Fernando Carlos Lopes

Incorporating Descriptive Metadata into Seismic Source Zone Models for Seismic-Hazard Assessment: A Case Study of the Azores-West Iberian Region

In probabilistic seismic-hazard analysis (PSHA), seismic source zone (SSZ) models are widely used to account for the contribution to the hazard from earth- quakes not directly correlated with geological structures. Notwithstanding the impact of SSZ models in PSHA, the theoretical framework underlying SSZ models and the criteria used to delineate the SSZs are seldom explicitly stated and suitably docu- mented. In this paper, we propose a methodological framework to develop and docu- ment SSZ models, which includes (1) an assessment of the appropriate scale and degree of stationarity, (2) an assessment of seismicity catalog completeness-related issues, and (3) an evaluation and credibility ranking of physical criteria used to delin- eate the boundaries of the SSZs. We also emphasize the need for SSZ models to be supported by a comprehensive set of metadata documenting both the unique character- istics of each SSZ and the criteria used to delineate its boundaries. This procedure ensures that the uncertainties in the model can be properly addressed in the PSHA and that the model can be easily updated whenever new data are available. The pro- posed methodology is illustrated using the SSZ model developed for the Azores-West Iberian region in the context of the Seismic Hazard Harmonization in Europe project (project SHARE) and some of the most relevant SSZs are discussed in detail. Online Material: Tables describing characteristics and boundaries of the seismic source zones.

Educating for earthquake science and risk in a tectonically slowly deforming region

Over the past decade, scientists have been called to participate more actively in public education and outreach (E&O). This is particularly true in fields of significant societal impact, such as earthquake science. Local earthquake risk culture plays a role in the way that the public engages in educational efforts. In this article, we describe an adapted E&O program for earthquake science and risk. The program is tailored for a region of slow tectonic deformation, where large earthquakes are extreme events that occur with long return periods. The adapted program has two main goals: (1) to increase the awareness and preparedness of the population to earthquake and related risks (tsunami, liquefaction, fires, etc.), and (2) to increase the quality of earthquake science education, so as to attract talented students to geosciences. Our integrated program relies on activities tuned for different population groups who have different interests and abilities, namely young children, teenagers, young adults, and professionals.

Mapping of salt structures and related fault lineaments based on remote-sensing and gravimetric data: The case of the Monte Real salt wall (onshore west-central Portugal)

The Monte Real (MR) salt wall (MR structure) is a salt structure located in the Monte Real–Pombal Subbasin (onshore west-central Portugal). The MR structure was emplaced during post–Triassic–Mesozoic extensional and Tertiary compressional tectonics and is now partially buried under Miocene to Pliocene–Pleistocene sediments. The region is dominated by NS 20, N45 10E, N30 10W, and N70 10W trending main tectonic systems. Remote-sensing data constrained by gravimetric data allowed the recognition of the two-dimensional surface geometry of this salt structure and its associated structural features. The use of remote-sensing images (optical and microwave data) allow mapping the MR structure based on the heat radiated from rocks and soils, changes in vegetation cover, and texture analysis of synthetic aperture radar imagery. In addition, remote-sensing data, combined with modeled topographic data, also allowed recognition of a lineament pattern consistent with the fracture pattern of the region, probably related to the implantation and deformation of this salt body. The crosscut behavior of the identified structural lineaments can justify the north-northwestern elongated arcuate shape of the MR structure and the corresponding gravimetric anomaly. This work shows that remote-sensing techniques are a powerful tool to study buried salt domes even in the absence of detailed geophysical data.

Recognizing salt-structures on the basis of geophysical and remote sensing data: the case of monte real salt-structure (onshore west-central portugal)

Remote sensing data from Monte Real sub-basin (onshore West-Central Portugal), collected by the LANDSAT 7 ETM+, JERS-1 (SAR) and Envisat (ASAR) satellites, are used with the purpose to give new insights relatively to the Monte Real salt-structure. The recognized pattern of the diapir and of the structural lineaments is in agreement with the geophysical and geological data.