1,720,995 research outputs found
Tsunami modeling of a submarine landslide in the Fram Strait
No full textThe present geological setting west of Svalbard closely parallels the situation off mid-Norway after the last glaciation, when crustal unloading by melting of ice induced very large earthquakes. Today, on the modern Svalbard margin, increasing bottom water temperatures are destabilizing marine gas hydrates, which are held in continental margin sediments consisting of interlayered contourite deposits and glacigenic debris flows. Both unloading earthquakes and hydrate failure have been identified as key factors causing several megalandslides off Norway during early Holocene deglaciation. The most prominent event was the Storegga Slide 8200 years B.P. which caused a tsunami up to 23 m high on the Faroe and Shetland islands. Here we show by numerical tsunami modeling that a smaller submarine landslide west of Svalbard, 100 m high and 130 km wide, would cause a tsunami capable of reaching northwest Europe and threatening coastal areas. A tsunami warning system based on tiltmeters would give a warning time of 1–4 h
New Multi-Hazard and Multi-Risk Assessment Methods for Europe. Risk governance and the communication process from science to policy: Evaluating perceptions of stakeholders from practice in multi-hazard and multi-risk decision support models: MATRIX results II and Reference Report
No full textSatellite-based forest fire detection and automatic alert system:Pilot Experiment
No full textA fully automatic system has been developed to detect forest fires using data from the meteorological NOAA satellites. The system has been tested in four pilot experiments in 1994–1998 in Finland and its neighbouring countries Estonia, Latvia, Russian Carelia, Sweden and Norway. For each detected fire, a telefax including data on the location of the fire, the observation time and a map showing the location, is sent directly to the local fire authorities. The area of the smallest forest fires detected was 0.1 ha. The time delay between receiving the NOAA scene and the sending of the fire alert was 31 min in average. Nearly all detected fires were forest fires or prescribed burnings. In the pilot experiment of the summer 1997 363 fires were observed and alerted. The verification showed that 83% of the given alerts concerned real fires. According to the authorities, none of the real significant forest fires in Finland remained undetected. The good verification results show that satellite-based detection system of forest fires is reliable, fast and cost effective, and it has potential in sparsely populated areas if continuous supply of middle-infrared satellite data can be guaranteed in the future. Because of the ecological and human necessity, fire monitoring and alert system on a global scale should be established urgently. For this purpose dedicated fire detection instruments and satellites should be developed
The Last-Mile Evacuation project: A multi-disciplinary to evacuation planning and risk reduction in tsunami-threatened coastal areas
No full textIn view of recent tragic and disastrous tsunami events such as the Indian Ocean tsunami in 2004 or the Tohoku-Oki tsunami in 2011 it is still indispensable to aim at deepening our insight into the mechanisms which turn natural disasters into life-changing events for those individuals living at regions at risk. In this context risk mitigation on the basis of wellimplemented early warning systems is inevitable to reduce human losses and to pave the way for specific measures on disaster recovery. A possible work
chain to assess this complex objective is exemplified by the interdisciplinary “Last-Mile Evacuation project” which focused on the city of Padang, Indonesia. This city is one of the cities worldwide most imperiled by tsunamis since it is located in the direct neighborhood to the Sunda arc with an average warning time below 30 minutes. The work chain presented in the present paper comprises the generation and compilation of the underlying geo data basis, the simulation of hydrodynamics, the assessment of physical
vulnerability using remote sensing data and techniques, the assessment of social vulnerability related with people´s exposure, risk perception, and evacuation behavior, and the modeling of potential evacuation routes. While the main focus of the original project was on city-wide risk assessment, the focal point of this study is a close-up view of the micro-scale dynamics of inundation and evacuation on urban district level. The existing situation and urban setting is subsequently compared with alternative shelter options. Additionally, qualitative information on social aspects to be considered in developing appropriate mitigation options is outlined. It is anticipated to
communicate best-practice knowledge on how to approach the assessment of tsunami hazard with potential overlapping areas to other natural disasters
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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