A Study on the Volcanic Scenario Adapting the FEP Analysis

点击翻译按钮获取中文摘要

We developed a framework of a logical method to compile an event sequence scenario describing an evolution of volcanic activity from its start to end depending deductive analysis based on causality relationship between primitive physical or chemical processes governing the volcanic phenomena. We adopted FEP Matrix (Feature, Event and Process) analysis method developed in the field of high level nuclear waste repository management as a tool to analyze logical relationship between volcanic processes. Firstly we listed the most important requirements that a volcanic scenario should satisfy; they are 1) comprehension and completeness, 2) traceability and accountability, 3) ease for expansion, 4) flexibility, 5) dependence on deductive reasoning and 6) affinity to computer processing. To achieve those we propose a logical algorithm in which we disassemble a volcanic event sequence into a series of primitive processes of physical or chemical nature and then reconstruct the entire sequence with a chain of primitive processes with their causality relationships. Furthermore we use a function format to represent a physical or chemical primitive process having environmental parameters and starting event as input variables and consequence event as output variable. We applied this method for the 2000 Miyakejima and 1986-87 Izuoshima eruptions and found that the whole volcanic processes are successfully described by a combination of physical and chemical primitive processes which we listed as a function set for a basaltic volcanic activity. Thus we verified the validity of our method to realize the deductive scenario compilation for volcanic eruption forecasting.