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The 28th September 2018 Sulawesi Supershear earthquake (M W 7.5) was one of the deadliest earthquakes in the recent history of Indonesia causing ∼4000 causalities. The earthquake caused a ∼ 177 km long surface rupture along the Palu-Karo fault. Apart from surface rupture, the earthquake caused extensive earthquake environmental effects (EEEs) around the Palu-Donggala area of Central Sulawesi, Indonesia, which includes tsunami, coastal landslide, liquefaction, ground cracks and more than 7300 landslides in hilly areas. Initial post-event analysis and reports assigned a Modified Mercalli Intensity (MMI) of VII to VIII in Palu City and the surrounding area. Building damage and ground effects caused by the earthquake suggested that seismic intensity was understated. Here we applied the EEEs information from field survey data, published reports, and remote sensing tools to determine macroseismic intensity using the Environmental Seismic Intensity (ESI-07) Scale. The ESI-07 intensity derived from the ground effects suggests the maximum intensity of X-XI, which is 3–4° higher than the traditional intensity estimated by the United States Geological Survey (USGS) and the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG). ShakeMaps were generated considering the ESI-07 values. The ShakeMap was compared with the instrumentally derived ShakeMap for the Palu earthquake, which proves that the ShakeMap prepared from the instrumental data or structural damage data is underrated. We argue that proper documentation of the EEEs is necessary for such damaging earthquakes for future earthquake hazard mapping and planning in the study area and other earthquakes in Indonesia. In addition, this will help in defining the on-fault and off-fault damage zone towards reducing the seismic risk of the Palu Donggala area. • Detailed Earthquake Environmental Effects (EEEs) caused by the 28/09/2018 Sulawesi earthquake (M w 7.5) were collected. • The epicentral ESI-07 intensity as well as the site specific intensity were estimated. • The ESI-07 intensity were compared with Skala Intensitas Gempabhumi (SIG), BMKG. • ESI-07 ShakeMap were generated using the Surface Rupture data and ESI-07 values. • The maps can be used to guide efficient and strategic seismic hazard assessment and land use planning. [ABSTRACT FROM AUTHOR]

On 17 November 2016, an unexpected slope failure occurred in an undisclosed copper open-pit mine. The nature of the event urged for a thorough back-analysis of slope monitoring data in order to assess its size and temporal evolution, and to determine whether precursors potentially able to anticipate the failure were present. To this aim, satellite InSAR data spanning over the final 9 months before the event were, in retrospect, acquired and coupled with measurements from a ground-based radar that was in use at the time of the failure. Although progressive deformation was detected by the ground-based radar in correspondence of the two uppermost benches in the pit, the satellite InSAR data revealed that the vast majority of the instability actually involved a large part of natural slope above the mine crest. This sector was not visible by the ground-based radar. Thanks to the short revisit time of the Sentinel-1 mission, clear slope accelerating creep was observed for the first time in satellite InSAR measurements over an open-pit mine. The delimitation of the area featuring accelerating creep behavior matched remarkably the source area of the failure as mapped in the field after the event. Considerations on the volume of the instability and on the development of the failure process (both in space and time) were consequently derived. The results provided a clear example of the value of jointly using ground-based and satellite interferometry to reduce the uncertainties inherent to the identification and characterization of impending catastrophic slope failures. [ABSTRACT FROM AUTHOR]

Earthquake-induced soil liquefaction can cause enormous life and economic losses. The joint distribution of the peak ground surface acceleration ( a max ) and the moment magnitude of an earthquake ( M w ) is crucial to the estimation of soil liquefaction-related hazards. In this paper, a new method is suggested to estimate the joint distribution of a max and M w . Compared with the existing method, the suggested method is easier to implement, and depends on fewer assumptions. The derived joint distribution is then used to assess the damage state of a building caused by soil liquefaction during a given exposure time. The method is illustrated with an example in which a reinforced concrete frame building is assumed to be at different locations and is subjected to different exposure time. It is found that, as the exposure time increases, the chance of higher degree of damage also increases. When the exposure time is the same, the damage state of the building may also be different when it is at different locations. The method suggested in this paper can be used to quantify the effect of ground condition as well as the seismic effects at a site on the damage state of a building, thus providing a more transparent understanding of the risk associated with the soil liquefaction hazard on structural damage. [ABSTRACT FROM AUTHOR]

In recent years, many have mapped the liquefaction potential index (LPI) to describe the liquefaction hazard at regional scale. Several investigators have calibrated the LPI to field observations of liquefaction-induced ground failure after a number of major earthquakes; the significance of LPI values and their correlation with the severity of liquefaction-induced ground failure can vary greatly depending on the calibration. In this study, the LPI was computed at more than 1200 cone penetration test soundings across the Christchurch area, New Zealand, using peak ground accelerations from the 2011 Christchurch Earthquake. Based on detailed field observations of liquefaction-induced ground failure after the earthquake, it was shown that the LPI has potential for discriminating between areas with no liquefaction-induced ground failure hazard and areas that may experience liquefaction-induced ground oscillations and settlement; however, the LPI performed poorly at sites where severe ground failures occurred, especially at sites that experienced lateral spreading. As many researchers have found a positive correlation between lateral spreading and the proximity and depth of a nearby free-face (i.e., a steep topographic depression, river channel, etc.), a new LPI framework was proposed that includes a parameter named the free-face ratio ( FFR ). FFR was shown to have a significant correlation with field observations of lateral spreading in Christchurch. It was shown that by incorporating FFR into the LPI framework, modified LPI values are positively correlated with the severity of field observations of liquefaction-induced ground failure in Christchurch. It was also shown that maps can be produced based on LPI and FFR , and such maps rarely underpredict the liquefaction-induced ground failure hazard, unlike maps based on the unmodified LPI. [ABSTRACT FROM AUTHOR]

The primary aim of this research is to analyze the hazards and seismic performance of reservoirs and typical large dams based on a field investigation following the Wenchuan 8.0 earthquake. The current seismic performance standards being achieved are discussed and further suggestions are given for super high dams. Based on field investigations, statistics are also given on damaged small reservoirs and damage severities, due to the many various types of earthquake threat. It is of interest to note that the major structures of the medium-sized hydropower stations on the Minjiang river did withstand the Wenchuan earthquake, despite earthquake intensity exceeding engineering design expectations. All the dams remained overall stable. The Shapai roller-compacted concrete (RCC) arch dam and the Zipingpu concrete-faced rockfill (CFR) dam suffered damage. The main earthquake-induced hazards to the dam structures and to both abutments are detailed. Case study analyses of the hazards and reinforcement provision revealed that: 1) The Wenchuan earthquake proved very dangerous for small reservoirs, with destroyed reservoirs widely distributed. The risk of failure of small dams can be classified into three levels based on field investigation. 2) The damage to and behavior of the large dams in the area affected by the earthquake prove that the Chinese codes relating to the seismic design of large dams are appropriate. 3) Appropriate reinforcement can increase the overall stiffness of abutments, riverbed foundation and the adjacent slopes, further improving the seismic performance of dams. 4) The design and management of emergency responses, to cope with extreme conditions, should be improved, and a unified response platform, covering all hydropower engineering projects in each valley should be established. The effects to be expected and the seismic design measures to be taken still pose great challenges for engineers in respect of large dams. [ABSTRACT FROM AUTHOR]

Abstract: Peak ground acceleration (PGA) has still been considered one of the important factors that plays significant role on the earthquake-induced damage of structures. Thus, prediction of the PGA and selection of appropriate ground motion models often have become a valuable topic for seismic hazard assessments. This paper presents an application in order to predict the PGA by a relatively new prediction tool, genetic expression programming (GEP) and the conventional method of regression, and then aims to select the appropriate ground motion models derived by the GEP and regression methods. The selection was carried out by comparing the prediction performances through a ranking process using a new goodness-of-fit measure, likelihood estimation (LH), recently proposed by Scherbaum et al. (2004, on the use of response spectral reference data for the selection and ranking of ground-motion models for seismic hazard analysis in regions of moderate seismicity: the case of rock motion. Bulletin of the Seismological Society of America 94, 1–22). The Turkish earthquake data properly organized were used for deriving the candidate ground motion models of PGA attenuation equations. The validations of the LH method as well as the GEP and regression models were performed by the key attenuation characteristics, the attenuation equations for Turkey and the case records of Turkish strong ground motion data. The results indicate that majority of the PGA candidate models (GEP and regressions) that are ranked as good qualifications (class A and B) by the LH method generally pass the model validations, but the ones ranked as lower levels (class C) fail. This finding indicates that the LH method can be beneficial for the comparisons of the candidate ground motion models, and the selection of appropriate models for attenuation studies. Even though the GEP-based models that were found to be appropriate by the LH method need some improvements to obtain simple functional forms of PGA predictive relationships, their PGA predictions were reasonably consistent with the model validations. Thus, this study suggests that the GEP approach can be employed for predicting the PGAs in seismic hazard studies at least as a supplement to conventionally derived predictive relationships from the regressions. [Copyright &y& Elsevier]

A New Paradigm is needed for Reliable Seismic Hazard Assessment RSHA, not only from consideration of (a) the huge human losses experienced in the many recently destructive earthquakes worldwide; but also from (b) theoretical considerations of seismic wave generation and propagation phenomena through often non-homogeneous media within the earth's crust, particularly when large and more complex fault ruptures occur. The Neo-Deterministic Seismic Hazard Assessment (NDSHA) method, proposed some twenty years ago, is found to reliably and realistically simulate the wide suite of earthquake ground motions that may impact civil populations as well as their heritage buildings. The scenario-based NDSHA modeling technique is developed from comprehensive physical knowledge of: (i) the seismic source process; (ii) the propagation of earthquake waves; and (iii) their combined interactions with site effects. Thus, NDSHA effectively accounts for the tensor nature of earthquake ground motions: (a) formally described as the tensor product of the earthquake source functions and the Green's functions of the transmitting (pathway) medium; and (b) more informally described as mathematical arrays of numbers or functions (indices) "that transform according to certain rules under a change of coordinates." Importantly, NDSHA therefore uses all available information about the spacial distribution of large magnitude earthquake phenomena, including: (a) Maximum Credible Earthquake (MCE) – which is based on seismic history and seismotectonics; and (b) geological and geophysical data. Thus it does not rely on scalar empirical ground motion attenuation models (GMPEs), as these are often both: (a) weakly constrained by available observations; and (b) fundamentally unable to account for the tensor nature of earthquake ground motions. • "You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete." — Buckminster Fuller. • The Neo-Deterministic Seismic Hazard Assessment (NDSHA) method, proposed some twenty years ago, is found to reliably and realistically simulate the wide suite of earthquake ground motions that may impact civil populations as well as their heritage buildings. • The scenario-based NDSHA modeling technique is developed from comprehensive physical knowledge of: (i) the seismic source process; (ii) the propagation of earthquake waves; and (iii) their combined interactions with site conditions. • Thus, NDSHA effectively accounts for the tensor nature of earthquake ground motions. • Observations from recent destructive earthquakes in Italy: (i) Mw 5.9 Emilia 2012; (ii) Central Italy Mw 6.3 L'Aquila 2009; and 2016–2017 Seismic Crisis - Mw 6.1 Amatrice; Mw 5.9 Visso; Mw 6.5 Norcia; Mw 5.7 L'Aquila; and (iii) Mw 7.8 Nepal 2015 - have all confirmed the validity of NDSHA's approach and application. • Although damaging earthquakes cannot yet be predicted with ultimate precision , intermediate-term (several months) and middle-range (few 100 s km scale) predictions of main shocks above a pre-assigned threshold (based on seismicity "alarms" generated by interpretive algorithms like CN and M8) may be properly used for the implementation of low-key preventive safety actions. [ABSTRACT FROM AUTHOR]

Southern Peru and northern Chile (17–30°S, 67–74°W) make up a seismically active region due to the convergence of the Nazca Plate and the South American Plate. The region has experienced a number of destructive earthquakes and tsunamis over the past few centuries, which have caused loss of human life and significant damage to infrastructure, highlighting the importance of seismic hazard assessment in the region. In fact, a reliable seismic hazard assessment is critical for developing policies for seismic hazard mitigation and risk reduction. In this study, we performed a probabilistic seismic hazard assessment (PSHA) of the study area based on an earthquake catalog that was very carefully analyzed. In earlier studies, we demonstrated that inappropriate treatment of the earthquake catalog can result in a serious bias in evaluations of seismicity parameters (e.g., a bias of up to 42% in the "b" parameter of the Gutenberg–Richter law). To address this issue, we compiled a homogenous earthquake catalog consisting of 39,977 events during the 1513–2016 period and accounted for site-specific local effects by developing site-specific scaling relationships between different measures of magnitude (e.g., m b , M s , M D) and moment magnitude (M w). The study area was subdivided into 15 seismogenic zones, accounting for site-specific seismicity patterns. The parameters "a" and "b" of the Gutenberg–Richter law were estimated for each zone based on independent earthquake events. The PSHA was performed using a standard logic tree approach, which allowed us to systematically take into account the model-based uncertainty and its influence on the estimated ground motion parameters. Uniform hazard spectra for return periods of 475 and 2475 years were estimated for peak ground accelerations and spectral accelerations at 0.2 s and 1.0 s to meet the definitions of seismic hazards provided by the International Building Code (IBC, International Code Council [ICC], 2009). This study is expected to provide a basis for design maps for building codes and emergency planning. • Probabilistic seismic hazard assessment of the southern Peru and northern Chile region • An unified earthquake catalog using historical and instrumental data • Validation of Ground Motion Prediction Equations for forecasting the ground motion [ABSTRACT FROM AUTHOR]

This study presents a first attempt to couple two of the most important components of seismic risk mitigation strategies: probabilistic seismic hazard analysis (PSHA) and seismic microzonation. We show an application in the westernmost sector of the Liguria region in northwestern Italy, an area where strong earthquakes (up to about magnitude 6.5) occurred in the past producing hundreds of casualties. The final goal is to produce probabilistic seismic hazard maps for peak ground acceleration and spectral acceleration that incorporate site amplification (by amending existing ground motion attenuation models for rock conditions with an additional amplification term provided by microzonation studies) on a municipal scale. To this end, a partially non-ergodic approach is applied according to modern practice. Compared to conventional, ergodic hazard assessments for rock conditions and flat topography, such maps provide at a glance a finer picture of the actual hazard of the area under study, highlighting those sites where the ground motion hazard is dominated by local amplification effects. At these sites, the expected ground motions are up to twice the values resulting from the traditional, ergodic PSHA on rock. Besides hazard maps, results are also presented in terms of uniform hazard spectra for a number of target sites. Comparison with the isoseismal maps of past earthquakes have revealed a good agreement between the spatial distribution of the assessed hazard and that of felt intensities, with greater damage observed in areas presenting significant amplification effects and, consequently, a higher seismic hazard. • We analyze the role of local geology on seismic hazard. • Site effects from seismic microzonation maps are incorporated into PSHA in a robust, fully probabilistic way. • Partially non ergodic, site-specific probabilistic seismic hazard maps are defined. • Site-specific hazard is up to twice the traditional, ergodic hazard on rock. • The hazard distribution agrees well with the damage distribution associated with past earthquakes. [ABSTRACT FROM AUTHOR]