Simulation Of Lava Flows Research Articles

The simulation model SCIARA: the 1991 and 2001 lava flows at Mount Etna

Cellular Automata (CA), a paradigm of parallel computing, represent an alternative to differential equations for modelling and simulating very complex phenomena, whose evolution is based on local interactions of their constituent parts. A CA model for lava flow simulations, SCIARA (‘Simulation by Cellular Interactive Automata of the Rheology of Aetnean lava flows’) was developed and improved according to an empirical CA method for simulating macroscopic phenomena. Its last version, SCIARA-hex1, was applied to the 1991 lava flow of the 1991–1993 eruption of Etna. The simulation results are satisfying within limits to forecast the lava flow path. It was also applied during the eruption of Etna in the summer of 2001, when a new eruption threatened the town of Nicolosi. This ‘real time’ application proved that SCIARA is a reliable and flexible tool for forecasting lava flow paths and for assessing hazard in the Etnean area.

Lava Flow Simulation for the Disaster Area of the Volcano Eruption

Japan is the eminent volcanic country in the world, and Suwanose-jima in Kagoshima and Mt. Asama in Gunma are puffing out smoke vigorously at present. In the past, the large-scale eruptions occurred in Sakura-jima and Unzen-Fugendake, and 10 percent of the energy in the earthquake and the volcano eruption of the whole earth is released in Japan. Therefore the prediction for the flow area of lava is very important. Then, we try to develop the simulation system which predicts the flow area of lava and the people want to use it at their homes. Because of this, our system must be able to use on a PC becoming popular in the present time. Our simulation technique can reduce the computing time using the simple way without considering the viscosity dynamics and so on. Also this system can show the simulation result with the three dimensional image and the animation using OpenGL. The user can view the area of the lava flow from the various angles, and we think that this is useful for the improvement of their conscience for the disaster prevention.

Particle-based Visual Simulation of Lava Flows

本論文では，粒子ベースの溶岩流のビジュアルシミュレーション法を提案する．本手法では，粘性流体と熱移動のシミュレーションを基本として，溶岩流の特徴である，流れが扇状に広がる，温度によって粘性率が変化し冷却によって固化する，温度によって色が変化し溶岩流表面にクラストと呼ばれる黒く固化した部分が生じる，クラストが崩壊し明るい溶岩流が流出する，などの現象の表現を可能としている．

Simulating lava flows by an improved cellular automata method

Lava-flow morphology is determined by cooling rate, viscosity, yield strength, eruption rate, topography, total mass, and other various factors. We have made a numerical flow model, assuming nonisothermal laminar Bingham flow, in which we take the self-gravity and cooling mechanisms into account. Because the calculation method is a type of cellular automata on square meshes, we can apply our numerical model on any actual topography based on a dense-grid digital elevation model. A method of eliminating the mesh shape dependence, which is a well-known problem of cellular automata, is also presented. This reduced random space method enables us to calculate large-scale lava flows in a short time without numerical instability, and obtain mesh-free reliable results. This method is applicable to any other cellular automata type algorithm with ease. We validate our simulation code using data from a real lava flow.

Cellular automata for simulating lava flows: A method and examples of the Etnean eruptions

Abstract This paper presents a bidimensional cellular model for simulating lava flows and its application to the simulation of the 1986–87 and 1991–92 Etnean eruptions. Lava flow is viewed as a dynamic system based on local interactions with discrete time and space, where space is represented by square cells. Each cell is characterized by specific values (the state) of the following selected physical parameters: altitude, lava thickness, lava temperature and lava outflows toward the neighbouring cells. Lava rheology is considered indirectly through its effect on lava thickness. The boundary values constraining a simulation are those describing underlying topography, lava discharge rate, eruption temperature, solidus temperature and rheology. The Cellular Automata model has been tested against growth data for Etna's 1986–87 and 1991–92 flow fields. Even though the data set is heterogeneous, the model and real flow field show strikingly similar growth patterns. The close similarity highlights the flexibility of the Cellular Automata approach; as a matter of fact it should be noted that the cell dimension can be chosen in order to define the approximation, to which the simulation must be developed and topography can be easily updated on account of solidification thanks to the discrete specification for space and time, thus allowing the simulation of multiple flows. first deals with the reduction of the dimension of the cells from 10 m to 5 m. This scale is better adapted to the study of medium and small events. The second is linked to the evolution of the transition algorithm so as to modify certain types of behaviour, such as tunneling, not easy to simulate in the current form.

玄武岩質溶岩流のシミュレーション : 1983 年三宅島溶岩流への適用

玄武岩質溶岩流のシミュレーション : 1983 年三宅島溶岩流への適用