Close inspection of the deposits from Koko Crater shows the multiple episodes of explosive activity that were parts of this shallow marine eruption. Here a scientist stands next to a large bomb sag produced by a fragment of coral reef that was ejected from the terrain that existed prior to the eruption. Evidently the layers of ash (which are typically less than 1 centimeter thick) were very wet on their emplacement, since the limestone block penetrated almost a meter into the preexisting surface of the cone, only to be buried by sediments that were derived by surface wash from the eruption. Photograph courtesy of P. Mouginis-Mark. Right click here to download a high-resolution version of the image (8.71 MB) |