講演情報
[O09-P09]Does the morphology of meteorite craters change depending on the bedrock topography? Experiments on impact craters using potato starch★Invited Papers
*春日 佑善1、澤田 一輝1、小川 雅斗1、栗林 司1、阿部 琉雅1、常 美妃1、河﨑 航1、千葉 渉生1、杉田 開1、熊谷 一郎1 (1.明星大学)
キーワード：
クレーター、地形、実験、火星
The numerous craters found on the surfaces of the Moon and Mars provide crucial clues for interpreting geological information. Traditionally, it has been considered that the crater shape is primarily determined by impact conditions such as impact velocity, angle, and impactor mass. However, the influence of subsurface topography (bedrock topography) remains poorly understood. Here, we have experimentally investigated the influence of subsurface topography covered with a layer of sediments on crater morphology. In our experiments, the topographic model manufactured by a 3D printer was placed at the bottom of the container. Then, potato starch was deposited to the specified thickness and the surface was leveled. Subsequently, an iron sphere was released from an electromagnet and impacted on the potato starch surface. The moment of the impact and the crater formation process were captured using a high-speed video camera. We examined three types of the topographic model (flat plate, triangular grooves, and semi-circle ridges), and confirmed that the topography of the model beneath the potato starch layer clearly influenced the formation process and the resultant morphology of the crater. A circular crater was formed in case the flat plate was used, while elliptical craters were generated for the triangular grooves and semi-circular ridges. Moreover, the ejecta emplacement patterns differ between triangular grooves and semi-circle ridges. As the subsurface topography reflected in crater morphology, it is useful to unveil the hidden bedrock topography from crater observations.