San Francisco is one of the most recognisable cities on the globe.
From its renowed Golden Gate Bridge and the Painted Ladies houses which have featured in the a number of TV shows and films, it is definitely one of the most promient locations in the United States.
While this incredible city welcomes well over 20 million visitors every year, there’s something that lies beneath the surface which many do not know about.
San Franscisco and the surrounding area is a hotspot for earthquakes and it is all because of its location.
The city, located on the west coast, sits right on the North American tectonic plate as well as the border of the Pacific plate. It is also divided by the San Andreas fault line.
San Francisco is part of a horsehoe-shaped reigon known as the Ring of Fire. Stretching around the Pacific Ocean for approximately 40,250 kilometres.
The Ring of Fire is where 90% of the world’s earthquakes happen and is home to 75% of all active volcanoes on Earth, reports National Geographic.
Whilst it is hard to prepare for unexpected events like earthquakes the United States is on a mission to do what they can to make San Francisco earthquake-proof.
Further down the west coast, the University of California, San Diego developped an Earthquake Simulator called the shake table.
The incredible piece of equipment which got a $17 million (£13 million) upgrade, can replicate the full 3D ground motions that take place during an earthquake and is capable of carrying and shaking structures up to 2000 metric tonnes.
In order to test the shake table, the Tallwood project was birthed. It was the tallest full-scale structure ever built and tested on the earthquake simulator, it’s also made from timber, reports the B1M.
Mass timber buildings which are constructed by bonding layers of wood together have become more popular in the US which is why the project is significant in the research carried out to defend San Francisco from future earthquakes.
Despite the city moving towards concrete construction in the 90s, there are still buildings with woodframes dotted around the city. They are known as soft-storey buildings and aren’t “shake-proof” which is why in 2013, a law that the buildings had to complete retrofits was passed.
Since then approximately 6,000 buildings have been revamp including the City Hall and the War Memorial Veterans Building. Now the process is taking place at one of the largest and busiest sites in the Bay Area – San Francisco Airport.
The refroiting project saw Harvey Milk Terminal 1 reopen last year after a rebuild that cost $2.5 million (just under £2 million) and the same thing is happening at Terminal 3 at a renovation cost of $2.6 million (approximately £2 million).
So although earthquakes may hit the city, residents can rest assured that San Francisco is becoming more prepared than ever before.
