USGS auf Twitter: "Today is #InternationalDayofMathematics! Check out one of our past #CalderaChronicles that explains how you can determine the height of a geyser eruption. All it takes is a simple tool and a little bit of #math to figure it out! https://t.co/VahkEKTLnF @USGSVolcanoes https://t.co/4v5tSKLXjK" / Twitter