Seismicity in the Vale of Pickering

The objective of our seismicity investigations is to monitor background seismic activity in the vicinity of the Kirby Misperton proposed exploration site and surrounding Vale of Pickering. The data collected will allow reliable characterisation of baseline levels of natural seismic activity and help discriminate between any natural seismicity and any future induced seismicity. A further aim is to make recommendations for a suitable traffic–light system to mitigate earthquake risk.

Design of the monitoring network

Ten seismometers have been installed at locations across the Vale of Pickering (Figure 1), six are surface seismometers and four have been installed in boreholes. Modelling indicates that this array of seismometers has a detection threshold of 0 magnitude events.

Data processing and analysis

Continuous real–time data from all installed stations are now being transmitted to the BGS offices in Edinburgh and has been incorporated in the data acquisition and processing work flows used for the permanent UK network of real–time seismic stations operated by BGS. A simple detection algorithm is applied to the data from the five installed stations as well as two permanent BGS monitoring stations in the region to detect possible events. All detections have been reviewed by an experienced analyst.

No events have been detected in the immediate locality of the Vale of Pickering. However, a number of other earthquakes and quarry blasts from elsewhere in the UK have been detected (the closest shown by yellow stars in Figure 1). As an example, the southernmost yellow star in Figure 1(a) shows the location of a magnitude 1.7 ML earthquake near Warsop, Nottinghamshire, in the relation to the monitoring network. Recordings of the ground motions for this event at the five stations in the network are shown in Figure 7(b) along with the recording at station HPK just north of Leeds. The signal–to–noise ratio is good and the event is well recorded, with clear P– and S–wave arrivals on most stations.


Figure 1. (a) Location of a magnitude 1.7 ML earthquake near Warsop, Notts. (b) Recordings of the ground motions for this event for the five stations in the network.



In addition, a number of large earthquakes from elsewhere around the world have been detected. For example, Figure 2 shows the recorded ground motions from a magnitude 7.5 earthquake in the Hindu Kush at 09:09 on 26/10/2015 at each of the five stations in the Vale of Pickering as well as the permanent BGS monitoring station GDLE. Numerous signals from various seismic waves that have propagated along different paths through the Earth are clearly visible, as marked by the dashed lines, suggesting that the data quality is good. Comparison with the permanent station GDLE suggests that the stations in the Vale of Pickering give a similar data quality to the permanent station.


Figure 2. Recorded ground motions from a magnitude 7.5 earthquake in the Hindu Kush at 09:09 on 26/10/2015, detected at stations in the Vale of Pickering and the.

In the future, processing will also include automatic detection and location of any seismic events along with an estimate of the event magnitude.

Data availability

Helicorder plots showing 24 hours of data from each station are available online and can be found on the BGS Seismology Team web site. These will shortly be moved to this web page and data portal. In the future, near real–time continuous seismic data (seismic traces) and processed event data will be made available through this website.


Contact

Contact BGS enquiries for further information.