In 17 55, we didn't have sysmometers. We don't know for sure what the magnitude was but thanks to those observations, we can get an idea. There are some suggestions that it might have been up to about eight point five. So a magnitude eight point five am along the west coast of europei is quite unusual. Earthquakes of that size, we kind of expect them. In places like chile, ind japan and sumatra, we get these very large earthquakes where we have a process called subduction. The general idea is that the bigger the fault, the bigger the earthquake you could have. And it's still a bit of a mystery as to where exactly
Melvyn Bragg and guests discuss the study of earthquakes. A massive earthquake in 1755 devastated Lisbon, and this disaster helped inspire a new science of seismology which intensified after San Francisco in 1906 and advanced even further with the need to monitor nuclear tests around the world from 1945 onwards. While we now know so much more about what lies beneath the surface of the Earth, and how rocks move and crack, it remains impossible to predict when earthquakes will happen. Thanks to seismology, though, we have a clearer idea of where earthquakes will happen and how to make some of them less hazardous to lives and homes.
With
Rebecca Bell
Senior lecturer in Geology and Geophysics at Imperial College London
Zoe Mildon
Lecturer in Earth Sciences and Future Leaders Fellow at the University of Plymouth
And
James Hammond
Reader in Geophysics at Birkbeck, University of London
Producer: Simon Tillotson