OR/18/015 Introduction

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Galloway, D D. 2018. Bulletin of British Earthquakes 2017. British Geological Survey. (OR/18/015).

The British Geological Survey's (BGS) Seismic Monitoring and Information Service operates a nationwide network of seismograph stations in the United Kingdom (UK). Earthquakes in the UK and coastal waters are detected within limits dependent on the distribution of seismograph stations. Location accuracy is improved in offshore areas through data exchange with neighbouring countries. This bulletin contains locations, magnitudes and phase data for all earthquakes detected and located by the BGS during 2017, listed in Table 1 and Table 2. Maps showing seismic activity in 2017 (Figure 1), and the larger magnitude events since 1979 (ML >2.5) and since 1970 (ML >3.5) are also included. The bulletin covers all of the UK land mass and its coastal waters including the North Sea (11°W to 6°E and 48°N to 64°N).

Figure 1    Epicentre map of earthquakes in 2017 as listed in Table 1.

All events believed to be of tectonic origin are included. Coalfield events are also included. Acoustic disturbances, such as sonic booms from supersonic aircraft, are included when they are felt. The airborne waves are readily identified by their slow travel time across an array but they are frequently mistaken as small earthquakes by the public. They are indicated by ‘SONIC’ in the locality column of Table 1. Significant non-natural events, such as explosions, which received media attention or were greater than magnitude 2.5 ML or felt by local residents, are also included in Table 1. Smaller events that are known, or suspected to be of explosive origin are excluded from the bulletin where possible. These include explosions due to quarrying, mining, weapon testing or disposal, naval exercises, geophysical prospecting and civil engineering. Unfortunately, identification by record character, location and time of occurrence is not always conclusive and some man-made events may be included in the bulletin or, more rarely, a small natural event may have been excluded.