Liquefaction Hazard Evaluation for a 3rd Level Microzonation Study in a High Seismicity Area of Central Italy

2019 ◽  
pp. 348-357
Author(s):  
J. Facciorusso ◽  
C. Madiai ◽  
G. Vannucchi ◽  
E. Gargini ◽  
M. Baglione
Keyword(s):  
Central Italy ◽  
Hazard Evaluation ◽  
Liquefaction Hazard ◽  
High Seismicity

scholarly journals An automatically generated high-resolution earthquake catalogue for the 2016–2017 Central Italy seismic sequence, including P and S phase arrival times

2020 ◽  
Author(s):  
D Spallarossa ◽  
M Cattaneo ◽  
D Scafidi ◽  
M Michele ◽  
L Chiaraluce ◽  
...  
Keyword(s):  
Real Time ◽  
Central Italy ◽  
Earthquake Catalogue ◽  
Hazard Evaluation ◽  
Depth Range ◽  
Data Set ◽  
Epicentral Area ◽  
Earthquake Parameters ◽  
Waveform Data ◽  
Arrival Times

Summary The 2016–17 central Italy earthquake sequence began with the first mainshock near the town of Amatrice on August 24 (MW 6.0), and was followed by two subsequent large events near Visso on October 26 (MW 5.9) and Norcia on October 30 (MW 6.5), plus a cluster of 4 events with MW > 5.0 within few hours on January 18, 2017. The affected area had been monitored before the sequence started by the permanent Italian National Seismic Network (RSNC), and was enhanced during the sequence by temporary stations deployed by the National Institute of Geophysics and Volcanology and the British Geological Survey. By the middle of September, there was a dense network of 155 stations, with a mean separation in the epicentral area of 6–10 km, comparable to the most likely earthquake depth range in the region. This network configuration was kept stable for an entire year, producing 2.5 TB of continuous waveform recordings. Here we describe how this data was used to develop a large and comprehensive earthquake catalogue using the Complete Automatic Seismic Processor (CASP) procedure. This procedure detected more than 450,000 events in the year following the first mainshock, and determined their phase arrival times through an advanced picker engine (RSNI-Picker2), producing a set of about 7 million P- and 10 million S-wave arrival times. These were then used to locate the events using a non-linear location (NLL) algorithm, a 1D velocity model calibrated for the area, and station corrections and then to compute their local magnitudes (ML). The procedure was validated by comparison of the derived data for phase picks and earthquake parameters with a handpicked reference catalogue (hereinafter referred to as ‘RefCat’). The automated procedure takes less than 12 hours on an Intel Core-i7 workstation to analyse the primary waveform data and to detect and locate 3000 events on the most seismically active day of the sequence. This proves the concept that the CASP algorithm can provide effectively real-time data for input into daily operational earthquake forecasts, The results show that there have been significant improvements compared to RefCat obtained in the same period using manual phase picks. The number of detected and located events is higher (from 84,401 to 450,000), the magnitude of completeness is lower (from ML 1.4 to 0.6), and also the number of phase picks is greater with an average number of 72 picked arrival for a ML = 1.4 compared with 30 phases for RefCat using manual phase picking. These propagate into formal uncertainties of ± 0.9km in epicentral location and ± 1.5km in depth for the enhanced catalogue for the vast majority of the events. Together, these provide a significant improvement in the resolution of fine structures such as local planar structures and clusters, in particular the identification of shallow events occurring in parts of the crust previously thought to be inactive. The lower completeness magnitude provides a rich data set for development and testing of analysis techniques of seismic sequences evolution, including real-time, operational monitoring of b-value, time-dependent hazard evaluation and aftershock forecasting.

The “CO2-rich gas vents” of Mt. Amiata volcano (Tuscany, Central Italy): Geochemistry, genetic mechanism and hazard evaluation

2006 ◽  
Vol 25 (S1) ◽  
pp. 70-71
Author(s):  
Franco Tassi ◽  
Orlando Vaselli ◽  
Elena Lognoli ◽  
Fabrizio Cuccoli ◽  
Barbara Nisi ◽  
...  
Keyword(s):  
Central Italy ◽  
Genetic Mechanism ◽  
Hazard Evaluation

Landslide hazard evaluation: a review of current techniques and their application in a multi-scale study, Central Italy

Geomorphology ◽  
1999 ◽  
Vol 31 (1-4) ◽  
pp. 181-216 ◽  
Author(s):  
Fausto Guzzetti ◽  
Alberto Carrara ◽  
Mauro Cardinali ◽  
Paola Reichenbach
Keyword(s):  
Central Italy ◽  
Landslide Hazard ◽  
Hazard Evaluation ◽  
Multi Scale

Intensity measures for seismic liquefaction hazard evaluation of sloping site

2015 ◽  
Vol 22 (10) ◽  
pp. 3999-4018 ◽  
Author(s):  
Zhi-xiong Chen ◽  
Yin Cheng ◽  
Yang Xiao ◽  
Liang Lu ◽  
Yang Yang
Keyword(s):  
Hazard Evaluation ◽  
Intensity Measures ◽  
Seismic Liquefaction ◽  
Liquefaction Hazard

Liquefaction hazard evaluation by Swedish weight sounding test

2020 ◽  
pp. 337-342
Author(s):  
J. Kuwano ◽  
K. Ogawa ◽  
T. Kimura ◽  
H. Aoki
Keyword(s):  
Hazard Evaluation ◽  
Liquefaction Hazard

Ground Motion Intensity Measures for Liquefaction Hazard Evaluation

2006 ◽  
Vol 22 (2) ◽  
pp. 413-438 ◽  
Author(s):  
Steven L. Kramer ◽  
Robert A. Mitchell
Keyword(s):  
Ground Motion ◽  
Earthquake Engineering ◽  
Ground Motions ◽  
Excess Pore Pressure ◽  
Hazard Evaluation ◽  
Peak Acceleration ◽  
Intensity Measure ◽  
Arias Intensity ◽  
Intensity Measures ◽  
Liquefaction Hazard

The requirements of performance-based earthquake engineering place increasing importance on the optimal characterization of earthquake ground motions. With respect to liquefaction hazard evaluation, ground motions have historically been characterized by a combination of peak acceleration and earthquake magnitude, and more recently by Arias intensity. This paper introduces a new ground motion intensity measure, CAV5, and shows that excess pore pressure generation in potentially liquefiable soils is considerably more closely related to CAV5 than to other intensity measures, including peak acceleration and Arias intensity. CAV5 is shown to be an efficient, sufficient, and predictable intensity measure for rock motions used as input to liquefaction hazard evaluations. An attenuation relationship for CAV5 is presented and used in an example that illustrates the benefits of scaling bedrock motions to a particular value of CAV5, rather than to the historical intensity measures, for performance-based evaluation of liquefaction hazards.

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