Lahars are hot mudflows caused by the mixing of volcanic ash and rain which flow down the ash-clogged slopes of an explosive volcano (they are just mudflows after the eruption has stopped). The eruption of a volcano can create lahars. What are lahars?
1) Mudflows caused by volcanic ash and rain
2) Hot mudflows caused by volcanic ash and rain
3) Mudflows that occur during volcanic eruptions
4) Mudflows that occur after volcanic eruptions