What s the difference between magma and lava

A.� Nothing, they're the same thing. The two different terms are used to distinguish between molten rock that's still beneath the earth's crust: magma, and molten rock that's erupted: lava.

�

Q.� How can objects, like lava trees, be formed, why don't they just incinerate as soon as the lava touches them

A.� Quite a number of things have been preserved in lava.

�

When the lava comes in contact with the tree it cools very quickly, technically known as 'quenching'. A crust forms between the liquid lava and the object. This crust is hot but it insulates the tree from the extreme heat of the flow.

�

Eventually, the tree does get incinerated; it just takes a little longer, by this time though the crust of lava has formed the shape of the original object.

�

Q.� What is lava made of

A.� Lava is made of the elements silicon, oxygen, aluminium, iron, magnesium, calcium, sodium, potassium, phosphorus, and titanium, plus other elements in very small concentrations.

�

Q.� What does 'lava' mean

A.� The word lava comes from the Italian word for avalanche, which is based on the Latin word "labes" which translates as 'sliding down'. This is probably in reference to the front of lava flows where clinker is continuous falling down.

�

Q.� How hot is lava

A.� The temperature varies according to the chemical composition.

�

Hawaiian lava can reach temperatures of around 1100 C, whereas that of Mount Saint Helens is around 800 C.

�

Q.� How fast does lava flow

A.� Once the flow of lava has become established and good channels have been developed, lava can move at speeds of 60km an hour.

�

Q.� Why is lava different colours

A.� The colour of lava depends on its temperature. At the beginning, when it's really hot, around 1000-1150 C, it starts out bright orange. It changes to bright red when it cools down to 800-1000 C. When it’s dark red it is 650-800 C before cooling to around 500-650 C, which is brownish red.

�

Solid lava is black, but can still be very hot.

�

Do you want to question The AnswerBank about a natural event

�

by Lisa Cardy