On 18 November 1929 a tsunami struck Newfoundland's Burin Peninsula

'Grand Banks' Earthquake

At 5:02 p.m. on Monday 18 November 1929, an underwater earthquake occurred on the southern edge Grand Banks, about 265 kilometres south of Newfoundland's Burin Peninsula. It measured 7.2 on the Richter scale and was recorded in locations as far west as New York and Montreal and as far east as Portugal. On the Burin Peninsula, ground tremors lasted for about five minutes but did not cause any serious damage to houses or other structures. No one in the area had experienced an earthquake before, and although a few people understood what was happening, none imagined the tsunami that would follow.

On the Grand Banks, the earthquake triggered a sizeable underwater landslide, which in turn forced a series of large waves across the ocean's surface. The tsunami raced towards Newfoundland at speeds of up to 140 km/hr, before slowing to about 40 km/hr in shallower water. It registered on tide gauges in Bermuda, Portugal, the Azores, and along the United States' eastern coast. Newfoundland, however, had no knowledge of the giant waves that were quickly approaching its southern coast.

Tsunami Reaches Burin Peninsula

At about 7:30 p.m., residents along the Burin Peninsula noticed a rapid drop in sea level as the lowest point of the tsunami's first wave, known as a trough, reached the coast. As the water receded, it exposed portions of the ocean floor that were normally submerged and caused boats docked at various harbours to tumble over onto their sides. Minutes later, three successive waves hit the shore and water levels rose dramatically. In most places, the sea level swelled three to seven metres above normal, but in some of the peninsula's long narrow bays, such as at Port au Bras, St. Lawrence, and Taylor's Bay, the water rose by between 13 and 27 metres.

http://www.heritage.nf.ca/law/tsunami29.html