Base isolation is one of the popular means of protecting a structure against earthquake ground shaking. This technique essentially isolates the overlying structure from the underlying substructure. The video below shows how triple friction pendulum bearings work compared to the standard single pendulum bearings.
The triple friction pendulum bearings are used to base isolate Sabiha Gökçen Airport’s new terminal in Istanbul. In simulation tests the structure is said to be able to withstand shaking from a magnitude 8 earthquake.
The British Geological Survey (BGS) has confirmed the recording of a magnitude 4.1 earthquake in the Bristol Channel at 13:21 on Tuesday 20th February.
Ground shaking from the earthquake was widely felt in north Devon and south Wales. Little damage is expected from an event of this magnitude and now injuries have yet been reported.
It is not unknown for parts of the British Isles to experience small to moderate size earthquakes. These are due to the sudden release of built-up stress on old fractures and faults in the ground.
The image above shows the seismograph recording of the the earthquake on the Hartland (HTL) seismic station.
A summary of the event is given below
Picture credit: BGS
The UK is battered once again as the latest storm strikes the west coast.
The Met Office has issued a rare Red Warning for west Wales and north-east England. Forecasters warn to prepare for hurricane force winds up to 100mph in some parts of the UK.
Please keep an eye on the Met Office and Environment Agency websites for the latest warning and weather reports.
The figure above is a satellite image of today’s storm.
This is an extraordinary animation of the Winter storms that have battered the UK over the past couple of months.
The current Winter is already the wettest on record and unfortunately there are no signs of the weather getting any better. At the time of writing there are 14 severe flood warnings in the southern UK with more rain expected today.
If you have been affected by the flooding please avoid walking in flood waters. Flooding can cause manhole covers to come off, leaving hidden dangers.
Ecuador’s Tungurahua volcano erupted 3 times last Saturday prompting the evacuation of local villages.
Ecuador’s Geophysics Institute reports that two moderate explosions on Saturday were followed by a third of greater size, and pyroclastic flow stretched 500 meters down its flank. The eruption created a 8 kilometre column of ash above the volcano, which is located 135 kilometres southeast of the capital, Quito.
Tungurahua is a 5023m high stratovolcano and is one of South America’s most active volcanoes. Since 2000, a new lava dome has been growing in its summit crater.
Mount Sinabung, located in northern part of the Indonesian island of Sumatra has been undergoing near constant eruptions since September last year.
A pyroclastic flow is a superheated (often with temperatures in excess of 500 degrees Celsius) dust and debris cloud that flows down the volcano. These can flow downhill at extraordinary speeds, often greater than 200km per hour.
Pyroclastic flows are the most destructive hazard from these type of volcanic eruptions. The video above shows one of Sinabung’s pyroclastic flows – made by Photovolcanica.
El Niño is a weather phenomenon that develops across the Pacific Ocean. Essentially it is a band of anomalously warm ocean water temperatures that develops off the west coast of South America.
El Niño causes climatic changes across the Pacific and can result in severe droughts on the western Pacific while the eastern Pacific experiences anomalously high rainfall and catastrophic floods.
These extreme weather events typically occur once every 20 years but a new study published in the journal Nature Climate Change suggests that extreme El Niño events could occur twice as often due to the effects of global warming.
The last such event occurred in 1997/98 in which the anomalous conditions caused widespread environmental disruption including the disappearance of much marine fauna in the Pacific. The impacts affected every continent and claimed an estimated 23,000 lives worldwide causing USD 35-45 billion in damage.