Earthquakes occurrences estimation through a parametric semi-Markov approach

The estimation of earthquakes’ occurrences prediction in seismic areas is a challenging problem in seismology and earthquake engineering. Indeed, the prevention and the quantification of possible damage provoked by destructive earthquakes are directly linked to this kind of prevision. In our paper, we adopt a parametric semi-Markov approach. This model assumes that a sequence of earthquakes is seen as a Markov process and besides it permits to take into consideration the more realistic assumption of events’ dependence in space and time. The elapsed time between two consecutive events is modeled as a general Weibull distribution. We determine then the transition probabilities and the so-called crossing states probabilities. We conclude then with a Monte Carlo simulation and the model is validated through a large database containing real data.     

Resilience? Contested meanings and experiences in post-disaster Christchurch,New Zealand

The purpose of this paper is to improve understanding of the relationship between sense of place and community resilience, two concepts described and defined differently reflecting different disciplinary research, policies and practices. We draw on international literature that has focused on the interrelationship between these concepts in the context of natural disasters, as well as the findings of a multidisciplinary project in the post-earthquake Christchurch recovery context. We describe how we developed indicators of resilience linked to sense of place as it relates to home, neighbourhood and the city, including place-based social interaction and the role of scientific and technical information. Through integrating literature with the findings from project interviews and a survey, we offer new ways of considering ‘resilience’ and we discuss the implications of our findings for not just the Christchurch recovery, but for future response and recovery to natural disasters throughout New Zealand.     

Rolling with the shakes: an insight into teenagers’ perceptions of recovery after the Canterbury earthquakes

Natural disasters are harmful worldwide events that inflict multiple psychosocial impacts on disaster-exposed individuals. A significant proportion of affected individuals are teenagers (13–18 years old) who, compared with adults, have been historically overlooked in disaster research. The literature is particularly sparse concerning teenagers’ recovery from natural disasters, specifically what recovery means to them and the contributing factors towards their positive recovery. Therefore, the aim of the current study was to gain deeper insight into this largely unexplored area by conducting five focus groups with teenagers (16–18 years) who experienced at least one of the Canterbury, New Zealand, earthquakes since and including the initial September 2010 earthquake. This study directly asked teenagers about their recovery over the three years after the initial earthquakes, with data being analysed using thematic analysis. Two main themes were identified: (1) perceptions of recovery, with three sub-themes (i) knowledge and being less frightened, (ii) talking about the earthquakes and (iii) shift in perspectives; and (2) contributing factors to recovery, with three sub-themes (i) participation in the community response, (ii) returning to school and (iii) the rebuild of Christchurch. These factors provide insight into how we can better support the recovery process for disaster-exposed teenagers to reduce long-term distress.     

Hazardous Materials Releases in the Northridge Earthquake: Implications for Seismic Risk Assessment

In recent years, increasing attention has been given to the problem of earthquake-initiated hazardous materials releases (EIHRs). While the evidence indicates that EHIRs are an important part of the earthquake hazard profile, little attention has been given to documenting them in a way that could form the basis for more systematic estimates of their probability and consequences. Data from the January 17, 1994 Northridge earthquake document the range and nature of hazardous materials events in the impact area, including those at fixed-site facilities and in transportation systems. Proportional estimates of hazmat incidence are provided, and the implications of these data for developing risk assessments and earthquake hazard management are discussed.     

Earthquake Culture and Corporate Action

In this paper we examine the effects of different components of corporate culture on two different categories of action in both routine and jolted environments. Data were collected on a heterogeneous sample of 54 corporations in the San Francisco Bay Area. We examined how the values, knowledge, and practices dimensions of corporate culture influenced actions to prepare for responding to future earthquake disasters and actions to mitigate or reduce future physical and associated earthquake losses. The findings show that corporate earthquake culture is a multidimensional concept, that varied elements of culture function to impact corporate action differently is distinct organizational environments, and that culture's impact on organizational action is contingent on the type of action being considered.     

Finding and fixing systems weaknesses: probabilistic methods and applications of engineering risk analysis.

Methods of engineering risk analysis are based on a functional analysis of systems and on the probabilities (generally Bayesian) of the events and random variables that affect their performances. These methods allow identification of a system's failure modes, computation of its probability of failure or performance deterioration per time unit or operation, and of the contribution of each component to the probabilities and consequences of failures. The model has been extended to include the human decisions and actions that affect components' performances, and the management factors that affect behaviors and can thus be root causes of system failures. By computing the risk with and without proposed measures, one can then set priorities among different risk management options under resource constraints. In this article, I present briefly the engineering risk analysis method, then several illustrations of risk computations that can be used to identify a system's weaknesses and the most cost-effective way to fix them. The first example concerns the heat shield of the space shuttle orbiter and shows the relative risk contribution of the tiles in different areas of the orbiter's surface. The second application is to patient risk in anesthesia and demonstrates how the engineering risk analysis method can be used in the medical domain to rank the benefits of risk mitigation measures, in that case, mostly organizational. The third application is a model of seismic risk analysis and mitigation, with application to the San Francisco Bay area for the assessment of the costs and benefits of different seismic provisions of building codes. In all three cases, some aspects of the results were not intuitively obvious. The probabilistic risk analysis (PRA) method allowed identifying system weaknesses and the most cost-effective way to fix them.     

唐代京师地震及唐人地震观

唐代地震具有时段上的典型性,同时,京师地区具有典型的区域研究价值。为探讨唐代京师地震的特征,分析唐人在同地震接触过程中逐步形成和树立的地震观,运用文献分析法进行分析。研究认为,唐代290年间,京师地区共发生地震34年次,唐代京师地震具有明显的时段性,连续性地震偏多,且地震的破坏力较大;唐人的地震观主要表现为地震的天人感应观,这是主流观念,其固定的认知模式是系列的因果关系:君主“人政乖错”-阴阳五行失调-“天地见眚”上天示警-发生地震-君主修政“体励虔恭”-“变异自消,休征可致”;柳宗元对地震成因的解释表现为地震的自然成因观,但并不盛行。唐代京师地震具有典型的研究价值,唐人可能已经不太认可天象与地震的关联,并重新构建了天象与地震的关系:与地震有密切关系的是某些具体星辰运动和亮度的变化,其他星象变化不能够引起地震;相较于汉代,这是认识上的进步。     

Sojourning With the Homogeneous Poisson Process

In this pedagogical article, distributional properties, some surprising, pertaining to the homogeneous Poisson process (HPP), when observed over a possibly random window, are presented. Properties of the gap-time that covered the termination time and the correlations among gap-times of the observed events are obtained. Inference procedures, such as estimation and model validation, based on event occurrence data over the observation window, are also presented. We envision that through the results in this article, a better appreciation of the subtleties involved in the modeling and analysis of recurrent events data will ensue, since the HPP is arguably one of the simplest among recurrent event models. In addition, the use of the theorem of total probability, Bayes’ theorem, the iterated rules of expectation, variance and covariance, and the renewal equation could be illustrative when teaching distribution theory, mathematical statistics, and stochastic processes at both the undergraduate and graduate levels. This article is targeted toward both instructors and students.     

Second‐order analysis of marked inhomogeneous spatiotemporal point processes: Applications to earthquake data

To analyze interactions in marked spatiotemporal point processes (MSTPPs), we introduce marked second‐order reduced moment measures and K‐functions for inhomogeneous second‐order intensity‐reweighted stationary MSTPPs. These summary statistics, which allow us to quantify dependence between different mark‐based classifications of points, depend on the specific mark space and mark reference measure chosen. Unbiased and consistent minus‐sampling estimators are derived for all statistics considered, and a test for random labeling is indicated. In addition, we treat Voronoi intensity estimators for MSTPPs. These new statistics are finally employed to analyze an Andaman Sea earthquake data set.