1:45 PM - 3:15 PM
[O11-P114] Simulation of Lava Flow at Mihara Volcano, Izu-Oshima, using a Terrain Model Created by a 3D Printer
Keywords:Simulation of Lava Flow, 3D printer, Izu Oshima
ⅠBackground and Objective
Izu Ōshima (Figure 1) is a volcanic island formed approximately 50,000 years ago. About 1,700 years ago, a large-scale flank eruption created a caldera. Subsequently, in a major eruption in 1777, the central cone, Mt. Mihara, was formed. Over the past 150 years, moderate-scale eruptions have occurred in 1876, 1912, 1950, and 1986, approximately every 37 years (Izu Ōshima Geopark Promotion Committee, 2024). Considering that it has been 39 years since the last eruption, another eruption is expected to occur in the near future.
Ishikawa et al. (2004) stated that the development of simulation systems for predicting lava flow areas can raise awareness of disaster prevention. Furthermore, Sato et al. (2024) conducted a basic study using computer simulations on evacuation on foot in the event of a lava flow from a Mt. Fuji eruption, demonstrating the importance of reducing the time taken to begin evacuation for safety. While many studies have focused on computer-based lava flow simulations, predicting the exact eruption site on Izu Ōshima is particularly difficult. Therefore, using analog experiments with physical terrain models to quickly and easily predict the direction and extent of lava flow in the event of an eruption is considered a highly effective method for planning evacuation strategies.
This study aims to clarify how lava would flow in the event of a future eruption at Mt. Mihara, using simulations conducted on a terrain model created with a 3D printer.
ⅡMethodology
(1) Creation of the Terrain Model
Data for 3D printing was downloaded from the Geospatial Information Authority of Japan (Figure 2) and printed (Figure 3). A scale of 1:26,667 was used, where 4 km in actual distance corresponds to 15 cm on the model.
(2) Lava Flow Model
Referring to the experiment by Chiba et al. (2017), rinse-in shampoo (hereinafter referred to as “shampoo”) was used to simulate lava. Shampoo can be mixed with water to adjust its viscosity. Based on the scale of the model used in this study, a mixture of shampoo and water in a 7:4 ratio was used to create the lava flow model.
(3) Lava Flow Simulation
Using a burette, the lava flow model was poured into the crater at regular intervals. The speed and range of the lava flow were observed and recorded.
ⅢResults
(1) Creation of the Terrain Model
As shown in Figure 3, the terrain model was successfully created.
(2) Lava Flow Simulation
(i) Summit Crater (Crater A)
The lava flow model was poured into the crater at a rate of 0.02 g/s (Figure 4). Up to 1.8 g, the flow remained within and around the crater. Once the volume exceeded 1.8 g, the lava began to flow northwest. It took 53 seconds to reach a point 1.4 km from the crater, which corresponds to a model flow speed of 0.1 cm/s.
(ii) Flank Craters
Among the three aligned flank craters, lava flow simulations were conducted at the southernmost crater (Crater Bs) and the northernmost crater (Crater Bn). Crater Bs: The lava model was poured at a rate of 0.03 g/s (Figure 5). It began flowing northeast almost immediately, reaching a point 640 m away in 33 seconds, giving a model flow speed of 0.07 cm/s. Crater Bn: The lava model was poured at a rate of 0.02 g/s (Figure 6). It also flowed northeast immediately, reaching the same 640 m point in 46 seconds, with a model speed of 0.05 cm/s.
ⅣDiscussion
Using a 3D-printed terrain model and a shampoo-based lava flow model, it was possible to clarify the direction and speed of lava flow. In this study, the experiment was conducted only on the craters involved in the 1986 moderate eruption, but the method can be applied to any potential eruption site on Mt. Mihara.
Moreover, this terrain modeling technique can be adapted for other volcanoes, expanding its applicability. Compared to computer simulations, this analog approach offers a quicker and more accessible means of predicting lava flow range and arrival time to a given location, making it a valuable tool for disaster prevention and evacuation planning.
Izu Ōshima (Figure 1) is a volcanic island formed approximately 50,000 years ago. About 1,700 years ago, a large-scale flank eruption created a caldera. Subsequently, in a major eruption in 1777, the central cone, Mt. Mihara, was formed. Over the past 150 years, moderate-scale eruptions have occurred in 1876, 1912, 1950, and 1986, approximately every 37 years (Izu Ōshima Geopark Promotion Committee, 2024). Considering that it has been 39 years since the last eruption, another eruption is expected to occur in the near future.
Ishikawa et al. (2004) stated that the development of simulation systems for predicting lava flow areas can raise awareness of disaster prevention. Furthermore, Sato et al. (2024) conducted a basic study using computer simulations on evacuation on foot in the event of a lava flow from a Mt. Fuji eruption, demonstrating the importance of reducing the time taken to begin evacuation for safety. While many studies have focused on computer-based lava flow simulations, predicting the exact eruption site on Izu Ōshima is particularly difficult. Therefore, using analog experiments with physical terrain models to quickly and easily predict the direction and extent of lava flow in the event of an eruption is considered a highly effective method for planning evacuation strategies.
This study aims to clarify how lava would flow in the event of a future eruption at Mt. Mihara, using simulations conducted on a terrain model created with a 3D printer.
ⅡMethodology
(1) Creation of the Terrain Model
Data for 3D printing was downloaded from the Geospatial Information Authority of Japan (Figure 2) and printed (Figure 3). A scale of 1:26,667 was used, where 4 km in actual distance corresponds to 15 cm on the model.
(2) Lava Flow Model
Referring to the experiment by Chiba et al. (2017), rinse-in shampoo (hereinafter referred to as “shampoo”) was used to simulate lava. Shampoo can be mixed with water to adjust its viscosity. Based on the scale of the model used in this study, a mixture of shampoo and water in a 7:4 ratio was used to create the lava flow model.
(3) Lava Flow Simulation
Using a burette, the lava flow model was poured into the crater at regular intervals. The speed and range of the lava flow were observed and recorded.
ⅢResults
(1) Creation of the Terrain Model
As shown in Figure 3, the terrain model was successfully created.
(2) Lava Flow Simulation
(i) Summit Crater (Crater A)
The lava flow model was poured into the crater at a rate of 0.02 g/s (Figure 4). Up to 1.8 g, the flow remained within and around the crater. Once the volume exceeded 1.8 g, the lava began to flow northwest. It took 53 seconds to reach a point 1.4 km from the crater, which corresponds to a model flow speed of 0.1 cm/s.
(ii) Flank Craters
Among the three aligned flank craters, lava flow simulations were conducted at the southernmost crater (Crater Bs) and the northernmost crater (Crater Bn). Crater Bs: The lava model was poured at a rate of 0.03 g/s (Figure 5). It began flowing northeast almost immediately, reaching a point 640 m away in 33 seconds, giving a model flow speed of 0.07 cm/s. Crater Bn: The lava model was poured at a rate of 0.02 g/s (Figure 6). It also flowed northeast immediately, reaching the same 640 m point in 46 seconds, with a model speed of 0.05 cm/s.
ⅣDiscussion
Using a 3D-printed terrain model and a shampoo-based lava flow model, it was possible to clarify the direction and speed of lava flow. In this study, the experiment was conducted only on the craters involved in the 1986 moderate eruption, but the method can be applied to any potential eruption site on Mt. Mihara.
Moreover, this terrain modeling technique can be adapted for other volcanoes, expanding its applicability. Compared to computer simulations, this analog approach offers a quicker and more accessible means of predicting lava flow range and arrival time to a given location, making it a valuable tool for disaster prevention and evacuation planning.