Publication Date:
2023-06-08
Description:
Pyroclastic density currents (PDCs) that escape their confining channels are among the most dangerous of volcanic hazards. These unconfined PDCs are capable of inundating inhabited areas that may be unprepared for these hazards, resulting in significant loss of life and damage to infrastructure. Unconfined PDCs can be categorized based on some of their primary dynamic characteristics (e.g., velocity, concentration, dynamic pressure, temperature), which also determine the impacts that they have on humans and infrastructure. Here, we used impact assessments following eruptions at Merapi (Indonesia) in 2010 and Fuego (Guatemala) in 2018 to better understand the dynamics of the PDCs during the eruptions. By analyzing these and similar events, we identified four main categories of unconfined PDC based on their dynamic characteristics: 1. fast overspill flows, 2. slow overspill flows, 3. high-energy surges, and 4. low-energy detached surges (LEDS). How we treat the uncertainty associated with forecasting the inundation area of these PDCs (e.g., in modelling) significantly impacts hazard planning for areas prone to volcanic eruptions. We provide an example of this using hazard modelling of lava dome collapse PDCs from several high-risk volcanoes in Southeast Asia, which show a difference in the projected impacts depending on the overspill buffer with which the PDC is modelled.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
