Earthquake vibes measured on the Isle of Wight

Visitors to Carisbrooke Castle Museum may be surprised to learn that the building itself, and the Isle of Wight, was gently shaken by the massive earthquake in Russia on Tuesday, more than 7,500 miles away.

A seismograph trace, recorded by equipment housed in the museum, captured the Island’s subtle movements during the magnitude 8.8 earthquake. Although this global seismic event caused no damage here, the museum – and the ground beneath it – did imperceptibly move when the quake struck.

The seismometer responsible is located in the museum’s lower gallery, and is sensitive enough to detect earthquakes from across the world. The equipment is managed remotely by a museum volunteer, Graham Petrie, who monitors the seismic activity via the internet at home.

Carisbrooke Castle Museum, although situated inside the English Heritage site, is independently run. It was chosen to house the seismometer due to its strong links with Professor John Milne, a pioneering figure in earthquake science. Milne, often deemed the ‘Father of Modern Seismology’, lived at Shide Hill House, in Newport, and carried out scientific work in the castle grounds. He died on July 31, 1913, and is buried at St Paul’s Churchyard in Barton.

This recent recording of seismic activity highlights the ongoing legacy of Milne’s work, and the Isle of Wight’s small but fascinating role in the global study of earthquakes.

How do seismometers work?

Seismometers allow us to detect and measure earthquakes by converting vibrations due to seismic waves into electrical signals.
A seismometer has a heavy mass suspended by a spring or wire. This mass is designed to be relatively unaffected by the ground shaking.
As the ground moves during an earthquake, the seismometer’s frame and base shake, but the suspended mass tends to stay in its original position due to inertia – the principle that objects at rest stay at rest, and objects in motion remain in motion unless acted upon by an external force.