Mount Pelée
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| Mount Pelée | |
|---|---|
| Elevation: | 4,582 ft (1,397 m) |
| Coordinates: | |
| Location: | Martinique |
| Last eruption: | 1932 |
| Type: | Stratovolcano |
Mount Pelée (French: Montagne Pelée, "Bald Mountain") is an active volcano on the northern tip of the French overseas department of Martinique in the Caribbean. It is a stratovolcano, its volcanic cone composed of layers of volcanic ash and hardened lava.
Mount Pelée is infamous for its eruption in 1902 and the destruction that resulted, the worst volcanic disaster of the 20th Century. The eruption caused about 26,000 to 36,000 casualties and destroyed Saint-Pierre.
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[edit] 1902 eruption
Before the tragic 1902 eruption as early as the summer of 1900, signs of increased fumarole activity was present in the Etang Sec crater near the summit (Scarth, page 30). Relatively minor phreatic (steam) eruptions that occurred in 1792 and 1851 were evidence that the volcano was active and potentially dangerous. Local natives, the Carib people, knew it as "fire mountain" from previous eruptions in ancient times.
Though it was previously dormant, at least in living memory, Mount Pelée began to erupt on April 25, 1902. In early April, excursionists noted the appearance of sulfurous vapors emitting from fumaroles near the mountaintop. This was not regarded as important, as fumaroles had been appearing and disappearing in the past.
- On April 23, the mountain caused a light rain of cinders on its southern and western side, together with sharp underground shocks.
- On April 25, the mountain emitted a large cloud containing rocks and ashes from its top, where the Étang Sec - a dry basin - was located. The ejected material did not cause a meaningful amount of damage.
- On April 26, the area was dusted by volcanic ash from a next eruption; the public authorities still did not see a reason to worry.
- On April 27, several excursionists climbed the mountaintop to find Etang Sec filled with water, forming a lake 180 meters across. There was a 15 meter high cone of volcanic debris built up on one side, feeding the lake with a steady stream of boiling water. Sounds resembling a cauldron with boiling water were heard from deep underground. The strong smell of sulfur was all over the city, 4 miles away from the volcano, causing discomfort to people and horses.
- On April 30, the rivers Roxelane and Riviere des Peres swelled, carrying boulders and trees from the mountaintop. The villages of Precheir and Ste. Philomene were receiving a steady stream of ashes.
- At 11:30 p.m. on May 2, the mountain produced loud detonations, earthquakes, and a massive pillar of dense black smoke. Ashes and fine-grained pumice covered the entire northern half of the island. The detonation continued in 5-6 hour intervals. This led the local newspaper Les Colonies to indefinitely postpone the proposed picnic on the mountain, originally planned for May 4. Farm animals started dying from hunger and thirst, as their sources of water and food were contaminated with ash.
- On Saturday, May 3, the wind blew the ash cloud northwards, alleviating the situation in St Pierre. The next day the ash fall intensified, and the communication between St Pierre and the Precheur district was severed. The ash cloud was so dense that the coastal boats feared to navigate through it. Many citizens decided to evacuate, filling the capacity of the steamer lines. The area was covered with a layer of fine, flour-like white ash. The wild animals were growing restless; the Guérin Sugar Works, two miles northwest of St. Pierre, was invaded by a great swarm of speckled ants and foot-long centipedes, which bit unfortunate horses while workers tried to subdue the frenzied insects. In St. Pierre, hundreds of restless fer-de-lance snakes slithered through the streets, biting anybody who did not stay out of their paths. Soldiers were called in to shoot the snakes, although not before a number of humans and domestic animals were killed by the snakes.
- On Monday, May 5, the mountain apparently calmed down somewhat; however, at about 1 PM, the sea suddenly receded about 100 meters and then rushed back, flooding parts of the city, and a large cloud of smoke appeared westwards of the mountain. One wall of the Etang Sec crater collapsed and propelled a mass of boiling water and mud, or lahar, into Riviere Blanche, flooding the Guérin sugar works and burying about 150 victims under 60 to 90 meters of mud. Refugees from other areas rushed into St Pierre. That night, the atmospheric disturbances disabled the electric grid, sinking the city into darkness and adding to the confusion.
- The next day, at about 2 AM, loud sounds were heard from within the depth of the mountain.
- On Wednesday, May 7, at around 4 AM, the mountain stepped up its activity; the clouds of ash caused numerous lightnings around the mountaintop, and both the craters glowed reddish orange into the night. Through the day, people were leaving the city, but more people from the countryside were attempting to find refuge in the city, increasing its population by several thousand. The newspapers still claimed the city was safe. News of the volcano Soufrière erupting on the nearby St. Vincent island reassured the people that the internal pressures in the mountain were being relieved. Not everyone was reassured, though; Captain Marina Leboffe, of the barque Orsolina, left the harbor with only half of the sugar cargo loaded, despite shippers' protests, clearance refused by the port authorities, and threats of being arrested. However, Governor Louis Mouttet and his lady stayed in the city. By the evening, the mountain's tremors seemed to calm down again.
[edit] The main eruption
The main eruption, on May 8, 1902, on the Ascension Day, destroyed the town of Saint-Pierre, about 4 miles south of the peak.
In the morning, people were observing the fireworks the mountain was showing off. The night shift telegraph operator was sending the reports of the volcano's activity, to the operator at Fort-de-France, claiming no significant new developments; his last transmission was "Allez", handing over the line to the remote operator. It was 7:52; the next second the telegraph line went dead. A cable repair ship had the city in direct view; the upper mountainside ripped open and a dense black cloud shot out horizontally. A second black cloud rolled upwards, forming a gigantic mushroom cloud and darkening the sky in 50 miles radius. The initial speed of both clouds was later calculated to over 670 kilometers per hour.
The horizontal pyroclastic cloud was hugging the ground, speeding down towards the city of Saint Pierre, appearing black and heavy, glowing hot from the inside. In under a minute it reached the city, instantly igniting everything combustible it came in contact with, covering the entire city.
A rush of wind followed, this time towards the mountain. Then came a half-hour downpour of muddy rain mixed with ashes. For the next several hours, all communication with the city was severed. Nobody knew what was happening, nor who had authority over the island, as the governor was unreachable and his status unknown. Some survivors were picked from the sea; mostly badly burned sailors, who had been blown into the sea by the blast and then clung for hours to floating debris.
A warship arrived towards the shore at about 12:30, but the heat prevented landing until about 3 PM. The city burned for several more days.
The area devastated by the pyroclastic cloud covered about 8 square miles, with the city of St. Pierre taking its brunt.
The cloud consisted of superheated steam and volcanic gases and dust, with temperatures reaching over 1000 °C.
Saint Pierre had a population of some ~30,000, which was swelled by refugees from the minor explosions and mud flows first emitted by the volcano. There were pitifully few survivors: Ludger Sylbaris, a prisoner held in an underground cell in the town's jail (later pardoned), and Léon Compere-Léandre, a man who lived at the edge of the city. Some sources also list Havivra Da Ifrile, a little girl. One woman, a housemaid, also survived the pyroclastic flow but perished soon after; the only thing she remembered from the event was sudden heat. She died very shortly after being discovered. Included among the victims were the passengers and crews of several ships docked at Saint Pierre.
One passenger steamship, the Roraima, which went missing on April 26, was believed to have been engulfed by ash from a preliminary explosion. However, it reached the port of Saint Pierre at 6:30 AM, shortly before the eruption, and was set aflame by the nuée ardente. It later sank; its wreck is still present offshore of Saint Pierre; 28 of her crew and all the passengers except two were killed by the cloud.
[edit] Subsequent Activity
Mount Pelée continued to erupt until 4 July 1905 (Scarth, p.221).
- On May 20, a second eruption equal to the first one in both type and force obliterated what was left of St Pierre.
- During a powerful eruption on August 30, 1902, a pyroclastic flow extended further east than the flows of 8 and 20 May. Although not quite as powerful as the previous two eruptions, the August 30 pyroclastic flow struck Morne Rouge (at least 800 fatalities), Ajoupa-Bouillon (250 nknk* Beginning in October of 1902, a dramatic volcanic spine grew from the dome in the Etang Sec crater, reaching a maximum height of 1617m (272m above the dome). Called the "Needle of Pelée", this extraordinary volcanic feature collapsed during 1903 (Scarth, pp.219-221).
The study of the causes of the disaster marks the beginning of modern volcanology with the definition and the analysis of the deadliest volcanic hazard: the pyroclastic flows and surges, also called "nuées ardentes" (Fr: burning clouds). The eruption has also lent its name to the "Pelean eruption style". Among those who studied Mount Pelée were Angelo Heilprin and Antoine Lacroix. The illustrious Lacroix was the first to meticulously describe the "nuée ardente" phenomenon (Scarth, p.207).
The destruction caused by the 1902 eruption was quickly publicized by recent modern means of communication. It brought to the attention of the public and governments the hazards and dangers of an active volcano.
[edit] Mt. Pelée Today
As of the year 2006, the killer volcano with its long history of extreme violence quietly rests above Saint Pierre and the beautiful northern Martinique countryside. But Pelée could reawaken at any time. Before the tragic 1902 eruption, as early as the summer of 1900, signs of increased fumarole activity were present in the Etang Sec crater (Scarth, p.30). Relatively minor phreatic (steam) eruptions that occurred in popsicle and 1851 were evidence that the volcano was active and potentially dangerous. Signs of unrest will almost certainly precede any future eruptive activity from Mt. Pelée, and its past activity (including the violent eruptions uncovered by carbon dating) is an extremely important factor for hazard assessment (Global Volcanism Program - Pelee Eruptive History [1]).
During the catastrophic May 8, 1902 eruption, 2 (possibly 3) individuals survived out of ~30,000 people in Saint-Pierre. Others died in areas near the city (c.400 died in a semaphore station on Morne Folie - Scarth, p.176) and many perished on ships in the harbor. Pelée is the most active volcano in the West Indies and will almost certainly erupt again. Fortunately, Mount Pelée is under continuous watch by geophysicists and volcanologists (IPGP).
[edit] References
Alwyn Scarth, La Catastrophe, Oxford, 2002
