9:00 AM - 9:30 AM
[O08-01] Recipe of rootless cones
★Invited Papers
Keywords:rootless cone, experiment, Mars, Kitchen Earth Science
Rootless cones are volcanic features formed by explosive interactions of lava and water. When hot molten lava covers water-saturated sediments, vaporization occurs and builds a conical edifice by pyroclast ejection. This explosive phenomenon is rare in nature, and its dangerousness makes it challenging to observe closely.
Previous studies have performed experiments under controllable systems using molten basaltic rocks (e.g., Zimanowski et al., 1997) and thermite reactions (e.g., Sheridan and Wohletz, 1981). These results induced the existence of a nonlinear relationship between the magma-water mass ratio and explosivity. Although these experiments were smaller than natural phenomena, the explosions were still dangerous to observe closely.
To overcome this dilemma, we (Noguchi et al., 2018) have demonstrated a laboratory-scale lava-water interaction using syrup and baking soda. Using hot “syrup” lava and wet “baking soda” substrates, we found that Rayleigh–Taylor instability between lava and water-saturated sediments enhances the explosions. The next target was the spatial distribution of rootless cones. We (Noguchi and Nakagawa, 2025) performed an experiment to verify the self-organization in rootless cone spatial distribution, which Hamilton et al., 2010 explained by the competition of available water between explosion sites. Through the experiment, we found that the self-organization in spatial distribution may be driven by the competition of water and the competition of ascending paths in lava.
In this presentation, I review previous laboratory experiments on magma-water interactions and then introduce our works (Noguchi et al., 2018; Noguchi and Nakagawa, 2025), which especially focus on lava-water interactions.
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Noguchi et al., 2018, EPS, 70:208.; Noguchi and Nakagawa, 2025, JVGR, 458, 108221.; Sheridan and Wohletz, 1981, 212(4501), 1387-1389.; Zimanowski et al., 1997, Bull Volcanol 58:491.
Previous studies have performed experiments under controllable systems using molten basaltic rocks (e.g., Zimanowski et al., 1997) and thermite reactions (e.g., Sheridan and Wohletz, 1981). These results induced the existence of a nonlinear relationship between the magma-water mass ratio and explosivity. Although these experiments were smaller than natural phenomena, the explosions were still dangerous to observe closely.
To overcome this dilemma, we (Noguchi et al., 2018) have demonstrated a laboratory-scale lava-water interaction using syrup and baking soda. Using hot “syrup” lava and wet “baking soda” substrates, we found that Rayleigh–Taylor instability between lava and water-saturated sediments enhances the explosions. The next target was the spatial distribution of rootless cones. We (Noguchi and Nakagawa, 2025) performed an experiment to verify the self-organization in rootless cone spatial distribution, which Hamilton et al., 2010 explained by the competition of available water between explosion sites. Through the experiment, we found that the self-organization in spatial distribution may be driven by the competition of water and the competition of ascending paths in lava.
In this presentation, I review previous laboratory experiments on magma-water interactions and then introduce our works (Noguchi et al., 2018; Noguchi and Nakagawa, 2025), which especially focus on lava-water interactions.
---
Noguchi et al., 2018, EPS, 70:208.; Noguchi and Nakagawa, 2025, JVGR, 458, 108221.; Sheridan and Wohletz, 1981, 212(4501), 1387-1389.; Zimanowski et al., 1997, Bull Volcanol 58:491.