Friday, September 19, 2008
Welcome
Thankyou for clicking on my blog. READ ON TO LEARN MORE ABOUT VOLCANOES! If you decide to read on (please do ;) ), I hope it will improve your knowledge of volcanoes of the volcanic variety. Please feel free to leave a comment saying how brilliant and interesting my blog is.
The Basics
--->A volcano is a vent that connects the magma chamber to the Earth's surface. The magma chamber of a volcano contains MAGMA, rock made molten by high temperature and pressure within the Earth. As pressure in the magma chamber builds up, it needs somewhere to go and therefore the volcano ERUPTS. After the magma flows out of the Earth's surface, it is called LAVA.
Image Source: www.greenpeace.org
Thursday, September 18, 2008
Did You Know...
There are more than 1,500 ACTIVE volcanoes (volcanoes that have recently erupted and will likely erupt again) on the Earth today, 80 of which are underwater.
Wednesday, September 17, 2008
Tuesday, September 16, 2008
Did You Know...
The majority of the Earth's Volcanoes above sea level encircle the Pacific Ocean in the Pacific Ring Of Fire.
Image Source: www.bolehtau.files.wordpress.com
Before They Erupt
Scientists can usually tell if a volcano is about to erupt:
-As the magma moves nearer the surface, it releases gases. These gases have quite a bad odour and the smell lingers in the air surrounding the volcano. One of the gases released would be sulfur dioxide; an increase in the level of sulfur dioxide in the air can be detected by a correlation spectrometer.
-There can also be small earthquakes/vibrations caused by the movement of magma. These can be detected by a seismograph.
-The sides of a volcano can also swell/bulge outwards due to magma gathering in the magma chamber. These can be measured by geodimeters.
Image Source: www.astronet.ru
Monday, September 15, 2008
When They Erupt
Volcanic eruptions can be destructive and also creative.
We can usually predict when a volcano is about to erupt as the sides of the volcano bulge outwards. Earthquakes are also quite likely to happen before a volcano erupts. There are also gaseous fumes which smell really bad.
The magma builds up in the chimney of the volcano and mixes with the gases from the melted rocks. This mixture then rises to the top of the chimney and explodes out of the cone.
Dust, steam, gas and hot rocks explode out of the cone. These hot rocks are also known as volcanic bombs. These can be the size of a house and be hurled miles away from the volcano, though there can also be smaller fragments which are hurled even further and be just as destructive.
Lava (hot molten rock in liquid form) flows out of the chimney. The thicker the lava, the slower it flows and doesn't usually travel far and forms large rocks when it cools. The lighter the lava the faster and further it flows. Lava incinerates anything in it's path.
Volcanoes also release gases such as hydrogen and carbon dioxide. When hydrogen and oxygen mix, they form water vapour which contributes to the water cycle. Carbon dioxide is used by plants to make food.
The dust and ash released from volcanoes can act as fertilizer for the soil surrounding the volcano area.
We can usually predict when a volcano is about to erupt as the sides of the volcano bulge outwards. Earthquakes are also quite likely to happen before a volcano erupts. There are also gaseous fumes which smell really bad.
The magma builds up in the chimney of the volcano and mixes with the gases from the melted rocks. This mixture then rises to the top of the chimney and explodes out of the cone.
Dust, steam, gas and hot rocks explode out of the cone. These hot rocks are also known as volcanic bombs. These can be the size of a house and be hurled miles away from the volcano, though there can also be smaller fragments which are hurled even further and be just as destructive.
Lava (hot molten rock in liquid form) flows out of the chimney. The thicker the lava, the slower it flows and doesn't usually travel far and forms large rocks when it cools. The lighter the lava the faster and further it flows. Lava incinerates anything in it's path.
Volcanoes also release gases such as hydrogen and carbon dioxide. When hydrogen and oxygen mix, they form water vapour which contributes to the water cycle. Carbon dioxide is used by plants to make food.
The dust and ash released from volcanoes can act as fertilizer for the soil surrounding the volcano area.
WATCH BELOW
Video Source: http://youtube.com/watch?v=CgpNqrR318U
Sunday, September 14, 2008
Mt. Tambora. Indonesia. 1815
Mt. Tambora, Indonesia, is located just east of Bali and Lombok-both being popular tourist destinations.
In 1812, small quantities of steam and ash exploded from the volcano and miniature earthquakes occurred also. This continued until 5 April, 1815.
On this day, a major eruption occurred and was heard over 1000 kilometres away. Then, 10 days later, a number of major explosions took place.
Columns of volcanic material were created, stretching up to 40 kilometres into the sky. When these columns collapsed, a wave of ash, cinders and volcanic rocks swept across the island, killing up to 10,000 people instantly.
The sky became dark as the ashes and dust blocked out the sun for 3 days and was oneof the main causes for making 1816-'The Year Without A Summer'. When the ashes and dust fell to the ground, they destroyed vegetation and killed nearly up to 80,000 people by disease and famine.
This death toll is the largest caused by a volcanic eruption in history.
In 1812, small quantities of steam and ash exploded from the volcano and miniature earthquakes occurred also. This continued until 5 April, 1815.
On this day, a major eruption occurred and was heard over 1000 kilometres away. Then, 10 days later, a number of major explosions took place.
Columns of volcanic material were created, stretching up to 40 kilometres into the sky. When these columns collapsed, a wave of ash, cinders and volcanic rocks swept across the island, killing up to 10,000 people instantly.
The sky became dark as the ashes and dust blocked out the sun for 3 days and was oneof the main causes for making 1816-'The Year Without A Summer'. When the ashes and dust fell to the ground, they destroyed vegetation and killed nearly up to 80,000 people by disease and famine.
This death toll is the largest caused by a volcanic eruption in history.
Image Source: www.bayburtforum.com
Saturday, September 13, 2008
Friday, September 12, 2008
VOLCANOLOGY- the study of Volcanoes
A volcanologist is someone that studies volcanoes. Volcanology is an important job as volcanoes can be threatening to many populations today.
It is believed that 1,500 active volcanoes around the world threaten half a billion people.
There are only about 200-300 volcanologists in the world today and over the last 20 years, 23 volcanologists have been killed by volcanoes.
Image Source: www.wolfweb.unr.edu
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