https://www.youtube.com/watch?v=oF-YCPqCU3w
When new fissures opened northeast of the first Geldingadalir vents in early April 2021, lava fountains quickly piled scoria into small cinder cones.
Spatter and bombs that fall near the vent weld and stack overnight; under high eruption rates a cone’s rim can rise meters in a single day before collapses reshape it again.