During a volcanic eruption, lava, ash, volcanic bombs and blocks, and gases are expelled from the volcanic vent. There are several types of eruptions defined by volcanologists, often named after volcanoes that exhibited that type. On August 26th, 1883, Krakatoa erupted catastrophically. An ash plume rose 80km into the sky and the loud bang was heard over 5,000km away. Two-thirds of the island was destroyed and 36,000 people were killed by pyroclastic flows and tsunamis up to 40m high. Volcanic eruptions can cause landslides and mudslides from instability in surrounding land and heavy rainfall on steep terrain. Wildfires are also

1. VOLCANIC ERUPTION
During a volcanic eruption, lava, (ash, volcanic bombs and blocks), and various gases are expelled
from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by
volcanologists. These are often named after famous volcanoes where that type of behavior has
been observed. Some volcanoes may exhibit only one characteristic type of eruption during a
period of activity, while others may display an entire sequence of types all in one eruptive series.
A volcanic eruption is the point in which a volcano is active and releases lava and poisonous gasses
in to the air. They range from daily small eruptions to extremely infrequent supervolcano
eruptions (where the volcano expels at least 1,000 cubic kilometers of material.) Some eruptions
form pyroclastic flows, which are high-temperature clouds of ash and steam that can travel down
mountainsides at speeds exceeding that of an airliner.
Worst volcanic eruption: 1883 Krakatoa eruption, Indonesia
The force of the explosive eruption of Krakatoa was 10,000 times greater than the hydrogen bomb
that was dropped on the city of Hiroshima. In fact the percussive force of the blast was so great
that it is said to have travelled back and forth around the world seven times.
Though the volcano on the Indonesian island of Krakatoa had been already erupting for several
months, it came to its dramatic denouement early in the morning on 26 August 1883. At the point
of the eruption a plume of ash was blasted 80km into the atmosphere and the bang was so loud
that it was heard more than 3000km away in Perth and more than 5000km in the opposite
direction on the Indian Ocean island of Rodrigues. Two thirds of the island was destroyed. 36,000
people were killed by superheated flows of gas and ash that swept across neighbouring islands
and also by a series of devastating tsunamis up to 40m high.
A landslide is a disaster involving elements of the ground, including rocks, trees, parts of houses,
and anything else which may happen to be swept up. Landslides can be caused by an earthquake,
volcanic eruptions, or general instability in the surrounding land. Mudslides or mudflows, are a
special case of landslides, in which heavy rainfall causes loose soil on steep terrain to collapse and
slide downwards.
Wildfires, or forest fires, are uncontrolled fires burning in wildland areas. Common causes include
lightning, human carelessness, arson, volcano eruption, and pyroclastic cloud from active volcano.
The can be a threat to those in rural areas and also to wildlife. Wildfires can also produce ember
attacks, where floating embers set fire to buildings at a distance from the fire itself.