1 In some cases lahars travel large distances and form thick deposits up to tens of metres deep.

2 In 1953 a lahar swept away a railway bridge at Tangiwai at the base of the mountain and 151 people were killed when an Auckland-to-Wellington train plunged into a river.

3 In March 2007 a mudflow, or "lahar" flowed down the side of the mountain after the crater lake overflowed, and large eruptions in 1995 and 1996 blanketed the surrounding area in ash.

4 lahar—an avalanche of volcanic ash and rock mixed with water—50 kilometers (30 miles) down the west side of the volcano summit.

5 The dried, hardened remains of the lahar persist today, a streak of barren rock on a landscape that is otherwise richly vegetated.

6 Another lahar in 1953 caused New Zealand's worst rail disaster, killing 151 people.

7 Thousands of hectares of snake fruit plantations in Yogyakarta may turn arid after six irrigation dams were damaged by lahar following recent volcanic eruptions on Mount Merapi.

8 Concern has responded to several disasters over the years, including the 1991 eruption of Mt. Pinatubo and the subsequent lahar flows, which lasted for more than five years.

9 The problem is also compounded by the still present threat of lahar. If the dams are repaired, they could be hit by fresh lahar, he added.