The avalanche deposit consists mostly of loose material such as ash, lapilli, pumice, with only a few lithic blocks. This loose consistency may explain the lack of megablocks. Its total volume is about , less than the volume of the Mount St. Helens and Socompa deposits. It is comparable to the volume of the landslide that the Ancash earthquake triggered on Huascarán in Peru in 1970, resulting in more than 20,000 fatalities. Evidence points to previous flank collapses at Lastarria.