http://www.nat-hazards-earth-syst-sci.net/Natural Hazards and Earth System Science Latest Articlesenhttp://www.nat-hazards-earth-syst-sci.net/12/267/2012/<b>Corrigendum to "Impact of rainfall spatial distribution on rainfall-runoff modelling efficiency and initial soil moisture conditions estimation" published in Nat. Hazards Earth Syst. Sci., 11, 157–170, 2011</b><br /><br />Natural Hazards and Earth System Science, 12, 267-267, 2012<br /><br />Author(s): Y. Tramblay, C. Bouvier, P.-A. Ayral, and A. Marchandise<br /><br />No abstract available.Fri, 03 Feb 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/255/2012/<b>Relationship between the spatial distribution of SMS messages reporting needs and building damage in 2010 Haiti disaster</b><br /><br />Natural Hazards and Earth System Science, 12, 255-265, 2012<br /><br />Author(s): C. Corbane, G. Lemoine, and M. Kauffmann<br /><br />Just 4 days after the <i>M</i> = 7.1 earthquake on 12 January 2010, Haitians could send SMS messages about their location and urgent needs through the on-line mapping platform Ushahidi. This real-time crowdsourcing of crisis information provided direct support to key humanitarian resources on the ground, including Search and Rescue teams. In addition to its use as a knowledge base for rescue operations and aid provision, the spatial distribution of geolocated SMS messages may represent an early indicator on the spatial distribution and on the intensity of building damage. <br><br> This work explores the relationship between the spatial patterns of SMS messages and building damage. The latter is derived from the detailed damage assessment of individual buildings interpreted in post-earthquake airborne photos. The interaction between SMS messages and building damage is studied by analyzing the spatial structure of the corresponding bivariate patterns. <br><br> The analysis is performed through the implementation of cross Ripley's K-function which is suitable for characterizing the spatial structure of a bivariate pattern, and more precisely the spatial relationship between two types of point sets located in the same study area. <br><br> The results show a strong attraction between the patterns exhibited by SMS messages and building damages. The interactions identified between the two patterns suggest that the geolocated SMS can be used as early indicators of the spatial distribution of building damage pattern. Accordingly, a statistical model has been developed to map the distribution of building damage from the geolocated SMS pattern. <br><br> The study presented in this paper is the first attempt to derive quantitative estimates on the spatial patterns of novel crowdsourced information and correlate these to established methods in damage assessment using remote sensing data. The consequences of the study findings for rapid damage detection in post-emergency contexts are discussed.Thu, 02 Feb 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/241/2012/<b>On the influence of topographic, geological and cryospheric factors on rock avalanches and rockfalls in high-mountain areas</b><br /><br />Natural Hazards and Earth System Science, 12, 241-254, 2012<br /><br />Author(s): L. Fischer, R. S. Purves, C. Huggel, J. Noetzli, and W. Haeberli<br /><br />The ongoing debate about the effects of changes in the high-mountain cryosphere on rockfalls and rock avalanches suggests a need for more knowledge about characteristics and distribution of recent rock-slope instabilities. This paper investigates 56 sites with slope failures between 1900 and 2007 in the central European Alps with respect to their geological and topographical settings and zones of possible permafrost degradation and glacial recession. Analyses of the temporal distribution show an increase in frequency within the last decades. A large proportion of the slope failures (60%) originated from a relatively small area above 3000 m a.s.l. (i.e. 10% of the entire investigation area). This increased proportion of detachment zones above 3000 m a.s.l. is postulated to be a result of a combination of factors, namely a larger proportion of high slope angles, high periglacial weathering due to recent glacier retreat (almost half of the slope failures having occurred in areas with recent deglaciation), and widespread permafrost occurrence. The lithological setting appears to influence volume rather than frequency of a slope failure. However, our analyses show that not only the changes in cryosphere, but also other factors which remain constant over long periods play an important role in slope failures.Tue, 31 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/231/2012/<b>PM-GCD – a combined IR–MW satellite technique for frequent retrieval of heavy precipitation</b><br /><br />Natural Hazards and Earth System Science, 12, 231-240, 2012<br /><br />Author(s): D. Casella, S. Dietrich, F. Di Paola, M. Formenton, A. Mugnai, F. Porcù, and P. Sanò<br /><br />Precipitation retrievals based on measurements from microwave (MW) radiometers onboard low-Earth-orbit (LEO) satellites can reach high level of accuracy – especially regarding convective precipitation. At the present stage though, these observations cannot provide satisfactory coverage of the evolution of intense and rapid precipitating systems. As a result, the obtained precipitation retrievals are often of limited use for many important applications – especially in supporting authorities for flood alerts and weather warnings. To tackle this problem, over the past two decades several techniques have been developed combining accurate MW estimates with frequent infrared (IR) observations from geosynchronous (GEO) satellites, such as the European Meteosat Second Generation (MSG). In this framework, we have developed a new fast and simple precipitation retrieval technique which we call Passive Microwave – Global Convective Diagnostic, (PM-GCD). This method uses MW retrievals in conjunction with the Global Convective Diagnostic (GCD) technique which discriminates deep convective clouds based on the difference between the MSG water vapor (6.2 μm) and thermal-IR (10.8 μm) channels. Specifically, MSG observations and the GCD technique are used to identify deep convective areas. These areas are then calibrated using MW precipitation estimates based on observations from the Advanced Microwave Sounding Unit (AMSU) radiometers onboard operational NOAA and Eumetsat satellites, and then finally propagated in time with a simple tracking algorithm. In this paper, we describe the PM-GCD technique, analyzing its results for a case study that refers to a flood event that struck the island of Sicily in southern Italy on 1–2 October 2009.Tue, 31 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/229/2012/<b>Book Review of "Adaptation to Climate Change: From Resilience to Transformation"</b><br /><br />Natural Hazards and Earth System Science, 12, 229-230, 2012<br /><br />Author(s): R. Djalante<br /><br />Mon, 30 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/217/2012/<b>Reverse flood routing with the inverted Muskingum storage routing scheme</b><br /><br />Natural Hazards and Earth System Science, 12, 217-227, 2012<br /><br />Author(s): A. D. Koussis, K. Mazi, S. Lykoudis, and A. A. Argiriou<br /><br />This work treats reverse flood routing aiming at signal identification: inflows are inferred from observed outflows by orienting the Muskingum scheme against the wave propagation direction. Routing against the wave propagation is an ill-posed, inverse problem (small errors amplify, leading to large spurious responses); therefore, the reverse solution must be smoothness-constrained towards stability and uniqueness (regularised). Theoretical constrains on the coefficients of the reverse routing scheme assist in error control, but optimal grids are derived by numerical experimentation. Exact solutions of the convection-diffusion equation, for a single and a composite wave, are reverse-routed and in both instances the wave is backtracked well for a range of grid parameters. In the arduous test of a square pulse, the result is comparable to those of more complex methods. Seeding outflow data with random errors enhances instability; to cope with the spurious oscillations, the reversed solution is conditioned by smoothing via low-pass filtering or optimisation. Good-quality inflow hydrographs are recovered with either smoothing treatment, yet the computationally demanding optimisation is superior. Finally, the reverse Muskingum routing method is compared to a reverse-solution method of the St. Venant equations of flood wave motion and is found to perform equally well, at a fraction of the computing effort. This study leads us to conclude that the efficiently attained good inflow identification rests on the simplicity of the Muskingum reverse routing scheme that endows it with numerical robustness.Fri, 20 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/201/2012/<b>The 13 August 2010 catastrophic debris flows after the 2008 Wenchuan earthquake, China</b><br /><br />Natural Hazards and Earth System Science, 12, 201-216, 2012<br /><br />Author(s): Q. Xu, S. Zhang, W. L. Li, and Th. W. J. van Asch<br /><br />From 12 to 14 August 2010, heavy rainstorms occurred in the Sichuan province in SW China in areas which were affected by the 2008 Wenchuan Earthquake, inducing catastrophic debris flows. This disaster is named as "the 8.13 debris flows". The results of the research presented in this paper show that the 8.13 debris flows are characterized by a simultaneous occurrence, rapid-onsets, destructive impacts, and disaster chain effects. They are located along the seismic fault, because the source materials mainly originate from loose deposits of landslides which were triggered by the Wenchuan Earthquake. The presence of large amounts of these loose materials on the slopes and the development of high intensity rainfall events are the main causes for the formation of these debris flows. The study of the 8.13 debris flows can provide a benchmark for the analysis of the long-term evolution of these debris flows in order to make proper engineering decisions. A flexible drainage system is proposed in this paper as a preventive measure to mitigate the increasing activity of these debris flows in the earthquake-affected area.Thu, 19 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/187/2012/<b>Physically-based modelling of granular flows with Open Source GIS</b><br /><br />Natural Hazards and Earth System Science, 12, 187-200, 2012<br /><br />Author(s): M. Mergili, K. Schratz, A. Ostermann, and W. Fellin<br /><br />Computer models, in combination with Geographic Information Sciences (GIS), play an important role in up-to-date studies of travel distance, impact area, velocity or energy of granular flows (e.g. snow or rock avalanches, flows of debris or mud). Simple empirical-statistical relationships or mass point models are frequently applied in GIS-based modelling environments. However, they are only appropriate for rough overviews at the regional scale. In detail, granular flows are highly complex processes and physically-based, distributed models are required for detailed studies of travel distance, velocity, and energy of such phenomena. One of the most advanced theories for understanding and modelling granular flows is the Savage-Hutter type model, a system of differential equations based on the conservation of mass and momentum. The equations have been solved for a number of idealized topographies, but only few attempts to find a solution for arbitrary topography or to integrate the model with GIS are known up to now. The work presented is understood as an initiative to integrate a fully physically-based model for the motion of granular flows, based on the extended Savage-Hutter theory, with GRASS, an Open Source GIS software package. The potentials of the model are highlighted, employing the Val Pola Rock Avalanche (Northern Italy, 1987) as the test event, and the limitations as well as the most urging needs for further research are discussed.Tue, 17 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/175/2012/<b>Tsunamigenic Ratio of the Pacific Ocean earthquakes and a proposal for a Tsunami Index</b><br /><br />Natural Hazards and Earth System Science, 12, 175-185, 2012<br /><br />Author(s): A. Suppasri, F. Imamura, and S. Koshimura<br /><br />The Pacific Ocean is the location where two-thirds of tsunamis have occurred, resulting in a great number of casualties. Once information on an earthquake has been issued, it is important to understand if there is a tsunami generation risk in relation with a specific earthquake magnitude or focal depth. This study proposes a Tsunamigenic Ratio (TR) that is defined as the ratio between the number of earthquake-generated tsunamis and the total number of earthquakes. Earthquake and tsunami data used in this study were selected from a database containing tsunamigenic earthquakes from prior 1900 to 2011. The TR is calculated from earthquake events with a magnitude greater than 5.0, a focal depth shallower than 200 km and a sea depth less than 7 km. The results suggest that a great earthquake magnitude and a shallow focal depth have a high potential to generate tsunamis with a large tsunami height. The average TR in the Pacific Ocean is 0.4, whereas the TR for specific regions of the Pacific Ocean varies from 0.3 to 0.7. The TR calculated for each region shows the relationship between three influential parameters: earthquake magnitude, focal depth and sea depth. The three parameters were combined and proposed as a dimensionless parameter called the Tsunami Index (TI). TI can express better relationship with the TR and with maximum tsunami height, while the three parameters mentioned above cannot. The results show that recent submarine earthquakes had a higher potential to generate a tsunami with a larger tsunami height than during the last century. A tsunami is definitely generated if the TI is larger than 7.0. The proposed TR and TI will help ascertain the tsunami generation risk of each earthquake event based on a statistical analysis of the historical data and could be an important decision support tool during the early tsunami warning stage.Tue, 17 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/165/2012/<b>A proposal for a methodological approach to the characterisation of Widespread Landslide Events: an application to Southern Italy</b><br /><br />Natural Hazards and Earth System Science, 12, 165-173, 2012<br /><br />Author(s): G. Gullà, T. Caloiero, R. Coscarelli, and O. Petrucci<br /><br />This paper presents a methodological approach to both identifying and characterising Widespread Landslide Events (WLE), defined as the occurrence of several landslides through wide areas (thousands of square kilometres). This approach is based on a comparative analysis of two historical databases: a rainfall database and a landslide database, both concerning the same period. <br><br> This methodology was tested on Calabria (Southern Italy) by analysing a period of more than 80 yr. The data allowed the individuation of 25 WLEs generated by the following: (a) a single rainfall event (RE), (b) a few distinct but temporarily close REs, or (c) several consecutive REs occurring over a period of up to two months. An empirical curve, obtained by interpolating the number of landslides occurred during the WLEs and the average values of cumulative rainfall that triggered them enables the individuation of the relationship between rainfall and number of landslides. <br><br> The proposed methodological approach can be used wherever historical series of both rainfall and landslides are available. The results can be useful for monitoring the development of events and for the planning of emergency management.Tue, 17 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/151/2012/<b>Tsunami risk assessments in Messina, Sicily – Italy</b><br /><br />Natural Hazards and Earth System Science, 12, 151-163, 2012<br /><br />Author(s): A. Grezio, P. Gasparini, W. Marzocchi, A. Patera, and S. Tinti<br /><br />We present a first detailed tsunami risk assessment for the city of Messina where one of the most destructive tsunami inundations of the last centuries occurred in 1908. In the tsunami hazard evaluation, probabilities are calculated through a new general modular Bayesian tool for Probability Tsunami Hazard Assessment. The estimation of losses of persons and buildings takes into account data collected directly or supplied by: (i) the Italian National Institute of Statistics that provides information on the population, on buildings and on many relevant social aspects; (ii) the Italian National Territory Agency that provides updated economic values of the buildings on the basis of their typology (residential, commercial, industrial) and location (streets); and (iii) the Train and Port Authorities. For human beings, a factor of time exposition is introduced and calculated in terms of hours per day in different places (private and public) and in terms of seasons, considering that some factors like the number of tourists can vary by one order of magnitude from January to August. Since the tsunami risk is a function of the run-up levels along the coast, a variable tsunami risk zone is defined as the area along the Messina coast where tsunami inundations may occur.Tue, 17 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/143/2012/<b>GIS-based coastal area suitability assessment of geo-environmental factors in Laoshan district, Qingdao</b><br /><br />Natural Hazards and Earth System Science, 12, 143-150, 2012<br /><br />Author(s): C. Y. Ju, Y. G. Jia, H. X. Shan, C. W. Tang, and W. J. Ma<br /><br />With increasing urbanization, particularly in the coastal regions of developing countries, the development of disaster management schemes is needed as the losses from a single event can destroy decades of development and threaten local populations, buildings and infrastructure. Geo-environmental suitability is often evaluated systematically in order to assess the nature of hazards and their potential damage to human life, land, buildings and other property. A suitability assessment will indicate the priorities for geological and environmental hazard management. This paper presents a geological environment suitability assessment that aims to identify grading in a current seaside urban development and develop practices to aid in the identification of hidden geological and environmental hazards. The Laoshan area in the city of Qingdao was used as a case study because it constitutes a good example of a developing city with geological and environmental threats. Also, urban plans have been drawn up here with insufficient or absent information on losses from potential natural hazards.Tue, 17 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/129/2012/<b>The occurrence of floods and the role of climate variations from 1880 in Calabria (Southern Italy)</b><br /><br />Natural Hazards and Earth System Science, 12, 129-142, 2012<br /><br />Author(s): M. Polemio and O. Petrucci<br /><br />In this paper, we present a methodological approach based on a comparative analysis of floods that occurred in a wide region over a long period and the climatic data characterising the same period, focusing on the climate trend. The method simplifies the comparative analysis of several time series by defining some indexes (e.g. the monthly, bi-monthly, and ... <i>m</I>-monthly indexes of precipitation, temperature, wet days and precipitation intensity and the monthly flood number) that can be used to study phenomena such as floods that are characterised by spatial and temporal variability. The analysis was used to investigate the potential effect of climate variation on the damaging floods trend. <br><br> The approach was tested for the Calabria region (Italy) using historical flood and climatic data from 1880 to 2007. The results showed that the number of floods was correlated with the monthly indexes of precipitation, wet days, and daily precipitation intensity. The following trends were recognised: decreasing precipitation and wet days, almost constant precipitation intensity, increasing temperature, and linearly increasing floods. A second-order polynomial trend analysis showed a slight decrease in floods since the seventies, which might be explained by the favourable climatic conditions during the period and/or the effect of increasing awareness of flood vulnerability.Fri, 13 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/121/2012/<b>Variations of geoelectric potential differences associated with an anomalous volumetric strain change in the region of expected Tokai Earthquake, Japan</b><br /><br />Natural Hazards and Earth System Science, 12, 121-127, 2012<br /><br />Author(s): Y. Orihara, M. Kamogawa, T. Nagao, and S. Uyeda<br /><br />For the prediction of the expected Tokai Earthquake (EQ), Japan Meteorological Agency (JMA) has been observing volumetric strain changes to detect its presumed pre-slip phenomena in Tokai and South Kanto regions. In 1998, an anomalous volumetric strain change, lasting for 5 days, which initially attracted much attention as a possible precursor to the Tokai EQ, was observed at Shimizu station in the Tokai area. Eventually, the Tokai EQ did not occur and the causal mechanism of the observed anomaly was unknown. However, we found variations of geoelectric potential differences (GPD) possibly associated with the anomaly by applying Principal Component Analysis (PCA) to the GPD data taken in the same area. From the polarities of the observed GPD changes, we infer that these GPD variations were caused by electrokinetic effects of groundwater motion, which might have been related with the strain changes. These results imply that the GPD observations may assist us in understanding the nature of EQ precursory phenomena.Thu, 12 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/107/2012/<b>Identification of elements at risk for a credible tsunami event for Istanbul</b><br /><br />Natural Hazards and Earth System Science, 12, 107-119, 2012<br /><br />Author(s): U. Hancilar<br /><br />Physical and social elements at risk are identified for a credible tsunami event for Istanbul. For this purpose, inundation maps resulting from probabilistic tsunami hazard analysis for a 10% probability of exceedance in 50 yr are utilised in combination with the geo-coded inventories of building stock, lifeline systems and demographic data. The built environment on Istanbul's shorelines that is exposed to tsunami inundation comprises residential, commercial, industrial, public (governmental/municipal, schools, hospitals, sports and religious), infrastructure (car parks, garages, fuel stations, electricity transformer buildings) and military buildings, as well as piers and ports, gas tanks and stations and other urban elements (e.g., recreational facilities). Along the Marmara Sea shore, Tuzla shipyards and important port and petrochemical facilities at Ambarlı are expected to be exposed to tsunami hazard. Significant lifeline systems of the city of Istanbul such as natural gas, electricity, telecommunication and sanitary and waste-water transmission, are also under the threat of tsunamis. In terms of social risk, it is estimated that there are about 32 000 inhabitants exposed to tsunami hazard.Wed, 11 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/97/2012/<b>Efficient dam break flood simulation methods for developing a preliminary evacuation plan after the Wenchuan Earthquake</b><br /><br />Natural Hazards and Earth System Science, 12, 97-106, 2012<br /><br />Author(s): Y. Li, J. H. Gong, J. Zhu, L. Ye, Y. Q. Song, and Y. J. Yue<br /><br />The Xiaojiaqiao barrier lake, which was the second largest barrier lake formed by the Wenchuan Earthquake had seriously threatened the lives and property of the population downstream. The lake was finally dredged successfully on 7 June 2008. Because of the limited time available to conduct an inundation potential analysis and make an evacuation plan, barrier lake information extraction and real-time dam break flood simulation should be carried out quickly, integrating remote sensing and geographic information system (GIS) techniques with hydrologic/hydraulic analysis. In this paper, a technical framework and several key techniques for this real-time preliminary evacuation planning are introduced. An object-oriented method was used to extract hydrological information on the barrier lake from unmanned aerial vehicle (UAV) remote sensing images. The real-time flood routine was calculated by using shallow-water equations, which were solved by means of a finite volume scheme on multiblock structured grids. The results of the hydraulic computations are visualized and analyzed in a 3-D geographic information system for inundation potential analysis, and an emergency response plan is made. The results show that if either a full-break or a half-break situation had occurred for the Chapinghe barrier lake on 19 May 2008, then the Xiaoba Town region and the Sangzao Town region would have been affected, but the downstream towns would have been less influenced. Preliminary evacuation plans under different dam break situations can be effectively made using these methods.Wed, 11 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/85/2012/<b>Reduction of tsunami inundation by coastal forests in Yogyakarta, Indonesia: a numerical study</b><br /><br />Natural Hazards and Earth System Science, 12, 85-95, 2012<br /><br />Author(s): W. Ohira, K. Honda, and K. Harada<br /><br />Coastal forests are known to protect coastal areas from environmental degradation. In this paper, we examined another important role of coastal forests – to mitigate tsunami devastations to coastal areas. Using a two-dimensional numerical model (Harada and Imamura model, 2005), we evaluated the damping effects of a coastal forest to resist tsunami inundation in Yogyakarta, Indonesia. In the simulations, we set up a two-km long control forest with a representative topography of the study site and experimented its damping performance sensitivity under various width configurations, e.g. 20, 40, 60, 80, 100 and 200 m. The initial tsunami wave was set such that the inundation depth at the front edge of the forest would not exceed 4 m (tree fragility limit). The forest variables such as species, density, DBH, height and canopy size were determined from a typical forest of the site (<i>Casuarina</i> plantation, 4 trees/100 m², Diameter at Breast Height = 0.20 m). The results showed that coastal forest with 100 m width reduced inundation flux, depth and area by 17.6, 7.0 and 5.7%, respectively. Exponential models were found to describe the relationships between forest width and tsunami inundation transmission. An additional experiment was performed using actual topography and a forest plantation plan with 100 m width for 2.46 km². In this experiment, the results showed that the plan would reduce inundation flux by 10.1%, while the exponential model estimated it to be 10.6%, close to the numerical model results. It suggests that statistical models of forest width and damping effects are useful tools for plantation planning, as it allows for quicker evaluation of the impact of coastal forest without simulation modeling that requires a lot of data, time and computing power.Wed, 11 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/75/2012/<b>Phenomena of electrostatic perturbations before strong earthquakes (2005–2010) observed on DEMETER</b><br /><br />Natural Hazards and Earth System Science, 12, 75-83, 2012<br /><br />Author(s): X. Zhang, X. Shen, M. Parrot, Z. Zeren, X. Ouyang, J. Liu, J. Qian, S. Zhao, and Y. Miao<br /><br />During the DEMETER operating period in 2004–2010, many strong earthquakes took place in the world. 69 strong earthquakes with a magnitude above 7.0 during January 2005 to February 2010 were collected and analysed. The orbits, recorded in local nighttime by satellite, were chosen by a distance of 2000 km to the epicentres during the 9 days around these earthquakes, with 7 days before and 1 day after. The anomaly is defined when the disturbances in the electric field PSD increased to at least 1 order of magnitude relative to the normal median level about 10^&minus;2μV²/m²/Hz at 19.5–250 Hz frequency band, and the starting point of perturbations not exceeding 10° relsupative to the epicentral latitude. Among the 69 earthquakes, it is shown that electrostatic perturbations were detected at ULF-ultra low frequency and ELF-extremely low frequency band before the 32 earthquakes, nearly 46%. Furthermore, we extended the searching scale of these perturbations to the globe, and it can be found that before some earthquakes, the electrostatic anomalies were distributed in a much larger area a few days before, and then they concentrated to the closest orbit when the earthquake would happen one day or a few hours later, which reflects the spatial developing feature during the seismic preparation process. The results in this paper contribute to a better description of the electromagnetic (EM) disturbances at an altitude of 660–710 km in the ionosphere that can help towards a further understanding of the lithosphere-atmosphere-ionosphere (LAI) coupling mechanism.Mon, 09 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/61/2012/<b>Hardware-software system for simulating and analyzing earthquakes applied to civil structures</b><br /><br />Natural Hazards and Earth System Science, 12, 61-73, 2012<br /><br />Author(s): J. P. Amezquita-Sanchez, R. A. Osornio-Rios, R. J. Romero-Troncoso, and A. Dominguez-Gonzalez<br /><br />The occurrence of recent strong earthquakes, the incessant worldwide movements of tectonic plates and the continuous ambient vibrations caused by traffic and wind have increased the interest of researchers in improving the capacity of energy dissipation to avoid damages to civil structures. Experimental testing of structural systems is essential for the understanding of physical behaviors and the building of appropriate analytic models in order to expose difficulties that may not have been considered in analytical studies. This paper presents a hardware-software system for exciting, monitoring and analyzing simultaneously a structure under earthquake signals and other types of signals in real-time. Effectiveness of the proposed system has been validated by experimental case studies and has been found to be a useful tool in the analysis of earthquake effects on structures.Fri, 06 Jan 2012 00:00:00 +0100http://www.nat-hazards-earth-syst-sci.net/12/53/2012/<b>Solving the dilemma of transforming landslide hazard maps into effective policy and regulations</b><br /><br />Natural Hazards and Earth System Science, 12, 53-60, 2012<br /><br />Author(s): J. V. DeGraff<br /><br />As geoscientists, we often perceive the production of a map or model to adequately define landslide hazard for an area as the answer or end point for reducing risk to people and property. In reality, the risk to people and property remains pretty much the same as it did before the map existed. Real landslide risk reduction takes place when the activities and populations at risk are changed so the consequences of a landslide event results in lower losses. Commonly, this takes place by translating the information embodied in the landslide hazard map into some change in policy and regulation applying to the affected area. This is where the dilemma arises. Scientific information generally has qualifications, gradations, and conditions associated with it. Regulations are necessarily written in language that tries to avoid any need for interpretation. Effectively incorporating geologic information into regulations and ordinances requires continued involvement with their development and implementation. Unless geoscientists are willing to participate in that process, sustainable risk reduction is unlikely to occur.Fri, 06 Jan 2012 00:00:00 +0100