Can’t stop shaking

 • An earthquake swarm is a series of seismic events of similar intensity striking a small area in quick succession.

• Greece’s Santorini and nearby islands have declared a state of emergency due to a swarm of undersea earthquakes.

• The frequency of earthquakes in the area has eased, but the outlook for continued tremors remains uncertain.

• The tremors are affecting magma, not the dormant volcano of Santorini.

• Swarms have been reported in peninsular India, where water seeps into small fractures in underground rocks after heavy rain.