LibGuides: Natural disasters of the Asia Pacific Region: Volcanoes

What is a volcano?

Key fact of volcanoes:

A volcanoe is formed by eruptions of lava and ash.
Volcanoes are usually cone shaped mountains or hills.
When magmaMagma is molten rock. reaches the Earth's surface it is called lava. When the lava cools, it forms rock.
Volcanic eruptions can happen at destructiveThe boundary of two plates are moving towards each other. (convergent) and constructiveThe boundary of two plates are moving away from each other. (divergent) boundaries, but not at conservativeThe boundary of two plates are moving past each other. (transform) boundaries.
Some volcanoes happen underwater, along the seabed or ocean floor.

There are around 1511 active volcanoes in the world today.

Volcanoes and volcanic eruptions - BBC GCSE Bitesize This link opens in a new window
(Source of the above information)
How many volcanoes are there in the world? This link opens in a new window
How many active volcanoes are there? This link opens in a new window

Causes of volcanoes

An volcano eruption occurs when pressure in the magma chamberA collection of magma inside the Earth, below the volcanoe. forces magma up the main ventThe main outlet for the magma to escape., towards the craterCreated after an eruption blows the top off the volcanoe. at the top of the volcanoe. Some magma will also be forced out of the secondary ventSmaller outlets through which magma escapes. at the side of the volcanoe.

Inside a volcano - BBC GCSE Bitesize This link opens in a new window
(Source of the above image and information)
Volcano This link opens in a new window
What causes a volcano to erupt and how do scientists predict eruptions? This link opens in a new window

Can we predict volcanic eruptions?

Scientists who specialise in volcanoes are called volcanologistsExperts who study volcanoes.. They are growing more and more confident at predicting when volcanoes will erupt in the short-term. However, the further a volcano is from erupting, the harder it is to predict. Working out if a volcano will erupt in future years is still impossible.

As a volcano becomes active, it gives off a number of warning signs. These warning signs are picked up by volcanologists and the volcano is monitored:


Warning signs	Monitoring techniques
Hundreds of small earthquakes are caused as magma rises up through cracks in the Earth's crust.	Seismometers are used to detect earthquakes.
Temperatures around the volcano rise as activity increases.	Thermal imaging techniques and satellite cameras can be used to detect heat around a volcano.
When a volcano is close to erupting it starts to release gases. The higher the sulfur content of these gases, the closer the volcano is to erupting.	Gas samples may be taken and chemical sensors used to measure sulfur levels.

Can we predict when a volcano is going to erupt? This link opens in a new window
(Source of the above information)
Predicting eruption This link opens in a new window
Can We Predict Eruptions? This link opens in a new window

Acknowledgement

Animation of Volcanoes

Animated guide: Volcanoes This link opens in a new window
(Source of the above animation)

Pacific Ring of Fire

Chains of volcanoes and oceanic trenches form the Pacific Ring of Fire

The Pacific Ring of Fire is a string of volcanoes and earthquakes around the edges of the Pacific Ocean. The Ring of Fire is the direct result of plate tectonics. The edges of several tectonic plates meet along the Ring of Fire, resulting in most of the active volcanoes on Earth. Today The Ring of Fire is home to over 75% of the world's active and dormant volcanoes.

Ring of Fire - National Geographic Education This link opens in a new window
(Source of the above information)
The Ring of Fire - pbs.org This link opens in a new window
The Pacific 'Ring of Fire' - BBC science This link opens in a new window
Pacific Ring of Fire - geography.about.com This link opens in a new window

Sumatra Volcano 2013

Sumatra Volcano This link opens in a new window

Sumatra Volcano

Life on the Ring of Fire

What it's like to live with the threat of volcanoes.

2014 Mt Kelud Java

National Geographic News Mt Kelud Volcano This link opens in a new window
Extensive article about the Mt Kelud Volcano eruption and the consequences.
Emergency reponse to the Mt Kelud Volcano This link opens in a new window
From Relief Web, description of relief efforts for the people and communities affected by Mt Kelud eruption.
Quick response to the volcano Mt Kelud This link opens in a new window
From Cordaid, information about what the community needs and what is being done to help.