Some authors recently showed that the use of a single empirical law, a constant retarding stress, also called yield strength, is more appropriate than frictional behavior and enabled the main features of debris avalanche and pyroclastic-flow deposits
to be reproduced (Kelfoun & Druitt, 2005; Kelfoun et al., 2009).
Most amusing is the characterization of "Pyrodastic flow deposit adobe." Here, "adobe" is a Philippine colloquialism for pyroclastic-flow deposits
, misapplied by the Spaniards from their experience in the Americas, where "adobe" was bricks of sun-dried clay mixed with grass.