72 documents found, page 1 of 8
Muography Applied in Underground Geological Surveys: Ongoing Work at the Lousal...
Teixeira, Pedro; Blanco, Alberto; Caldeira, Bento; Tomé, Bernardo; Alexandre, Isabel; Matos, João; Silva, Jorge; Borges, José; Cazon, LorenzoThe LouMu Project is an ongoing collaboration between the Laboratory of Instrumentation and Experimental Particle Physics (LIP), the Institute of Earth Sciences—University of Évora and the Lousal Ciência Viva Center which is evaluating the muography potential in the Lousal Mine, with the general aim to create the conditions to use muography as a novel method for geophysical surveys in Portugal. The National Lab...
Muon tomography with Resistive Plate Chambers for geological characterization
Sarmento, Raul; Castro, Alberto Blanco; Caldeira, Bento; Tomé, Bernardo; Loureiro, Custódio; Clemêncio, Filomena; Costa, João; Matos, JoãoMuon tomography is one of several fields of applied physics that have witnessed the successful use of particle detection based on Resistive Plate Chambers (RPC). In this work, we report on an innovative project concerning transmission muography for geological characterization. For this purpose, a muon telescope built of four RPC planes was mounted on an adjustable structure and the telescope's response to atmos...
Local Seismic Tomography Reveals the Crustal Structure Beneath Arraiolos (Centr...
Hamak, Ines; Wachilala, Piedade; Borges, José; Koulakov, Ivan; Araújo, Alexandre; Bezzeghoud, MouradAn ML 4.9 earthquake occurred in Arraiolos, central Alentejo, on the 15 January 2018. As the mainshock was recorded as the highest magnitude in the region, a thorough investigation of the cause of this seismicity was carried out. In this study, local seismic tomography was conducted for the first time to demonstrate the importance of a uniform spatial distribution of earthquakes for obtaining accurate crustal i...
Depth estimation of pre-Kalahari basement in Southern Angola using seismic nois...
Carvalho, João; Alves, Daniela; Borges, José; Caldeira, Bento; Cordeiro, D.The remote Southern region of Angola is covered by siliciclastic Kalahari Cenozoic formations that host un- derground aquifers of great importance to local populations affected by water scarcity problems. These aquifers are well developed where Kalahari sands reach appropriate thicknesses. On the other hand, at the eastern end of this area, regional aeromagnetic data recently acquired suggested the possibility ...
Soil Classification Maps for the Lower Tagus Valley Area, Portugal, Using Seism...
Carvalho, João; Dias, Ruben; Borges, José; Quental, Lidia; Caldeira, BentoThe Lower Tagus Valley (LTV) region has the highest population density in Portugal, with over 3.7 million people living in the region. It has been struck in the past by several historical earthquakes, which caused significant economic and human losses. For a proper seismic hazard evaluation, the area needs detailed Vs30 and soil classification maps. Previously available maps are based on proxies, or an insuffic...
Seismic Sequence Analysis of the Arraiolos Zone, South Portugal, and Its Seismo...
Wachilala, Piedade; Borges, José; Caldeira, Bento; Bezzeghoud, MouradThe Arraiolos Zone has been affected by the persistent superficial seismicity (focal depth < 20 km) of a weak magnitude (M < 4) and some events of a higher magnitude (M > 4), and is mainly located around the Aldeia da Serra village. On 15 January 2018, at 11:51 UTC, the largest instrumental earthquake recorded in that area occurred, with a magnitude (ML 4.9) located northeast of Arraiolos, near the Aldeia da Se...
Source parameters of the moderate‐sized (ML 4.9) 2018 Arraiolos, Portugal earth...
Wachilala, Piedade; Borges, José; Caldeira, Bento; Bezzeghoud, MouradThe Arraiolos zone is one of the most seismically active intraplate regions in mainland Portugal and is characterized by low- to moder- ate-magnitude events. However, there is a need to analyse the characteristics of the seismic source parameters in this zone, which is crucial for under- standing the origin of the zone’s seismicity and gaining insights into the stresses involved in the rupture processes of seis...
FONTE DO SISMO DE MARROCOS DE 2023 (MW6.8) INFERIDA A PARTIR DO CRUZAMENTO DE D...
Caldeira, Bento; Bezzeghoud, Mourad; Oliveira, Rui; Borges, José; Hamak, Ines; Buforn, ElisaOn September 8, 2023, at 22:11 UTC, an earthquake of magnitude 6.8 with epicenter near the village of Talat N'Yaaqoub, province of Al Haouz (Morocco), High Atlas region, shook violently the entire epicentral zone within a radius of more of 70km, seriously affecting the structures of more than 78,000 buildings and causing approximately 5,600 injuries and around 3,000 fatalities. This work presents part of the de...
GEOLOGICAL CHARACTERIZATION OF CO2 STORAGE COMPLEXES INTEGRATING AUTOCORRELATIO...
Caeiro, Maria Helena; Vieira, João; Moreno, Beatriz; Pereira, Pedro; Caldeira, Bento; Ribeiro, Carlos; Borges, José; Canteli, Paula; Oliveira, RuiThe PilotSTRATEGY project investigates geological carbon dioxide (CO₂) storage in deep saline aquifers, focusing on the Monte Real site in Portugal. Due to limited well and seismic data, passive seismic methods were used for cost-effective and environmentally friendly subsurface characterization. The study involved recording ambient noise, analyzing it through autocorrelation, and comparing with existing seismi...
Increasing the Lateral Resolution of 3D-GPR Datasets through 2D-FFT Interpolati...
Oliveira, Rui; Caldeira, Bento; Teixidó, Teresa; Borges, José; Carneiro, AndréThe approach presented in this work uses an interpolation methodology to densify 3D-GPR datasets to sharpen the results obtained in GPR surveys carried out in an archaeological environment. It allows the estimation of missing data from the combined use of mathematical transforms, such as the Fourier and curvelet transforms, and predictive filters. This technique makes it possible to calculate the missing signal...