October 23, 2011 Turkey/Van–Ercis earthquake: structural damages in the residential buildings

On October 23, 2011, a magnitude of Mw 7.2 earthquake struck the Van province in eastern Turkey which caused approximately 600 life loss and 4,000 injured people. Although the recorded peak ground accelerations were relatively low (0.15–0.2 g) compared with that of other recent destructive Turkish earthquakes and the code-based design response spectrum, a large number of reinforced concrete buildings with 4–6 stories and non-engineered masonry buildings were either heavily damaged or collapsed in the region. Based on the post-earthquake technical inspections, the goal of this paper is to introduce major reasons for structural damages in the disaster area and to discuss these failures along with the approaches given in the design code which is renewed after August 17, 1999 Marmara Earthquake. Some remarkable lessons learned from earthquake-induced failures and damages specific to building construction techniques are presented in this paper.     

Solution of Kepler’s equation for rectilinear motion

The properties of the solution of the kinematic equation (Kepler’s equation) presented as a series in powers of a function of time are considered for the case of unperturbed, rectilinear elliptical and rectilinear hyperbolic motion. Kepler’s equation for unperturbed, rectilinear elliptical motion has the form E − sinE = z ³/6, where E is the eccentric anomaly determining the position in the orbit, z ³/6 is the mean anomaly, which is proportional to the time measured from an encounter, and its solution can be represented as a series in powers of z. It is established that the coefficients of the series are positive. The asymptotic for the coefficients in the region of convergence of the series is found, which covers the entire orbit. The series continues to converge over the entire boundary of the circle of convergence. The kinematic equation for unperturbed, rectilinear hyperbolic motion has the form sinhH − H = ζ ³/6, where, as before, ζ ³ is proportional to time. The substitution E = iH, z = iζ reduces one equation to the other. The series for the solution in the hyperbolic case differs from the series for the elliptical solution only in its alternating-sign coefficients. However, the region of convergence covers only part of the orbit in the hyperbolic case.     

Field reconnaissance on seismic performance of RC buildings after the January 24, 2020 Elazığ-Sivrice earthquake

Natural Hazards - A moderate earthquake with a magnitude Mw of 6.8 occurred in the Sivrice district of Elaz?? Province in Eastern Turkey on January 24th, 2020. The mainshock and long-term...     

Are earthquake magnitudes exponentially or normally distributed?

Earthquake magnitudes are generally considered to be exponentially distributed. In the present article we argue that a normal distribution can apply as well.     

Should political ecology be Marxist? A case for Gramsci’s historical materialism

This paper investigates some aspects of political ecology’s relation to Marxism, specifically its ties to Marxism’s “historical materialism”. I argue Gramsci is an essential feature in the reinvigoration of that relation, and that political ecology should be Marxist, if by Marxist we mean Gramscian. I focus on the concept of hegemony, arguing that Gramsci’s historical materialism, in contrast to the Engelsian tradition within which most materialism is snared, allows us to take account of both moments in Gramsci’s hegemony, the “economic” and the “ethicopolitical”.     

Can we use tracer tests to obtain data for performance assessment of repositories for nuclear waste?

With regard to the long-term safety of repositories for spent nuclear fuel, tracer tests have commonly been used in site characterisation (SC) for finding information that can be later used for performance assessment (PA). The question arises as to whether data obtained in tracer tests performed over a time scale of weeks or months are relevant for PA calculations. As part of a study overseen by the Äspö Task Force, the mechanisms that determine the radionuclide residence time under SC and PA conditions are addressed, given that they influence the validity of data transference from SC to PA. The results show that radionuclide transport in SC and PA, although governed by the same retardation mechanisms, are dominated by different sub-processes. In a practical sense this means that the parameter values (typically fracture apertures and “in situ” apparent retention data) determined in tracer tests, performed as a part of the SC program, should not be used directly for making PA predictions. The emphasis in SC should focus more on the determination of other parameters of relevance at PA timescales. The PA-specific flow rate, flow connectivity, and flow-wetted surface to flow ratio are given here as examples.     

Expert and information systems for technical SAR measures and buildings’ state evaluation

The situation after earthquake disasters is for a large part of the deployed field units very exceptional. Expert and information systems offer the possibility to support the decisions of the field personnel in such complex and unfamiliar situations. They can be used for training purposes and to support the operations in real cases. Two different expert and information systems were created. The first system supports the onsite search and rescue (SAR) personnel at building collapses and the second supports inspectors evaluating the buildings' states after earthquakes. In both cases, after the input of information related to a certain situation, the expert system poses context-sensitive subsequent questions and gives assistance for the site inspection. The expert and information system for rescue operations then generates advice concerning suitable SAR procedures and equipment for the given situation. Additionally, basic information, checklists and calculation components are offered as support. The expert and information system for the buildings’ state evaluation will assist the inspectors to decide reliably and in short time whether the buildings are safe to be further used or not after an earthquake. Interactive checklists depending on the building type as well as further auxiliary material will support the inspectors in classifying the buildings. Both systems are part of the also developed Disaster Management Tool (DMT). The presentation will include an overview of the knowledge collection and evaluation process, the development stage of both expert and information systems, their integration into the DMT and their use when coping with an earthquake disaster.     

Network design for groundwater monitoring – a case study

 The applicability and usefulness of Geostatistics (kriging) as a tool for optimum selection of sites for monitoring groundwater levels has been demonstrated through a case study. The criterion used is the estimation of error variance. Groundwater level data (pre-monsoon 1994) obtained from 32 observation wells of Upper Kongal basin, Nalgonda District, A.P. (India) has been stochastically analyzed. The spatial distribution of water levels and its associated error variance is computed and the locations having maximum error variance are selected as additional sites for augmenting the existing observational well network. Received: 15 june 1998 · Accepted: 14 December 1998     

Some improved methods for modeling the Earth’s polar motion

Some improved methods for modeling the motions of the Earth’s pole determined by gravitational-tidal, fluctuating-dissipative perturbations occurring on various time scales are presented. The main attention is paid to dynamical linear-regression models and dynamical filtering models, which take into account dynamical measurement errors. Computer simulations of the oscillatory motion of the Earth’s pole for 1995–2010 are also presented.     

The smoke is rising but where is the fire? Exploring effective online map design for wildfire warnings

The current study sought to offer guidance for developing effective web-based mapping tools for wildfire warnings by identifying (1) the important content for facilitating individuals’ decision-making, and (2) the optimal interface design for ensuring usability and ease of information access. A map-based warning tool was prototyped in the Australian context, followed by a usability and effectiveness evaluation through individual interviews and verbal protocol analysis to assess participants’ interaction with the mapping interface and information in response to the simulated warning scenario. The results demonstrated variations in participants’ approaches to wildfire warning response, revealing varied information needs. Specifically, most participants relied on their own assessment of the prospective threat, requiring specific wildfire-related information before eliciting a response. In contrast, the decision of a minority of the participants was motivated by response guidance from agencies, and accurate wildfire information was less important for their response. Imperative information for both types of residents therefore needs to be highlighted in a map-based warning tool to cater to a wide audience. Furthermore, a number of heuristics were identified for designing effective interactive functions to facilitate the control of, and access to, the various maps and textual information presented on the map-based warning interface.     

A unified earthquake catalogue for South Asia covering the period 1900–2014

Seismicity analysis is very much pertinent for Indian subcontinent and its adjoining region which is seismically active including many great earthquakes associated with collision and subduction tectonics in the northern, north-eastern part of the subcontinent and in the Andaman and Nicobar Island. An earthquake catalogue has been generated for South Asia covering the period 1900–2014 by compiling the records of earthquake occurrences from International Seismological Center, Global Centroid Moment Tensor (GCMT), US Geological Survey, India Meteorological Department and published literature. The uniform magnitude scaling in moment magnitude M _W,GCMT is achieved through connecting relationships between different magnitude types. These relationships are derived by orthogonal standard regression analysis on available data pairs. The derived relationships have been compared with the existing equations already reported by others. The catalogue is subsequently subjected to a seismicity declustering algorithm to identify the foreshocks, main-shocks and aftershocks. The catalogue thus compiled is envisaged to be a useful resource for seismotectonic and seismic hazard studies in the region.

     

Deterministic strong ground motion study for the Sitamarhi area near Bihar–Nepal region

We explore the challenges of avalanche and debris flow hazard assessment for urban areas exposed in the Sakhalin region. Avalanches are a threat to more than 60 settlements in the region and debris flows to more than 30. Data are provided for avalanche and debris flow events that occurred in the Sakhalin region between 1928 and 2015. In this paper, the method for the design of hazard maps for snow avalanches and debris flows is described, providing the starting point for any planning constraints in general settlement planning schemes. These maps further allow conducting an assessment of avalanche and debris flow risk within a short time period for a larger territory and at minimum cost.     

Geochemical background – can we calculate it?

 The term "background" is discussed and a definition is suggested to put an end to the currently unsatisfying (non-)definition of geochemical or natural background. Based on the requirements stated in the definition, several simple and robust statistical methods are applied to different data sets (n>50) from the atmosphere, pedosphere, and biosphere in order to explore their potential for the evaluation of a useful and robust background. Compared with the original data set both the calculated distribution, based upon the lower 50% of the values, as well as a 2σ-approximation of the normalised data set lead to promising and realistic results. Both methods seem appropriate for a fast and reliable evaluation of likely upper limits of background values. Nevertheless, even this robust method is not able to present absolute and doubtlessly correct background values. True quantification of any natural or geochemical background still requires a thorough investigation and is impossible without costly expert knowledge. Received: 12 July 1999 · Accepted: 9 September 1999     

Estimation of model parameter of Sumatra earthquake using empirical Green’s function technique and generation of hypothetical earthquake scenario for Andaman Island, India

Empirical Green??s function (EGF) technique is considered to be most effective technique for simulation of ground motions due to a finite earthquake source. In the present paper, this technique has been used to simulate ground motion due to a great earthquake. The coastal region of Sumatra Island has been visited by a great earthquake on December 26, 2004. This earthquake has been recorded at several broadband stations including a nearest broadband station PSI in Indonesia. The shear wave contributions in both horizontal components have been simulated at PSI station using EGF technique. The comparison of simulated and observed waveform has been made for various possibilities of rupture parameters in terms of root mean square error. The final rupture model supports rupture velocity of 3.0?km/s with nucleation point supporting northward propagating rupture that coincide with high-slip asperity defined by Sorensen et al. (Bull Seism Soc Am 97:S139?CS151, 2007). The final modeling parameters have been used to simulate record at MDRS station in coastal state of Tamilnadu, India. In an attempt to model a scenario of great earthquake in the Andaman Island, a hypothetical rupture plane is modeled in this region. The event occurred on August 10, 2008 of magnitude 6.2 (M _w ) recorded on strong motion array at Port Blair has been used as EGF to simulate records due to the hypothetical great earthquake. Possibilities of earthquake due to the oblique strike-slip and thrust mechanism have been modeled in the present paper. Several possibilities of nucleation point for both cases has been considered, and it is seen that variation of peak ground acceleration at Port Blair station for strike-slip and thrust mechanism is 126?C738 gals and 647?C2,571 gals, respectively, which indicate high seismic hazard potential of Andaman Island.     

Could the Twin Towers collapse teach the interaction of dilute pyroclastic density currents with buildings?

Particle-laden turbulent flows, called dilute pyroclastic density currents, can be generated during explosive volcanic eruptions. They are the most hazardous events of interaction with buildings and human environments in volcanic areas. A qualitative comparison with the dusty turbulent shear currents generated after the Twin Towers collapse on September 11, 2001 shows that turbulent, multiphase flow-building interaction causes flow separation and recirculation around the buildings. This simple idea could be applied to dilute pyroclastic density currents, and improved in future by adhoc numerical simulations of flow-building interaction.