1990 Bishop's Castle earthquake

Earthquake in England April 2023 June 2013 Bishop's Castle earthquake 02 April 1990 2 April 1990 14:46 BST 1990-04-02 13:46 usp00047ck 371099 England#United Kingdom#Wales 5.1 ML 14.1 km on 52.43 N 3.03 W inline,title United Kingdom VIVI None en-UK The 1990 Bishop's Castle earthquake occurred near the town of Bishop's Castle, Shropshire, England on 2 April. Location, date and time On 2 April 1990, a powerful earth tremor was felt across much of England and Wales at 13:46 34.2s GMT. Early news reports in the immediate aftermath speculatively attributed the epicentre to places as far apart as Nottingham and a valley in the east of Wales and then settled on Wrexham,New Scientist Contemporary account of limitations to the original seismological reporting, which rates the earthquake at 5.4 on the Richter scale https://www.newscientist.com/article/mg12617120.400-how-britains-seismometers-got-it-wrong-.html 2008-02-02 before geologists finally concluded that it had in fact been in the vicinity of the small town of Clun near the town of Bishop's Castle, Shropshire.BGS Bishop's Castle page British Geological Survey http://www.quakes.bgs.ac.uk/macroseismics/bishopscastle_macro.htm 2008-02-02 dead https://web.archive.org/web/20070613063102/http://www.quakes.bgs.ac.uk/macroseismics/bishopscastle_macro.htm 13 June 2007 Cause Bishops Castle lies atop an ancient geological fault line – the Pontesford-Linley fault. A sudden movement in the fault sent shock waves through the rock.Shropshire County Council Landscape of contrasts http://www.shropshire.gov.uk/discover.nsf/open/81F8010DA4FE7DCC80256D6B005664A7 2008-02-02 https://web.archive.org/web/20070520154038/http://www.shropshire.gov.uk/discover.nsf/open/81F8010DA4FE7DCC80256D6B005664A7 20 May 2007 dead The local rocks are predominantly Jurassic Middle Lias.Shropshire Rocks http://www.shropshirerocks.org/shropshiregeologicaltrail 2008-02-02 https://web.archive.org/web/20081119145001/http://www.shropshirerocks.org/shropshiregeologicaltrail 19 November 2008 dead Magnitude The magnitude of the earthquake was originally measured as being between 4.9 and 5.4 on the Richter scale.New Scientist Another contemporary account from the same issue of New Scientist, 12 April 1990, but rating the magnitude at only 4.9 https://www.newscientist.com/article/mg12617120.100-a-case-of-the-shakes-.html 2008-02-02EERI Contemporary newsletter of the Earthquake Engineering Research Unit, April 1990 http://www.eeri.org/lfe/pdf/uk_bishops_castle_1990_newsletter.pdf 3 February 2008 Its final estimated magnitude was 5.1,BGS Bishop's Castle page Recent British Geological Survey page on the Bishop's Castle earthquake http://www.earthquakes.bgs.ac.uk/macroseismics/bishopscastle_macro.htm 3 February 2008 https://web.archive.org/web/20080116051050/http://www.earthquakes.bgs.ac.uk/macroseismics/bishopscastle_macro.htm 16 January 2008 dead which meant that it was the strongest earthquake to have struck the UK since the 1984 Llŷn Peninsula earthquake. Impact The earthquake was felt by people as far away as the east of the Republic of Ireland to the west, the city of Newcastle upon Tyne to the north-east, the county of Kent to the south-east, and the county of Cornwall to the south-west. In Shrewsbury, the county town of Shropshire, which lies approximately 20 miles to the north-east of Bishop's Castle, there was damage to masonry, with a number of chimney stacks being broken off from roofs and collapsing partially or completely into gardens and streets. Some others were knocked askew. Several of the worst affected buildings, including shops, were evacuated. Police cordons were put up around houses at risk of chimney-collapse until they had been made safe, with at least fifty properties in the town reported as requiring emergency attention within the twenty-four hours immediately following the event, while others requiring less urgent treatment were tended to on subsequent days.EERI Contemporary newsletter of the Earthquake Engineering Research Institute, April 1990 http://www.eeri.org/lfe/pdf/uk_bishops_castle_1990_newsletter.pdf 3 February 2008 There was also damage to ornamental features such as crosses and gargoyles built into the masonry of some of Shrewsbury's medieval churches, and to Clun Castle. Electrical power was lost from areas served by some substations situated approximately thirty kilometres (seventeen miles) from the epicentre after the earthquake caused transformers at the substations to trip offline. Residents of the worst affected areas, including parts of Shrewsbury, reported lateral shaking and swaying to the walls of their houses at the height of the tremor, which was preceded and then accompanied by a rumbling noise that gained strength over a period of 15 to 30 seconds before reaching and sustaining peak intensity during the most severe shaking. Finally, the movement and accompanying sound tailed off much more rapidly than it had first built up, stopping altogether within just a few seconds from the peak activity.Earthquake, Blast and Impact: Measurement and effects of vibration papers presented at the International Conference on Earthquake, Blast and Impact held at the University of Manchester Institute of Science and Technology, UK, 18–20 September 1991, graph 22 August 1991 Taylor & Francis https://books.google.com/books?id=dxtbhw-UE7AC&pg=PA5 978-1-85166-705-5Earthquake, Blast and Impact: Measurement and effects of vibration papers presented at the International Conference on Earthquake, Blast and Impact held at the University of Manchester Institute of Science and Technology, UK, 18–20 September 1991, discussion 22 August 1991 Taylor & Francis https://books.google.com/books?id=dxtbhw-UE7AC&pg=RA1-PA1 978-1-85166-705-5 Damage to buildings was also reported in Wrexham, and some minor damage as far north as Liverpool and Manchester.USGS Significant earthquakes of the world 1990 – see first April entry reporting geographical extent of masonry damage https://earthquake.usgs.gov/eqcenter/eqarchives/significant/sig_1990.php 2008-02-02 https://web.archive.org/web/20080212052356/http://earthquake.usgs.gov/eqcenter/eqarchives/significant/sig_1990.php 12 February 2008 live No serious injuries were reported. An engineering consultant, using the 1990 Bishop's Castle earthquake specifications as a model, has estimated that the slightly weaker 2002 Dudley earthquake measuring 4.8 on the Richter scale would have caused structural damage of an order costing less than 5% of the cost of the complete reconstruction of an entire property to repair, to 1% of buildings situated in towns in the vicinity of the epicentre.Will Re Civil Engineers Catastrophe Report http://www.willisre.com/html/reports/catastrophe/DUDLEY.pdf 2008-02-02 https://web.archive.org/web/20061109093215/http://www.willisre.com/html/reports/catastrophe/DUDLEY.pdf 9 November 2006 dead While some indication of the typical percentage of homes damaged to a similarly minor extent by a slightly stronger earthquake measuring 5.1 on the Richter scale may be extrapolated from this estimation, a representative of the British Geological Survey has stated that 'numerous' but fewer than 20% of properties in Shrewsbury suffered the partial or total loss of their chimneys or damage of equivalent gravity (see below). Reliable, exact figures of the percentage of buildings damaged close to the epicentre of the 1990 Bishop's Castle earthquake are not readily available, but the aforesaid sources taken together appear clearly to indicate that between 1% and 20% of properties in towns near the epicentre suffered damage of European Macroseismic Scale Grade 7 severity. The Welsh Borders suffer frequent earthquakes by British standards. Over the last century, there have been sizeable shocks near Hereford in 1896 and 1924, near Shrewsbury in 1932, and near Ludlow in 1926.New Scientist Magazine Ancient faults and modern earthquakes https://www.newscientist.com/article/mg12717244.000-ancient-faults-and-modern-earthquakes-britains-recentearthquake-happened-on-a-fault-that-was-active-hundreds-of-millions-of-yearsago--faults-of-similarly-ancient-lineage-could-be-the-sites-of-futuretremors-.html 2008-02-02 See also List of earthquakes in 1990 List of earthquakes in the British Isles References 1990 Bishops Bish Bishops Bishops Category:20th century in Shropshire Category:April 1990 in the United Kingdom Category:1990 disestablishments in the United Kingdom