Seems the Earth has got a lot on its plate

QUESTION Who named the original supercontinents of Pangea and Gondwanaland?

THE geological theory of plate tectonics seeks to explain how the continents came about.

It’s believed that a supercontinent called Pangea (or Pangaea) formed 270million years ago, before splitting into Gondwanaland (which later became Antarctica, India, Australia, South America and Africa) and Laurasia (North America, Europe and Asia).

The Earth’s surface is seen as a series of plates that have been moving away and towards each other for years.

Gondwana was coined in 1872 by Henry Medlicott for sedimentary rocks in central India, in the ancient kingdom of the Gonds.

Pangea is derived from the Ancient Greek pan meaning ‘all, entire, whole’, and Gaia – ‘Mother Earth, land’.

This name was coined by the German meteorologist Alfred Wegener. He developed the earlier theory of continental drift in 1912, which saw the Earth’s surface developing from great super-continent, the Urkontinent.

It was superseded by plate tectonics in the Sixties.

Peter Smith, Durham.

QUESTION In

comparison to man-made pollution, how does the Hawaiian volcano measure up?

EMISSIONS from volcanoes are dangerous at a local level. Carbon dioxide trapped in lowlying areas can be lethal to people and animals. Sulphur dioxide is irritating to the eyes, skin and respiratory system. Hydrogen sulphide is toxic in high concentrations while hydrogen halides can poison drinking water. Rather than warming the global climate, volcanic eruptions can have the opposite effect. Volcanic ash and microscopic particles reflect sunlight back into space, cooling the climate.

Dr Ian Smith, Cambridge.