2009

 
 

Gravity and air resistance help to govern the fall of particles from the atmosphere. Most particles reach a terminal velocity after a few seconds.

 

Readings

Bonadonna, C, GGJ Ernst and RSJ Sparks, 1998, Thickness variations and volume estimates of tephra fall deposits: the importance of particle Reynolds number JVGR 81 173-187.

Riley, C M, W I Rose and G J S Bluth, 2003, Quantitative shape measurements of distal volcanic ash, Jour Geophys Res 108 no B10, 2504

Rose W I, C M Riley and S Dartevelle, 2003, Sizes and shapes of 10 ma distal ashfall pyroclasts in the Ogalalla Group, Nebraska, J Geology, 111:115-124.