September 19, 2025 – A lava bomb from the north vent

A lava bomb from the north vent above the crater rim that was found not long after it landed and cooled. As the molten bombs fly through the air, they cool and form a glassy crust with the interior full of vesicles. Most shatter into many pieces upon impact with the ground, but on rare occasions some stay mostly intact. Bombs like this one can be analyzed to help geologists understand where the magma is coming from and the processes necessary to bring it to the surface. Photo by USGS geologist D. Downs.