SEISMOMETERS belonging to the British Geological Survey in Herstmonceux detected the biggest earthquake to hit the south coast in 300 years which caused tremors in West Sussex.
The magnitude 3.9 earthquake happened in the middle of the English Channel just before 8am on July 13. Dr Graham Appleby, head of the NERC Space Geodesy Facility at Herstmonceux Castle, said: “The seismometer on the morning of July 13 2011 recorded the signal from the earthquake determined by BGS’ scientists to have occurred at a depth of 10km around 85km south of Portsmouth.”
Dr Appleby added: “The Natural Environment Research Council (NERC) Space Geodesy Facility (SGF) is based on the Herstmonceux Castle estate owned by the Bader International Study Centre.
“SGF is a facility that makes and analyses very accurate observations of the orbits of a wide range of Earth-orbiting satellites.
“These observations, made as part of an international network of such observatories, have a important impact on many topics of Earth-science research, including long-term monitoring of sea level change, dynamics of the polar ice-caps and the slow movement of the Earth’s continents that play a key role in mountain-building and which, of course, are also the cause of earthquakes.
“The facility also hosts in a basement an automated seismometer that is run by NERC’s British Geological Survey in Keyworth, Nottingham.
“The SGF site, located several miles from any major roads, is seismologically-quiet, and the instrument regularly records strong and weak events from around the world.”
The strongest event recorded in recent years was the devastating earthquake in Japan in February 2011, Dr Appleby said.
To find out more about the work of SGF visit: http://sgf.rgo.ac.uk