Global database on large magnitude explosive volcanic eruptions (LaMEVE)

© 2012 Crosweller et al. To facilitate the assessment of hazards and risk from volcanoes, we have created a comprehensive global database of Quaternary Large Magnitude Explosive Volcanic Eruptions (LaMEVE). This forms part of the larger Volcanic Global Risk Identification and Analysis Project (VOGRIPA), and also forms part of the Global Volcano Model (GVM) initiative (www.globalvolcanomodel.org). A flexible search tool allows users to select data on a global, regional or local scale; the selected data can be downloaded into a spreadsheet. The database is publically available online at www.bgs.ac. uk/vogripa and currently contains information on nearly 3,000 volcanoes and over 1,800 Quaternary eruption records. Not all volcanoes currently have eruptions associated with them but have been included to allow for easy expansion of the database as more data are found. Data fields include: Magnitude, Volcanic Explosivity Index (VEI), deposit volumes, eruption dates, and rock type. The scientific community is invited to contribute new data and also alert the database manager to potentially incorrect data. Whilst the database currently focuses only on large magnitude eruptions, it will be expanded to include data specifically relating to the principal volcanic hazards (e.g. pyroclastic flows, tephra fall, lahars, debris avalanches, ballistics), as well as vulnerability (e.g. population figures, building type) to facilitate risk assessments of future eruptions

The Volcanic Hazards Assessment Support System for the Online Hazard Assessment and Risk Mitigation of Quaternary Volcanoes in the World

Volcanic hazards assessment tools are essential for risk mitigation of volcanic activities. A number of offline volcanic hazard assessment tools have been provided, but in most cases, they require relatively complex installation procedure and usage. This situation causes limited usage of volcanic hazard assessment tools among volcanologists and volcanic hazards communities. In addition, volcanic eruption chronology and detailed database of each volcano in the world are essential key information for volcanic hazard assessment, but most of them are isolated and not connected to and with each other. The Volcanic Hazard Assessment Support System aims to implement a user-friendly, WebGIS-based, open-access online system for potential hazards assessment and risk-mitigation of Quaternary volcanoes in the world. The users can get up-to-date information such as eruption chronology and geophysical monitoring data of a specific volcano using the direct link system to major volcano databases on the system. Currently, the system provides 3 simple, powerful and notable deterministic modeling simulation codes of volcanic processes, such as Energy Cone, Titan2D and Tephra2. The system provides deterministic tools because probabilistic assessment tools are normally much more computationally demanding. By using the volcano hazard assessment system, the area that would be affected by volcanic eruptions in any location near the volcano can be estimated using numerical simulations. The system is being implemented using the ASTER Global DEM covering 2790 Quaternary volcanoes in the world. The system can be used to evaluate volcanic hazards and move this toward risk-potential by overlaying the estimated distribution of volcanic gravity flows or tephra falls on major roads, houses and evacuation areas using the GIS-enabled systems. The system is developed for all users in the world who need volcanic hazards assessment tools

How Many Explosive Eruptions are Missing from the Geologic Record? Analysis of the Quaternary Record of Large Magnitude Explosive Eruptions in Japan

Large magnitude explosive eruptions in Japan were compiled for the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database. Here we use this dataset to investigate the under-recording of Japanese explosive eruptions. We identify under-recording of Volcanic Explosivity Index (VEI) 4–5 eruptions on two timescales. Model fitting and Akaike’s information criterion (AIC and AICc) model selection suggest that these trends can be represented with the double exponential decay model, reflecting geologic processes. The time series of the recording rate of larger eruptions (VEI 6 and 7) show a slowly decreasing trend in comparison to smaller eruptions. These time series can be represented with the single exponential decay model. The percentages of missing eruptions are estimated from the fitted models. Our results show an inverse correlation between VEI and degree of under-reporting suggesting that even larger VEI eruptions are under-recorded in the Quaternary. For example, 89 % of VEI 4 events, 65–66 % of VEI 5 events, 46–49 % of VEI 6 events and 36–39 % of VEI 7 events are missing from the record at 100 ka, 200 ka, 300 ka, and 500 ka, respectively. Comparison of frequencies of Japanese and global eruptions suggests that under-recording of the global database is 7.9–8.7 times larger than in the Japanese dataset. Therefore, under-recording of events must be taken into account in estimating recurrence rates of explosive eruptions using the geologic record