What are earthquake swarms – and is Australia at risk?

Powerful events can occur at any point during an earthquake swarm, unlike a typical earthquake where tremors trail off after the main shock. Photograph: olga Yastremska/Alamy

Birds do it, bees do it, and now geoscientists say even earthquakes do it.

An “earthquake swarm” has hit the Hunter region of New South Wales, with more than 30 seismic events recorded, according to Geoscience Australia.