[2] The February 1964 event was a phenomenon related to a submarine volcanic eruption 6.5 kilometres (4.0 mi) west-northwest of the village of Velas, 1,000 metres (3,300 ft) below sea level.

[5] After 13 December, seismographs in the observatory in Horta registered earthquake swarms linked to a volcanic eruption that continued until January 1964, related initially with Capelinhos.

[5] The tremors reached a level VI (Strong) on the Mercalli intensity scale, causing panic and flight of citizenry to the town of Velas: the earthquake affected the areas of Urzelina, Manadas, Santo António and Norte Grande, intensifying until 18 February.

[5] On 21 February, between 5:14 p.m. and 5:25 p.m. three strong earthquakes destroyed the homes in Rosais, and caused damage to dwellings in Toledo, Serroa, Beira and the village of Velas.

[5] With lack of information, the constant tremors and poor weather conditions contributed to a general feeling of impending disaster among the citizenry.

[5] Logically, the earthquakes presupposed a submarine volcanic eruption; the smell of sulphur was observed on 18, 19 and 20 February in the town of Velas, and later in Rosais, Beira, Santo Amaro and Norte Grande, and carried on the wind toward the southwest.

[5] Meanwhile, a ship crossing the channel observed the presence of white caps on the surface of the water, indicating, possibly that there was a small eruption.

[5] Owing to the general panic and lack of help, 5,000 people were evacuated to the islands of Terceira, Pico and Faial, and were lodged in local homes, in an act of solidarity.

A majority of the evacuees were transported onboard international cargo containers, including specifically the English flag-carrier Remuera, which was travelling within the Azores at the time of the crisis.

Lack of planning and excavation equipment, meant that many of the peoples fleeing their homes, leaving the possessions and abandoning their domestic animals.

The Civil Governor, Teotónio Machado Pires (today remembered with a street named in his honour), visited the island and coordinated the relief operations.

By the late 20th century, there were still Quonset huts (metallic semi-circular huts/dwellings), invented for use in the Second World War, that were donated by the Americans to house many of those who had lost their homes.