Abstract
Volcanic ash is an increasingly common, long-range hazard, impacting on our globalised society. The Asia-Pacific region is rapidly developing as a major contributor to the global population and economy and is home to one-quarter of the world’s active volcanoes. Here we present a regional-scale volcanic ash hazard assessment for the Asia-Pacific using a newly developed framework for Probabilistic Volcanic Ash Hazard Analysis (PVAHA). This PVAHA was undertaken using the Volcanic Ash Probabilistic Assessment of Hazard (VAPAH) algorithm. The VAPAH algorithm considered a magnitude-frequency distribution of eruptions and associated volcanic ash load attenuation relationships for the Asia-Pacific, and integrated across all possible events to arrive at an annual exceedance probability for sites of interest. The Asia-Pacific region was divided into six sub-regions (e.g. Indonesia, Philippines and Southeast Asia, Melanesia/Australia, Japan/Taiwan, New Zealand/Samoa/Tonga/Fiji and Russia/China/Mongolia/Korea) characterised by 276 source volcanoes each with individual magnitude-frequency relationships. Sites for analysis within the Asia-Pacific region were limited to land-based locations at 1-km grid spacing, within 500 km of a volcanic source. The Indonesian sub-region exhibited the greatest volcanic ash hazard in the region at the 100-year timeframe, with additional sources (in Japan, the Philippines, Papua New Guinea, Kamchatka - Russia and New Zealand) along plate boundaries manifesting a high degree of hazard at the 10,000-year timeframe. Disaggregation of the volcanic ash hazard for individual sites of interest provided insight into the primary causal factors for volcanic ash hazard at capital cities in Papua New Guinea, the Philippines and Japan. This PVAHA indicated that volcanic ash hazard for Port Moresby was relatively low at all timeframes. In contrast to this, Jakarta, Manila and Tokyo are characterised by high degrees hazard at all timeframes. The greatest hazard was associated with Tokyo and the PVAHA was able to quantify that the large number of sources impacting on this location was the causal factor contributing to the hazard. This evidence-based approach provides important insights for decision makers responsible for strategic planning and can assist with prioritising regions of interest for more detailed volcanic ash hazard modelling and local scale planning.
Highlights
Explosive eruptions pose a serious hazard to both society and the environment (Blong 1984; Spence et al 2005; Horwell and Baxter 2006; Durant et al 2010; Wilson et al 2012)
The Volcanic Ash Probabilistic Assessment of Hazard (VAPAH) algorithm combines magnitudefrequency relationships, a catalogue of Ash Load Prediction Equations (ALPEs) and global scale meteorological conditions for a region of interest and integrates across all possible events to arrive at a preliminary annual exceedance probability for each site across the region of interest
The Indonesian sub-region is subjected to a prevailing easterly wind and has 74 sources contributing to the hazard at this regional scale, more than any other subregion
Summary
Explosive eruptions pose a serious hazard to both society and the environment (Blong 1984; Spence et al 2005; Horwell and Baxter 2006; Durant et al 2010; Wilson et al 2012). The potential impacts of volcanic ash fallout are widespread, varying and highly dependent on the scale of the eruption and the distance from source (Blong 1984; Heiken et al 1992; Spence et al 2005; Horwell and Baxter 2006; Costa et al 2009; Durant et al 2010) These impacts include but are not limited to: (1) damage to human settlements and buildings in the form of roof collapse from ash loading; (2) disruption of transportation systems due to a decrease in or loss of visibility, covering of roads/railways by ash or direct damage to vehicles; (3) partial or total destruction of agricultural crops, damage to forestry, decrease in soil permeability and increased surface run-off promoting flooding; (4) destruction of pastures and health risks for livestock (e.g. fluorosis); (5) disruption of communication systems (e.g. equipment and power lines); (6) temporary shutdown of airports due to degraded engine performance, failure of navigation equipment or loss of visibility; (7) volcanic ash leaching, which can lead to chemical and physical changes in the quality of open water supplies; (8) adverse health effects (e.g. irritation of eyes and skin and potential respiratory symptoms) associated with ash inhalation. These potential impacts stress the socio-economic implications of volcanic ash fallout and highlight the relevance of adequate hazard assessment and risk mitigation (Folch et al 2008a; Folch et al 2008b; Folch and Sulpizio 2010)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
