Recent shallow seismic profilling survey by the Geological Research and Development Centre in cooperation with the Navy (AL) resulted in subsurface bottom sections which give for the first time an insight on the subsurface geology in the vicinity of the Krakatau-group (Akil and Lubis, S., 1983; Sukardjono, 1983).
Our earth as a fascinating space ship proves to be ever more so the more we learn about it. We evoloved here, it is our planet and our home, but alas, we only have a very limited direct experience of its past history.
Krakatau's eruptive activity reawakened as submarinu on December 29th, 1927, and after several brief pf longer cyclus of erosion and denudation the volcano finally rose above sea level definitely between Augst 11th - September 10th, 1930 as Anak Krakatau IV.