1,721,092 research outputs found
An initial assessment of volcanic meteo-tsunami hazard in the South China Sea: what we learned and how to move forward
No full textVolcanic meteo-tsunamis (VMTs), though rare, can pose significant threats to people, as exemplified by the 2022 Hunga Tonga–Hunga Ha’apai (HT-HH) eruption in the SW Pacific. While various studies have explored such phenomena, none have investigated analogous scenarios in regions with potential occurrence of large undersea eruptions. We focus on areas along the South China Sea (SCS), which is a region among the most densely populated on Earth and historically prone to volcanic activity. We simulated VMTs from one intra-basin volcano (KW-23612) and three extra-basin volcanoes (Banua Wuhu, Kikai, and Fukutoku-Oka-no-Ba), to assess which countries around the SCS could be more exposed to such phenomena. Our results generally indicate that the SCS can be considered a low-hazard region from VMTs, and that the worst-case scenarios are produced by eruptions/tsunamis from within the SCS basin itself, with offshore waves up to 10 and 20 cm offshore Hong Kong and Manila respectively. Countries bordering the shallower Sunda Shelf (Malaysia, Thailand, Cambodia, and southern Vietnam), instead, receive much smaller waves (<2 cm). Despite the limitations, this study sets the basis to quantitatively assess hazard from volcanic meteo-tsunamis at key locations in the SCS
Numerical modelling of gravel transportation by a tsunami with the extended XBeach-G
Full text linkEstimating coastal erosion by a tsunami is essential for land use planning, assessing hazards for current structures (e.g., coastal nuclear power plants), and for paleotsunami reconstruction. Such estimations are currently available only for sandy beaches, using sand sediment transport models, which are not applicable to gravel beaches, which are the most common beach type in high-latitude settings. This study extended the one-dimensional cross-shore XBeach-G model to account for two-dimensional gravel transport by a tsunami. First, this study confirmed that the extended XBeach-G model can simulate a time series of waveforms of solitary waves during laboratory experiments. The proposed model was then applied to gravel transport by the 2011 Tohoku-oki tsunami at Koyadori, Japan, and found that the simulation results were consistent with observations of gravel deposits in previous studies. It was revealed that infiltration and exfiltration have an impact on morphological change caused by a tsunami on gravel coasts. In the simulation, inundation depth over land by the tsunami increased due to groundwater exfiltration, which increased the onshore deposition volume of gravel tsunami deposits. The groundwater flow calculation has not been incorporated so far for tsunami modelling, but this is important for modelling tsunami inundation at gravel beaches and gravel sediment transport by a tsunami. However, choosing appropriate values for the sediment friction factor and multiplier in the equation for gravel transport is more critical to reproducing the deposition of gravel sediments by a tsunami because these parameters are more sensitive than the parameter of groundwater flow. Although the presented model has been developed for tsunami simulation on any gravel beach, further testing and validation are recommended
Funwave-based open-access mapping applications (FUNMAP) applied to Tsunami modelling from the Manila Trench to Manila Bay, Philippines
No full textDeveloping user-friendly applications bridges the gap between models and target users, aiding in more efficient learning and optimizing workflow. In this study, we contribute to bridging this gap in the tsunami modelling community by developing two offline, free standalone applications: the Input and Output FUNMAP apps. These tools are built on the open-source Fully Nonlinear Boussinesq Wave Model - Total Variation Diminishing version (FUNWAVE-TVD), a well-established and extensively validated model. The Input app assists in setting up simulation input files and running the FUNWAVE executable, while issuing visual warnings to help prevent errors. The Output app processes simulation results to generate wave height and current maps, as well as virtual gauge plots, with export options compatible with GIS and vector editing platforms. We tested the apps using sample cases from FUNWAVE-TVD and applied them to simulate tsunami hazards in Manila Bay, Philippines, under a hypothetical Mw 8.8 earthquake scenario along the southern Manila Trench. The results show that the presence of the submarine canyon at the bay entrance, along with the complex coastlines of Luzon, Lubang, and Mindoro Islands, influences the arrival of multiple waves in Manila Bay. The highest waves were observed at the bay entrance headlands and southern coasts, with high current velocities expected along the entire coastline. This case study demonstrates the effectiveness of the FUNMAP apps in generating tsunami simulation maps and plots
Relative sea-level data from the SEAMIS database compared to ICE-5G model predictions of glacial isostatic adjustment
Full text linkThe SEAMIS database (Mendeley data repository; https://doi.org/10.17632/wp4ctb4667.1) contains 546 relative sea-level indicators from 31 different studies within the broader Southeast Asian region including the Maldives, India and Sri Lanka. Here we compare quality-controlled and site-specific relative sea-level data from 23 studies from the SEAMIS database to a suite of ICE-5G glacial isostatic adjustment models. The relation between robust and, if applicable, tectonically corrected relative sea-level data with the broad predictions of glacial isostatic adjustment models is interpreted and discussed in the article “Holocene sea levels in Southeast Asia, Maldives, India and Sri Lanka: The SEAMIS database” [1] in Quaternary Science Reviews
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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