BGS has worked with HR Wallingford and the Proudman Oceanographic Laboratory on a study commissioned by the Defra Flood Management Division to assess tsunami hazard for the UK and Irish coast.
The main objective of the study was to refine the potential impact of a repeat of the 1755 Lisbon earthquake and tsunami. Fault rupture parameters determined by BGS were used to calculate the vertical uplift of the seafloor for a number of possible scenarios, and provide an input for numerical modelling of the tsunami wave and its impact on the UK.
Modelling carried by HR Wallingford and POL gives maximum wave heights of 1-2 m around most of Cornwall, with 3-4 m identified between Penzance and Lizard Point.
UK Earthquake Monitoring
2005/2006
BGS Seismic Monitoring and Information
Service
Seventeenth Annual Report
Notes
BGSEarthquakeMonitoring-2006_17th_annual_report.pdf 2013-06-13 15:18 3.3M
BGS has worked with HR Wallingford and
the Proudman Oceanographic Laboratory
on a study commissioned by the Defra
Flood Management Division to assess
tsunami hazard for the UK and Irish coast.
The main objective of the study was to
refine the potential impact of a repeat of
the 1755 Lisbon earthquake and tsunami.
Fault rupture parameters determined by
BGS were used to calculate the vertical
uplift of the seafloor for a number of
possible scenarios, and provide an input
for numerical modelling of the tsunami
wave and its impact on the UK. Modelling
carried by HR Wallingford and POL gives
maximum wave heights of 1-2 m around
most of Cornwall, with 3-4 m identified
between Penzance and Lizard Point.
BGS seismograph stations, March 2006.
Detail of Cornwall Network
The spatial distribution of seismicity in
2005 generally reflects that observed in the
instrumental catalogue as a whole, with the
majority of earthquakes occurring in and
around Wales, Cornwall, the Midlands,
Cumbria and the Scottish Borders and in
western Scotland.
In the late 1960s BGS installed a network
of eight seismograph stations centred on
Edinburgh, with data transmitted to the
recording site in Edinburgh by radio, over
distances of up to 100 km. Data were
recorded on a slow running FM magnetic
tape system. Since then, the network has
grown in size, both in response to specific
events, such as the Lleyn Peninsula
earthquake in 1984, and as a result of
specific initiatives, such as monitoring
North Sea seismicity and the Hot Dry Rock
geothermal energy project in Cornwall.
UK Earthquake Monitoring 2005/2006
BGS Seismic Monitoring and Information Service
Seventeenth Annual Report
Extract via http://www.hayle.net/council/documents/BGSEarthquakeMonitoring-2006_17th_annual_report.pdf
THE SEISMICITY OF CORNWALL AND DEVON
R M W Musson
In the 36 years since ATJ Dollar presented his paper on the seismicity of the Cornubian Peninsula in relation to
structure, a great deal has changed in the understanding of British seismicity, both in terms of knowledge of its
distribution and parameters, and in terms of its geological and tectonic setting. This is as true for Cornwall and
Devon as for other parts of the UK. Since the late 1970s a large amount of effort has been directed into research
on historical earthquakes in the UK, undertaken with a critical approach to the appraisal of historical sources,
something previously lacking in studies of historical earthquakes. During the same period, modern instrumental
monitoring has been improved. The need for seismic monitoring of the geothermal energy project at
Rosemanowes [Rosemanowas] led to a dense local network capable of recording and locating even very small natural events.
In terms of average UK seismicity rates Cornwall and Devon are neither as seismic as the most active areas (such
as NW Wales) nor as quiet as the most inactive areas (such as NE England). While earthquakes in the area
occasionally cause public alarm, they seldom exceed 4 ML in magnitude and have caused very little damage in
the last 250 years.
The distribution of seismicity is irregular; most activity is concentrated in three zones: the
Penzance-Helston area; an area running from off the north coast of Cornwall, through eastern Cornwall to south
Devon, and the Barnstaple-Ilfracombe area. Relating this distribution to geological structure is a contentious
issue. Some major structures such as the Sticklepath Fault, (which has a reputation as being “active”
seismically) do not show up at all. It is likely that the distribution is influenced by the interaction of local
structures and reactivation along lines of old E-W thrust faults of Variscan age.
...
Most earthquakes in Cornwall are shallow (<7 km) probably due to high heat flow
11
associated with granite intrusions.
...
Table 1
Measured Ground Accelerations Recorded on Strong Motion Instruments in the UK
1994 - March 2001
Musson, R.M.W., 2000. The seismicity of Cornwall and Devon, Geoscience in South-West England, vol 10, pp 34-36.
http://earthquakes.bgs.ac.uk/publications/annual_reports/2001_12th_annu…