lahar

plural lahars

1. geographyA volcanic mudflow.

   A regime of persistent lahar activity results when eruptive activity continually supplies unconsolidated volcanic material for remobilization.

   2006, Andrew J. L. Harris et al., “Downstream aggradation owing to lava dome extrusion and rainfall runoff at Volcán Santiaguito, Guatemala”, in William Ingersoll Rose, editor, Volcanic Hazards in Central America, page 86

   2 more examples

   Such a highly destructive mud-flow (termed a lahar) eventually stops as a pile of debris of all shapes and sizes, as mixed up as a glacial moraine; the two deposits have often been confused.

   1985, Jocelyn Thornton, Field Guide to New Zealand Geology, page 204

   Pyroclastic flows are often difficult to distinguish in outcrops from a similar type of fragmental debris flow known as lahars. Both are characteristically unstratified and unsorted. A deposit containing blocks of varied compositions with rounded shapes is more likely to have been formed by a lahar than by a glowing avalanche.

   2000, Jacques-Marie Bardintzeff, Alexander R. McBirney, Volcanology, page 138