Museum records largest earthquake in UK since 2008!
The British Geological Survey (BGS) reported a 4.1 magnitude earthquake in the Bristol Channel at 13:21 GMT on 20th February 2014. The event was also recorded on the Museum seismograph in the Evolution of Wales Gallery at National Museum Cardiff.
This is the largest earthquake in the UK since the 5.2 magnitude Market Rasen quake in February 2008.
The earthquake was felt widely across South Wales, Devon, Somerset and western Gloucestershire. Reports to the BGS described “felt like the vibration of a large vehicle passing the building”, “the whole house seemed to move/wobble back and forth a few times”.
The earthquake epicentre is estimated to be 18 km NNW of Ilfracombe at a depth of 3km.
Although the UK is not located on a plate margin, on average 200 – 300 earthquakes a year are recorded in Britain. Most earthquakes are so small they are not felt by people, and can only be picked up by the sensitivity of a seismometer.
The UK is located on the European plate. Tension is built up in the plate as new crust is created at the Mid Atlantic Ridge, and the plate is slowly pushed towards the north-east.
There are several long-active faults in the Bristol Channel which include the Bristol Channel – Bray fault. Once faults form, they create weak zones in the crust that can be reactivated time and time again. Movement occurred along one of these faults as tension in the crust was released.
On average an earthquakes of this size affects mainland Britain once every 2 years.
The largest recorded mainland event is the magnitude 5.4 earthquake on the Lleyn Peninsula in July 1984, where movement occurred along a long-active pre-existing fault.
Bwrw glaw yn sobor iawn...
On’d oedd mis Ionawr yn wlyb a gwyntog gyfeillion y gwanwyn? Dwi’n siŵr ei bod hi wedi bwrw bob dydd! Ond faint o law welson ni, o’i gymharu â’r cyfartaledd?
Mae Gwyddonwyr Tywydd y Swyddfa Dywydd wedi creu’r map yma o’r DU i ddangos faint o law a ddisgynnodd ym mis Ionawr. Gallwch chi gael golwg fanylach drwy ddilyn y ddolen.
Sut wnaethon nhw gyfrifo’r cyfartaledd glawiad? Mae Gwyddonwyr y Swyddfa Dywydd wedi bod yn cadw cofnodion tywydd am amser maith! Dyma nhw’n canfod cyfanswm y glawiad yn Ionawr am 30 mlynedd (rhwng 1981 a 2010) cyn rhannu â 30 i weld cyfartaledd blynyddol y glawiad.
Allwch chi weld y ddau liw glas tywyll? Disgynnodd rhwng dwy a thair gwaith yn fwy o law na’r cyfartaledd yn yr ardaloedd yma yn ystod mis Ionawr? Allwch chi weld yr ardaloedd du yn ne Lloegr a dwyrain yr Alban? Roedd y glawiad yn yr ardaloedd yma dros dair gwaith yn fwy na’r cyfartaledd yn ystod mis Ionawr!
Cyngor craff i ddefnyddio’r map:
- Mae 100% o’r cyfartaledd yn golygu ei bod hi wedi glawio yr un faint â’r cyfartaledd.
- Mae 200% o’r cyfartaledd yn golygu ei bod hi wedi glawio ddwywaith cymaint â’r cyfartaledd.
Allwch chi ganfod eich cartref ar y map? Beth yw lliw y map yn eich ardal chi? faint o law ddisgynnodd yn lleol? Oedd mwy neu llai o law na’r cyfartaledd? Efallai y gall eich athro eich helpu i ateb y cwestiynau yma!
Eich cwestiynau, fy atebion:
Gladestry C.I.W. School: Our school was closed on Thursday because of a power cut so our head teacher recorded the results that day. Prof P: We done to your head teacher! I am very glad your head teacher is helping you with your investigation.
St Mellons Church in Wales Primary School: Hello Professor Plant. It has been so windy this week that our thermometer has blown off the wall and broken. We have been using the car thermometer. L, J and L-b. Prof P: Hello L, J and L-b at St Mellons School! I am very sorry to hear that your thermometer is broken, I will email your teacher and arrange to send you a new one. Well done for your quick thinking in using the car thermometer.
Bleasdale CE Primary School: It is very cold and wet. Prof P: I agree Bleasdale School!
Ysgol Gynradd Dolgellau: Yn anffodus mae ein thermometr wedi torri ar ol cael ei chwythu gan y gwynt mawr yn ystod yr wythnos. Athro’r Ardd: Trueni mawr i glywed hyn Ysgol Gynradd Dolgellau. Bydda i’n e-bostio eich athro i drefnu anfon thermomedr newydd atoch chi.
Manor Road Primary School (Lancashire): on Wednesday there was a red weather warning but luckily the plants stayed in place. Prof P: I’m very happy to hear that your plants are okay!
Stanford in the Vale Primary School: It is very rainy here but we are not flooded. Prof P: I am very glad to hear that Stanford! What colour is the rainfall map is your area?
Burscough Bridge Methodist School: The heavy gales have caused the rainfall measurements to be unreadable as the measuring vessel was continually disrupted and blown over. Prof P: Gosh it must have been very stormy. Thanks for letting me know, keep up the good work!
Diolch yn fawr
Exploring Insect Diversity in Thailand
Work continues in a joint project with colleagues at the Entomology Section of the Queen Sirikit Botanic Garden (QSBGE) in Thailand exploring the diversity of tropical Diptera (flies). The objectives are to learn more about why two mountains in northern Thailand are such hotspots of diversity (the number and variety of species) and why so many endemic species are found there (an endemic species is one entirely confined to a particular locality). We should also learn much about the ecology of different communities of insects living in different forest types occurring at different altitudes. The project was started last January with Malaise traps (a tent-like structure into which insects fly and can be trapped) being set up along an altitude transect on Thailand’s highest mountain Doi Inthanon, and in the summit forests of slightly lower Doi Phahompok. Wichai Srisuka and his staff from QSBGE will empty the contents of the traps every two weeks for a full year and their team of expert technicians will conduct initial sorting and identifications at their laboratories and collection centre not far from the city of Chiang Mai. Some of the initial collections have already been made and many potentially very interesting specimens have been collected. The first consignment of material will be arriving in Cardiff shortly where I will begin the detailed taxonomic work; identifying species that have already been described, and, the more exciting part of recognizing and describing the many completely new species that will undoubtedly be found. I hope to feature some of the new species found in this blog later this year as the work progresses.
Dr Adrian Plant
Blodau cyntaf Cymru a Lloegr!
Newyddion gwych gyfeillion y gwanwyn, mae’r cofnodion blodau cyntaf wedi cyrraedd!
Ysgol Gynradd North Road, Carnforth yn Swydd Gaerhirfryn, oedd yr ysgol gyntaf i anfon eu cofnodion ata i. Agorodd eu crocws cyntaf ar 4 Chwefror.
Ysgol Gynradd Wirfoddol Reoledig Raglan yn sir Fynwy, oedd yr ysgol gyntaf yng Nghymru i anfon eu cofnodion blodau. Agorodd eu crocws cyntaf ar 7 Chwefror.
Da iawn i’r ddwy ysgol am anfon eu cofnodion ata i!
Mae Ysgol Gynradd yr Archesgob Hutton yn Lloegr hefyd wedi sylwi bod y crocysau a blanon nhw yn y ddaear yn dechrau tyfu. Bydd planhigion yn y ddaear yn aml yn blodeuo’n gynt na phlanhigion mewn potiau. Oes unrhyw un arall wedi sylwi ar hyn?
Mae’r cofnodion blodau wedi cyrraedd yn llawer cynt na’r llynedd. 1 Mawrth oedd dyddiad blodeuo cynharaf y crocysau y llynedd. Beth yw’r rheswm am hyn?
Wrth edrych ar ganlyniadau Project Bylbiau’r Gwanwyn dros y blynyddoedd, gallwn ni weld bod y dyddiadau blodeuo yn gynt gan fo glawiad yn uwch, y tymheredd yn uwch a mwy o oriau o heulwen. Meddyliwch pa dywydd ydych chi wedi ei brofi yn ddiweddar? Fydd y tywydd eleni yn helpu eich blodau i dyfu ys gwn i?
Eich cwestiynau, fy atebion:
Ysgol Terrig: Our bulbs are now growing above the soil. Prof P: Fantastic new Ysgol Terrig, hopefully it won’t be long until you start to see flowers.
Glyncollen Primary School: we are very exited because are bulbs are going to open soon. next week we are going to measure them. Prof P: Great investigating Glyncollen, have fun with your measuring.
Manor Road Primary School (Lancashire): It rained a lot and it was very cold and windy. It has not been minus yet. Prof P: I haven’t recorded a minus temperature in Cardiff either.
Stanford in the Vale Primary School: We have had alot of rain recently but the bulbs continue to grow bigger and bigger. Prof P: It certainly has been very very rainy, I hope you haven’t had any flooding.
Greyfriars RC Primary School: Me and D. are watering the plants really well. We enjoyed it alot. D: I am really enjoying the bulbs. My one is called xdox and pop. It was supposed to be xbox and pop. Thank you enjoyed this week. Prof P: What funny names for your plants! Very imaginative.
Freuchie Primary School: The children were really excited on Monday 27th January when they realised that 40mm of water had been collected over the weekend! Prof P: Wow - that really is a lot of rain!
Woodplumpton St. Anne's Primary School: We are very excited because the first shoots are beginning to appear. It has been very wet but so far the temperature has not dropped below zero. We wonder if this is unusual. Prof P: Great question Woodplumpton! I have had a look back over our weather data for previous years and it looks like this is not that unusual. The average daytime temperature for the month has only dropped below zero once in the 8 years we have been running the Spring Bulbs investigation. This was in December 2011 when there was heavy snow. I do think it has been less cold this January than in previous years. I look forward to receiving the weather data from all the schools so I can compare all the data in my Spring Bulbs Report!
Newport Primary School: Horrible wet weather most of the week. Prof P: The trouble with the rain is that it gets in the way of playtime doesn’t it?
Manor Road Primary School (Lancashire): The weather has been cold, wet and windy this week. We have spotted our first shoots peeping through in our pots though. Prof P: It seems like your bulbs don’t mind the wet weather too much.
Chatelherault Primary School: Bad news some people have been pulling out our bulbs but some are growing. And we have had a lot of rain and sun. Prof P: Oh no! I’m sorry to hear that someone has disturbed your bulbs. I hope that the ones that are left will be okay. Sun and rain are the perfect combination to make them grow!
Diolch yn fawr