Laboratory characterization of hydromechanical properties of a seismogenic normal fault system

1998 ◽  
Vol 20 (7) ◽  
pp. 865-881 ◽  
Author(s):  
Bernard Seront ◽  
Teng-Fong Wong ◽  
Jonathan S. Caine ◽  
Craig B. Forster ◽  
Ronald L. Bruhn ◽  
...  
Keyword(s):  
Normal Fault ◽  
Fault System ◽  
Laboratory Characterization

scholarly journals Workflow of Digital Field Mapping and Drone-Aided Survey for the Identification and Characterization of Capable Faults: The Case of a Normal Fault System in the Monte Nerone Area (Northern Apennines, Italy)

2020 ◽  
Vol 9 (11) ◽  
pp. 616
Author(s):  
Mauro De Donatis ◽  
Mauro Alberti ◽  
Mattia Cipicchia ◽  
Nelson Muñoz Guerrero ◽  
Giulio F. Pappafico ◽  
...  
Keyword(s):  
Central Italy ◽  
Three Dimensional ◽  
Normal Fault ◽  
Field Work ◽  
Digital Data ◽  
Fault System ◽  
Seismic Profiles ◽  
Postgraduate Students ◽  
Recent Earthquakes

Field work on the search and characterization of ground effects of a historical earthquake (i.e., the Cagli earthquake in 1781) was carried out using terrestrial and aerial digital tools. The method of capturing, organizing, storing, and elaborating digital data is described herein, proposing a possible workflow starting from pre-field project organization, through reiteration of field and intermediate laboratory work, to final interpretation and synthesis. The case of one of the most important seismic events in the area of the northern Umbria–Marche Apennines provided the opportunity to test the method with both postgraduate students and researchers. The main result of this work was the mapping of a capable normal fault system with a great number of observations, as well as a large amount of data, from difficult outcrop areas. A GIS map and a three-dimensional (3D) model, with the integration of subsurface data (i.e., seismic profiles and recent earthquake distribution information), allowed for a new interpretation of an extensional tectonic regime of this Apennines sector, similar to one of the southernmost areas of central Italy where recent earthquakes occurred on 2016.

scholarly journals Preliminary geochemical characterization of gas manifestations in North Macedonia

2020 ◽  
Author(s):  
Marjan Temovski ◽  
Walter D’Alessandro ◽  
Artur Ionescu ◽  
Lorenza Li Vigni ◽  
Kata Molnár ◽  
...  
Keyword(s):  
Isotope Composition ◽  
Normal Fault ◽  
Balkan Peninsula ◽  
Fault System ◽  
Geochemical Characterization ◽  
Three Samples ◽  
Crustal Contribution ◽  
Main Component ◽  
Pleistocene Volcanism

<p>Like most of the Balkan Peninsula, North Macedonia is a geodynamically active area. As such it has many hydrothermal features and gas manifestations. Until now, no systematic study about the geochemical characterization of the geogenic gases was made before in this country. In August 2019, 24 gas samples were collected in the study area. All, except one collected at Duvalo (soil gas), are gases bubbling or dissolved in thermomineral waters (temperatures from 12 to 66 °C). They were analysed in the laboratory for their chemical (He, Ne, Ar, O<sub>2</sub> , N<sub>2</sub> , H<sub>2</sub> , H<sub>2</sub>S, CH<sub>4</sub> and CO<sub>2</sub>) and isotopic composition (δ<sup>13</sup>C-CO<sub>2</sub>, δ<sup>13</sup>C-CH<sub>4</sub>, δ<sup>2</sup>H-CH<sub>4</sub> and R/R<sub>A</sub>). Most of the gases have CO<sub>2</sub> as the main component (400-998,000 ppm) while the remaining are enriched in N<sub>2</sub> (1300-950,000 ppm). Helium ranges from 0.3 to 2560 ppm while CH<sub>4</sub> from 1.6 to 20,200 ppm. R/R<sub>A</sub> and <sup>4</sup>He/<sup>20</sup>Ne ratios indicate a generally low atmospheric contamination, a prevailing crustal contribution and mantle contributions between 1 and 20% considering a MORB endmember. The highest mantle contributions are found in the SE part of the country very close to the sites that show the highest R/R<sub>A</sub> values in continental Greece [1]. This area is characterised by extensional tectonics and Plio-Pleistocene volcanism. A quite high mantle contribution (about 15%) is also found in two manifestations in the NW part of the country along a main normal fault system. With the exception of the sample of Smokvica, which has very low CO<sub>2</sub> (1400 ppm) and δ<sup>13</sup>C-CO<sub>2</sub> (-15.7 ‰ V-PDB), all free gases show a relatively narrow range in δ<sup>13</sup>C-CO<sub>2</sub> values (-4.6 to +1.0 ‰ V-PDB) indicating the mixing between a mantle and a carbonate rock source. The isotope composition allows us to assign the CH<sub>4</sub> origin to three sources. The largest group can be attributed to a hydrothermal origin (δ<sup>13</sup>C-CH<sub>4</sub> around -20 ‰ V-PDB and δ<sup>2</sup>H-CH<sub>4</sub> around -100‰). Three samples collected in the SW part of the country have a thermogenic origin (δ<sup>13</sup>C-CH<sub>4</sub> around -35 ‰ V-PDB and δ<sup>2</sup>H-CH<sub>4</sub> around -160‰ V-SMOW). Finally, one sample (Smokvica) with the highest values (δ<sup>13</sup>C-CH<sub>4</sub> -7.2 ‰ V-PDB and δ<sup>2</sup>H-CH<sub>4</sub> -80‰ V-SMOW) may be attributed to abiotic processes in a continental serpentinization environment or to methane oxidation.</p><p>This research was funded by the DCO Grant n. 10881-TDB “Improving the estimation of tectonic carbon flux”, GINOP-2.3.2-15-2016-00009 ‘ICER’ project and PO FSE Sicilia 2014 – 2020 (CUP: G77B17000200009).</p><p>References:</p><p>[1] Daskalopoulou et al., 2018 – Chemical Geology, 479, 286-301</p>

Laboratory Characterization of SAM-35 Concrete

2006 ◽  
Author(s):  
Erin M. Williams ◽  
Stephen A. Akers ◽  
Paul A. Reed
Keyword(s):  
Laboratory Characterization

Laboratory characterization of an APD-based tip-tilt corrector

1997 ◽  
Author(s):  
Simone Esposito ◽  
Enrico Marchetti ◽  
Roberto Ragazzoni ◽  
Andrea Baruffolo ◽  
Jacopo Farinato ◽  
...  
Keyword(s):  
Laboratory Characterization

scholarly journals Insights into Mechanical Properties of the 1980 Irpinia Fault System from the Analysis of a Seismic Sequence

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 28
Author(s):  
Gaetano Festa ◽  
Guido Maria Adinolfi ◽  
Alessandro Caruso ◽  
Simona Colombelli ◽  
Grazia De Landro ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Early Warning Systems ◽  
Fault System ◽  
Minimum Size ◽  
Double Difference ◽  
Warning Systems ◽  
Initiation Mechanism ◽  
Earthquake Early Warning Systems ◽  
The One

Seismic sequences are a powerful tool to locally infer geometrical and mechanical properties of faults and fault systems. In this study, we provided detailed location and characterization of events of the 3–7 July 2020 Irpinia sequence (southern Italy) that occurred at the northern tip of the main segment that ruptured during the 1980 Irpinia earthquake. Using an autocorrelation technique, we detected more than 340 events within the sequence, with local magnitude ranging between −0.5 and 3.0. We thus provided double difference locations, source parameter estimation, and focal mechanisms determination for the largest quality events. We found that the sequence ruptured an asperity with a size of about 800 m, along a fault structure having a strike compatible with the one of the main segments of the 1980 Irpinia earthquake, and a dip of 50–55° at depth of 10.5–12 km and 60–65° at shallower depths (7.5–9 km). Low stress drop release (average of 0.64 MPa) indicates a fluid-driven initiation mechanism of the sequence. We also evaluated the performance of the earthquake early warning systems running in real-time during the sequence, retrieving a minimum size for the blind zone in the area of about 15 km.

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