalgamated beds thinning out relatively rapidly down and across current; iii) an intermediate to distal (lobe fringe) sector characterized by deposition of thin-bedded turbidites, occasionally intercalated by debris-flow and slumping deposits. The comparison of depositional shapes revealed the dependency of sandstone body lenticularity on thickness (and, imlplicitly, depositional hierarchy), lobe sub-setting and degree of topographic confinement. At a higher hierarchical scale, the role of topographic confinement was even more important and brougth about two distinctive architectures of lobe complex. Confined stratigraphic complexes show a sheet-like architecture where compensation process is unimportant and lobes gently pinch and shale out toward basin margins, whilst unconfined ones are characterized by compensational stacking of lobes and a rather intricate facies distribution. Finally, the basin-fill scale architecture of SLB lobes was controlled by the interplay of thrusting and turbidite sedimentation, which modulated the degree of topographic confinement and caused the progressive eastward shift of the depocentre