In the quiet Vasse district of WA, the evening of 27 August 1883 must have felt like something out of a mystery novel.

Sergeant McDonald of the Vasse Police Station received a report from Constable Tonkin. Tonkin claimed to have heard the deep boom of “a large gun” coming from the northwest multiple times throughout the afternoon. Yet there was no ship in sight and no explanation.

The methodical and thorough sergeant launched an investigation. But the source of the sound was as elusive as it was unsettling. What the police were unaware of was they weren’t dealing with a local oddity but a global event.

The police report documents the baffling events. Along with Tonkin, several other residents reported hearing the sounds, which seemed to echo from the direction of the ocean.

Seeking answers, Sergeant McDonald dispatched PC Sutton to Cape Naturaliste the following day. Armed with a spyglass, Sutton scanned the waters for signs of shipping or distress.

Sutton returned 2 days later with no news. He hadn’t seen any ships, wreckage or activity around the Naturaliste Reef, which he confirmed was clearly visible through the spyglass.

Sutton did note one unusual phenomenon though. The tides at Cape Naturaliste had experienced a dramatic rise and fall over the past few days. He speculated these tidal movements could explain the mysterious sounds, but the sergeant’s report noted there had been no such changes observed at Vasse.

Without further clues, the investigation reached a dead end. The “gunfire” that startled the people of Vasse remained an enigma – until modern science shed light on the mystery.

Halfway across the world in Indonesia on the same date, the Krakatoa volcano erupted with such immense force, it shattered the island and sent shockwaves racing around the globe.