terça-feira, 28 de agosto de 2007

Capelinhos Volcano

Our Volcano

Between the 16th and the 27th September 1957, Faial island was shaken by about 200 earthquakes.

Their intensity never surpassed level 5 of the Mercalli Scale.

On the 27th of September, at 8:00am, the submarine eruption began offshore the western part of Faial, next to the Capelinhos islets.

At first, there was only boilling seawater but the activity started to increase and the jets of volcanic ash reached sometimes an altitude of 1000 metres.

In the afternoon of the 27th September, the volcano began furiously to eject scoriae, smoke and water vapour. The smoke and water vapour, quite thick, rise in the atmosphere, while scoriae are sent at heights of more than 400 metres. As result of the constant eruptions an islet was formed and named "Ilha Nova" (New Island) and "Ilha do Espirito Santo" (Holy Spirit Island).

As consequence of the explosions and accumulation of ashes, the locals began to leave their houses. The workers of the lighthouse had also to move away.

During the night of the 6th to the 7th October, the volcano registered one of the most intense moments. A violent fall of ashes damaged the cultivated land and originated the departure of the neighbour populations (1712 persons and 500 head of cattle).

Until the 29th October the eruption continued violently. On the 21st there was the biggest explosion, which was heard on the whole island.

On the 29th October there was mud rain around the lighthouse and by the end of the month the small islet began to vanish.

The eruptions returned in November, originating a new islet, the third that would connect itself to Faial by an isthmus. In December it reached a width of 600 metres and a height of 60 metres.

By the end of December and after the sinking of the cone, the submarine eruption restarted.

In March, Capelinhos islets had disappeared under the ashes. In the area of the lighthouse and in "Porto do Comprido" (small port) the thickness of the sand reached several meters burying the houses and causing the roofs to collapse.

In the beginning of May, the submarine eruption was decreasing. Nevertheless, after the 12th May, the earthquakes started again and were felt all over the island. About 460 earthquakes were registered between 6.00pm of the 12th May and noon of the 14th May. There were pauses of half a minute only. Afterwards there was a decrease until the end of June. The total of earthquakes was of 580.

Worth of note is that the earthquake in the night of the 12th to the 13th May 1958 destroyed totally the parishes of Praia do Norte and Ribeira do Cabo. Other neighbour areas were partially destroyed.

508 houses were destroyed, 504 families lost their homes, making a total of 1987 persons without a house.

One of the most fearful moments was when on the 14th May a small eruption occured in the "Caldeira", the central crater of the island. If it had continued it would have put at risk the security and integrity of Faial.

Fortunately, there were no serious consequences but evacuation plan of the island was ready to be executed.

From June until October 1958, the explosions continued with the emission of lava flows.

Finally after the 25th October 1958, Faial Island was back in peace.

One of the consequences of this eruption was an increase in the area of the island, which grew more than 2,4 km2, formed by ashes and lava.

Note: This summary was written with the help of the book O Ano do Vulcão (the year of the volcano) published in 1999 by Dr. Carlos Lobão.

Picture by Dr. Luis Decq Mota.

Translation by S.D.

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