Simple Calculator of Ballistic Trajectories for Blocks Ejected during VolcanicEruptions

摘要

During the past century, numerous observers have described the violent ejectionof large blocks and bombs from volcanoes during volcanic explosions. Minakami (1942) mapped the locations of blocks ejected from Asama Volcano during explosions in 1937. He developed a mathematical expression relating initial velocity and trajectory angle of ejected blocks to the ejection distance, taking into account air drag and assuming a constant drag coefficient. In this paper, I describe a program that can be used for quick ballistics calculations. The program, Eject, was written in Microsoft Visual Basic and operates on any personal computer running Microsoft Windows 95 or later.