Doming results in radial fractures and subordinate concentric reverse faults which propagate divergently from the chamber upwards with increasing dilation. The structural dome so produced is characterised bysteepening in the periphery, whereas the broadening apex subsides.
Pure evacuation causes the chamber roof to collapse along adjacent bell-shaped reverse faults.
The third set of experiments focused on the structural interaction of cyclic inflation and subsequent moderate deflation. Following doming, caldera subsidence produces concentric faults that characteristically crosscut radial cracks of the dome. This superimposed fault pattern also extends inside the caldera.