A curious circumstance connected with the eruption of Mt. Pelée was the most pronounced electric and magnetic disturbances. Moreover, as in the case of the eruption of Krakatoa, there were the same after glows or red sunsets and sunrises due to the presence of fine volcanic dust in the higher regions of the air. These phenomena were observed over widely separated areas.
It appears that this great eruption in Martinique was preceded by severe earthquakes in the northern part of South America, especially in Colombia and Venezuela. The most marked was the great earthquake which on April 18th destroyed the city of Guatamaula; this was, perhaps, the most destructive earthquake that has occurred in the Western Hemisphere since the great earthquake of 1812, that destroyed the city of Caracas. Indeed, Professor Milne suggests that it was this earthquake that brought about the eruption of Mt. Pelée.
Soufrière, on the island of St. Vincent, had a great eruption on May 7th, 1902, one day before the awful eruption of Mt. Pelée. No lava flowed during this eruption. There were, however, great discharges of mud, due to a lake that before the eruption filled the top of a depression known as the old crater which lay southwest of a new crater, or the crater that was formed during the eruption of 1812. The old crater was nine-tenths of a mile across from east to west, and eight-tenths of a mile from north to south. The depth to the crater floor was from 1,000 to 2,400 feet. The surface of the new and shallow boiling lake which occupied the deepest part of the floor during the latter part of May, and from June to August, was estimated to be only 1,200 feet above the level of the sea. The sheet of water that occupied it before the eruption being several hundred feet higher.
Soufrière did not fail to give warnings of its coming eruption. Rumblings were heard two days before the explosion. On May 5th, 1902, fishermen who crossed the lake noticed that the water was disturbed and agitated. On the Tuesday following, May 6th, great clouds were thrown out during the afternoon, and the volcano was illumined by a reddish glare of fire. The first explosion was heard shortly before two o'clock on the following day and the volcano burst into activity. The explosions, together with great discharges of pumice, ashes, and boulders, followed one another rapidly. A column of steam was shot up into the air for a height of 30,000 feet. The severest paroxysm came shortly after ten a. m., and was succeeded by others nearly as violent during the next few hours. By this time a reddish curtain of clouds nearly shut out the island from view, and rapidly advanced over the land and descended on the sea. This eruption caused a loss of life of about 1,350.
This eruption of Mt. Soufrière was accompanied by the same tornadic blast of glowing air. There was not, however, any single blast quite as severe as that which attended the eruption of Pelée on May 8th, 1902.