Letter: Forces of nature
Wednesday 15 September 1999
On this scale, last month's magnitude 7.8 earthquake in Turkey was big but not very special, as about 20 earthquakes between magnitude 7 and 8 on the Richter scale can be expected in any one year.
However, not all big earthquakes cause major damage, whereas some small earthquakes claim many lives. This depends on many factors, such as the depth of the initial rupture, whether the near-surface rocks magnify or dissipate the amplitude of the vibrations, and the quality of building construction.
Possibly of more relevance in news reporting of the scale of devastation caused by an earthquake would be the Mercalli scale. This ranks the intensity of the effects of an earthquake from I (detected by instruments only) to XII (total destruction).
On the Mercalli scale, last month's Turkish earthquake, and a Richter 5.8 earthquake that occurred in the same area on Monday, would both rank XI or XII in the centres of the most heavily damaged zones.
Dr DAVID A ROTHERY
Dept of Earth Sciences
The Open University
'At times I thought he was me'film
Review: One Direction, Fourmusic
Review: The World of Ice and Firebooks
Film More romcom than S&M
Review: The Imitation Gamefilm
Comedy...to show her mastectomy scars
TVNetflix gets cryptic
TV review A moving film showing kids too busy to enjoy their youth
Books Not even a Man Booker prize could save Richard Flanagan from a nomination
Arts & Ents blogs
- 1 To help fuel their propaganda machine against the poor, our government has now decided to redefine the word 'welfare'
- 2 Tower Bridge glass walkway 'smashed' by night-time visitor dropping bottle of beer
- 3 Anti-gay hate preacher accidentally tweets 4,000 followers cartoon clip of him 'confessing' to be a 'homosexual sodomite'
- 4 Woman opens professional cuddling shop – gets 10,000 customers in first week
- 5 Grayson Perry: London needs affordable housing because 'rich people don't create culture'
Christmas 2014: The three most intriguing celebrity panto appearances
Lee Evans announces his retirement from comedy on The Jonathan Ross Show
Saturday Night Live vs The Daily Show: US channels wage comedy star wars
Iggy Azalea responds to Eminem rape lyrics: 'I'm bored of old men threatening young women'
Beyonce '7/11' music video: Star bounces on bed and films daughter Blue Ivy in lo-fi homage to viral video
Rochester by-election: Ukip gains second MP as Tory defector Mark Reckless holds seat
'Beast of Bolsover' Dennis Skinner takes Ukip MP Mark Reckless to task moments after he is sworn in
Rochester by-election: Labour MP Emily Thornberry resigns after posting white van and England flags tweet
France 'blocks' Russian sailors from boarding a warship
Revealed: How the world gets rich – from privatising British public services
Myleene Klass: Ed Miliband 'strikes back' by comparing UK's need for Labour's mansion tax to Hear'Say track