South America earthquake caused tidal waves across the Pacific as far as Australia

SOMETHING strange was happening to the waters of Sydney Harbour 150 years ago. It was later found to have been caused by an earthquake in South America.

Fearful earthquake and tidal wave at Arica South America from the Illustrated Melbourne Post in 1868. Must Credit State Library of Victoria

SOMETHING weird was happening on Sydney Harbour in August 1868.

A report in The Empire newspaper described it as “an extraordinary tidal phenomenon … commencing during the ebb, about as near as can be ascertained, a little before 9 o’clock on Saturday morning.

“An excessive flow of the tide then took place, the extent of which may be gathered from the fact that it reached within a few feet of the foundation piers of the tollhouse on the Pyrmont Bridge, and ran out to a distance of 15ft from that point, in a less period of time than a quarter of an hour. This disturbance was witnessed at least four times in a period of two hours.”

The paper described boats being tossed around, a large amount of sediment being churned up, part of a sand spit being washed away at Middle Harbour and water appearing to “boil up”.

Nobody could remember seeing the waters of the harbour behave in such a way before. People speculated on possible causes.

Some blamed atmospheric disturbances, but the prevailing winds were blowing from the west, not coming in from the ocean. Some speculated on the possible effects of a coming solar eclipse or of a mysterious “submarine disturbance”, but others wondered if the waves could have been caused by an earthquake.

A photograph of the ruins of Arica after the earthquake of 1868.

News then began to filter through of tsunamis in Tasmania and New Zealand and soon it became apparent that an earthquake was the most likely suspect. Just such an earthquake had taken place across the other side of the Pacific in South America.

A tremor estimated to have been of a magnitude about 8.5 to 9 struck Peru and Chile 150 years ago today, on August 13, 1868. The worst hit was the port town of Arica in what was then Peru (now in Chile).

Arica had been inhabited by Native Americans for at least 10,000 years before the Spanish invaded in the 16th century. It was a place where overland trade routes met with a fishing village and where goods were exchanged for fish or taken further along the coast.

In 1541 Captain Lucas Martinez de Begazo began building wharves to convert the village into a port for Spanish ships. It became the main point of export for silver and gold mined in the region and was officially founded as the town of Arica in 1570.

The town was rich pickings for pirates; in 1579 Sir Francis Drake raided the town.

Arica remained an important entrepot into the early 19th century when Chile and Peru asserted their independence from Spain.

The Earthquake in Peru, Port Arica, from an authentic sketch published in the Illustrated Australian News in 1868. Picture: State Library of Victoria

In 1855 the Peruvians built a railway line connecting Arica to the inland city of Tacna. It became a major trade route. Goods were transported overland by pack mules to Tacna then sent by rail to Arica, loaded on ships to be taken around the world.

It was still a thriving port when it was rocked by a quake which centred offshore from Arica at a point where the Nazca Plate slides beneath the South American Plate.

The rumbling began at 5.15pm and some witnesses say it lasted for several minutes, by which time many buildings had been destroyed or badly damaged.

Twenty-five minutes later, after people decided it was safe to return indoors, an aftershock buried more in falling buildings. Survivors scurried back into the street and began heading for the hills.

About 50 minutes after the first quake, those residents who chose to remain were struck by a second, more deadly, disaster. Eyewitnesses say they saw the sea suddenly rush away leaving the ships in the harbour on a dry seabed. The waters then rushed back as huge waves, some as high as 16m.

USS Wateree, the Civil War gunboat beached and partially dismasted at Arica, Chile, after the tidal wave on August 13, 1868.

Ships that were capsized, swamped or dashed to pieces on rocks were carried inland. Civil War gunboat USS Wateree ended up 390m away from the shore, with the loss of just one seaman. They were more fortunate than their comrades aboard the Fredonia who all perished when the ship was destroyed.

About 25,000 people were killed or injured in the earthquake in Arica. But many other towns along the coast were also inundated by the tidal wave, and it is believed as many as 70,000 died.

The effects were felt all the way across the Pacific.

In New Zealand several people were killed trying to rescue a small boat when the ocean rushed out leaving the boat stranded on sand.

Back in Arica people tried to pick up the pieces. From their beached ship the crew of the Wateree dispensed aid to the Aricans. The ship was later deemed to be unsalvageable and sold and used as a hospital, an inn and a storehouse. Parts of the ship still remain there as a monument to tragedy.