Fracking could shake the Conservative vote | Letter

Tremors above magnitude 3 could be destructive - not least to the Tory party if people's houses start crumbling, writes David Nowell

Having been taught seismology by Prof Peter Styles, who developed a traffic-light monitoring system in the 1980s that dramatically reduced the impact of coal mining under Swansea for local residents, I believe Jacob Rees-Mogg has a risible scientific understanding about shale gas extraction (Tory MPs angrily challenge Rees-Mogg's fracking revival plan, 22 September). Vibrations from quarries and building sites tend not to be widespread, compared to shaking generated a few kilometres beneath an area.

The current 05 magnitude limit was set so tremors should not rise above 25, because of the increased risk of larger magnitude events", according to a recent British Geological Survey report. Proposing a higher limit would be reckless, as any anthropogenic tremors above 3 could prove to be destructive - not least to the Tory vote, if people's houses start crumbling.