2007 Kent earthquake earthquake in 1950. The strongest recorded British earthquake is the 1931 Dogger Bank earthquake, which measured 6.1 on the Richter scale. Ten months later, the earthquake's strength was surpassed by that of the 2008 Lincolnshire earthquake, which was 5.2 in magnitude. Less than two years later, on 3 March 2009 at 14.35 UTC, Folkestone was shaken by a smaller magnitude 3.0 quake, located in the same area. 2007 Kent earthquake The 2007 Kent earthquake registered 4.3 on the Richter scale and struck south east Kent, South East England on 28 April 2007 at 07:18:12 UTC (08:18:12 local time), at a
Richter magnitude scale used by astronomers. Second, he wanted a magnitude of zero to be around the limit of human perceptibility. Third, he specified the Wood-Anderson seismograph as the standard instrument for producing seismograms. Magnitude was then defined as "the logarithm of the maximum trace amplitude, expressed in microns", measured at a distance of 100 km. The scale was calibrated by defining a magnitude 3 shock as one that produces (at a distance of 100 km) a maximum amplitude of 1 micron (1 µm, or 0.001 millimeters) on a seismogram recorded by a Wood-Anderson torsion seismograph. Finally, Richter calculated a table of distance