News from British and Canadian Conservatives

Sunday, May 06, 2007

Earthquake was Britain's most intense in a century

The British Geological Survey has written to me today stating that the Folkestone Earthquake of 28th April had an intensity of 8 EMS (European Macroseismic Scale), although it could be downgraded to 7 EMS when they complete their analysis. They state that it was "the highest recorded intensity for a British earthquake in over 100 years".

Wikipedia describes how the EMS is different from the Richter Scale. Apparently, the EMS records how strongly an earthquake is felt in a specific place, whereas the Richter Scale registers the magnitude of the energy released by the earth tremor.

The levels are described as follows:

1. Not felt: Not felt, even under the most favorable circumstances.
2. Scarcely felt: Vibration is felt only by individual people at rest in houses,
especially on upper floors of buildings.
3. Weak: The vibration is weak and is felt indoors by a few people. People at rest
feel a swaying or light trembling.
4. Largely observed: The earthquake is felt indoors by many people, outdoors by very
few. A few people are awakened. The level of vibration is not frightening.
Windows, doors and dishes rattle. Hanging objects swing.
5. Strong: The earthquake is felt indoors by most, outdoors by few. Many sleeping
people awake. A few run outdoors. Buildings tremble throughout. Hanging objects
swing considerably. China and glasses clatter together. The vibration is strong.
Topheavy objects topple over. Doors and windows swing open or shut.
6. Slightly damaging: Felt by most indoors and by many outdoors. Many people in
buildings are frightened and run outdoors. Small objects fall. Slight damage to
many ordinary buildings; for example, fine cracks in plaster and small pieces of
plaster fall.
7. Damaging: Most people are frightened and run outdoors. Furniture is shifted and
objects fall from shelves in large numbers. Many ordinary buildings suffer
moderate damage: small cracks in walls; partial collapse of chimneys.
8. Heavily damaging: Furniture may be overturned. Many ordinary buildings suffer
damage: chimneys fall; large cracks appear in walls and a few buildings may
partially collapse.
9. Destructive: Monuments and columns fall or are twisted. Many ordinary buildings
partially collapse and a few collapse completely.
10. Very destructive: Many ordinary buildings collapse.
11. Devastating: Most ordinary buildings collapse.
12. Completely devastating: Practically all structures above and below ground are heavily damaged or destroyed

More information about the earthquake is now on the British Geological Survey's website.

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