Newdigate Earthquakes
Could recent earthquakes in Surrey be linked to oil and gas exploration? Surrey has previously been earthquake free, but the Newdigate area has had eight earthquakes since the beginning of April.
The exact location and depth of these earthquakes has not been determined, because the nearest monitors were too far away. This also makes it hard to determine the cause.
The British Geological Society (BGS) has just installed two new monitors in the quake area, so that now they will be able calculate location and depth of any future quakes.
In the USA, big increases in seismic activity have been recorded in places where waste fluids from oil and gas activities have been injected down old wells into deep rocks for permanent disposal. Over time, pressure can start to build up on geologic faults, causing them to slip. Earthquakes can occur miles away from the disposal wells and persist for more than a decade after injection stops.
Surrey and Sussex are heavily faulted. There has been some speculation in the press linking the recent earthquakes to the Horse Hill site, nine miles from Balcombe, where UKOG are preparing to flow test.
However, there is another oil site near the quakes, at Brockham, operated by Angus Energy, the new operator for the site in Balcombe.
FFBRA has learnt that Angus Energy have been transferring the waste from their oil well at Lidsey near Bognor to Brockham for disposal. In 2015 they put 690,922 gallons of waste into a well on the Brockham site. Angus have informed the Oil and Gas Authority that they injected waste into Brockham in March 2018. The first earthquake in the area occurred on 1st April 2018. FFBRA has submitted a FOI (Freedom of Information request) asking for details of how much waste has been injected in 2018.