Temporal and spatial hazard assessment for a future eruption of Taal Volcano, Philippines

Taal Volcano is the smallest active volcano in the world yet has produced some of the deadliest eruptions in history. Its close proximity to a large population and the possibility that a large magnitude volcanic eruption could occur once again is worrying. To date, no published hazard assessment exists specifically for Taal. Here I present a first attempt to assess the hazards at Taal temporally and spatially. The temporal assessment was done by constructing a probability event tree, using HASSET, to constrain the range of probable eruption scenarios for different forecast time intervals, using available historical data for eruptions at Taal. The most probable eruption scenario for each time interval was identified and they turn out to be the same, for 4 out of 5 time intervals. Spatial assessment was done for tephra fallout hazard, using Tephra2 model. The model was run using one fixed set of ESPs which were obtained from a past VEI 4 eruption at Taal and also an analogous eruption at Sakurajima. The probability of experiencing fallout at Taal is presented in the form of probability maps, isomass maps and hazard curves. Results indicate a westward dispersal of tephra, and thus, cities located towards the west and south-west of the vent are more prone to experiencing tephra fallout, given a VEI 4 eruption happen at Taal. This first attempt to assess the hazards at Taal is one step forward to quantifying them and would be useful results for the local government when planning land-use and evacuation, to better prepare for future volcanic crises.Bachelor of Science in Environmental Earth Systems Scienc