Transient dynamics of a 2D granular pile Patrick Mutabaruka, Krishna Kumar, Kenichi Soga, Farhang Radjai and Jean-Yves Delenne Eur. Phys. J. E, 38 5 (2015) 47 Published online: 26 May 2015 DOI: 10.1140/epje/i2015-15047-x