Capelinhos Eruption: Natural Phenomena

The eruption of an offshore volcano near Capelinhos, the western cape of Faial Island in the nine-island Azores archipelago in 1957 came to be a defining moment in the history of Portuguese emigration. Villages on the northern and western coasts were devastated by the volcano's eruption, which led to the emigration of 4,000 people to the United States.

On September 27, 1957, whaling pilot João Faria thought that the disturbed waters off the islets of Capelinhos was a school of whales. The "vigia" (whale lookout) had signaled with his "foguete" (flare) that whales had been sighted. If only it had been whales that he had spotted...

Years: 1957 — 1958

The Eruption

The eruption started at 8 o’clock in the morning on September 27, 1957. At first, the eruption was in the form of a submarine eruption with the emission of water vapor and other gases. Also, as with other submarine eruptions, it was almost silent with only the sound of the roiling waters.

The volcanic activity quickly gained strength and soon the vents were ejecting large amounts of pyroclastic material. Water entering the submarine chimneys contributed to the explosive power of the volcano. Violent eruptions continued until October 29. This early activity created a small island 800 meters (2,400 feet) in diameter and 99 meters (300 feet) high. Some of the ejected material reached 1,400 meters (4,200 feet) into the sky. The small island that had formed submerged during a brief spell of inactivity, but quickly formed again when the eruptions resumed in November.

On November 12, the newly-formed island was attached to Faial when debris from the eruptions formed an isthmus. As 1958 began, explosions occurred on and off for months. On March 19, 1958, the explosive cloud rose more then 1,800 meters into the sky -- more than a mile. The falling ash covered much of the nearby villages of Capelo and Norte Pequeno. Also, the famous lighthouse at Capelinhos began to be buried in ash. From February 9-10, nearly 1.55 meters (5 feet) was deposited; on March 23, another 1.9 meters (6 feet) coated the landscape. At this time, large amounts of lava began to pour from the volcano.

Earthquakes

May 12, 1958, became known as the “night the earth shook”. That night, 450 earthquakes spread terror among the people of Faial. The number and intensity of these quakes convinced many that they would not survive the night and indeed that the entire island of Faial was in jeopardy and may suffer the fate of Pelee or Krakatoa--cataclysmic eruptions in the Caribbean and Indonesia that killed thousands. The tremors also caused vents to open up in the main caldera of Faial. May 14 saw dramatic flows of lava spewing from the volcanic vents--a lake of molten lava was created.

These events were part of the Strombolian phase of the eruptions. Strombolian eruptions are like those of Vesuvius, spectacular displays of lava and ejected material accompanied by tremendous noise. Some of the sonic booms were heard on Flores Island, 220 kilometers (120 miles) away.

Images (click on image to view full size)

Narration

<< BACK TO HISTORY & EVENTS