What are the characteristics of the eruption of Mount Pere?

Mount Pere is located in the northern part of Martinique, West Indies in the East Caribbean Sea, with an altitude of 1 0,350 meters, which is the highest peak in the whole island. Named after the bare lava at the top. One of the most active volcanoes in the eastern Caribbean islands. 1792, 185 1 year has small-scale eruption. 1902 On May 8, a violent eruption destroyed the whole city of Saint Pierre, 6 kilometers south of it. The eruption covered one-sixth of the island, and almost all 30,000 residents in the city were killed. On August 30th of the same year, the eruption continued and two villages and towns were destroyed. There is still slight activity during 1929 ~ 1932. The hillside is gentle, the forest is dense, and the soil at the foot of the mountain is fertile. The city of Saint Pierre is about 6 kilometers away from the volcano. Mount Pere is a typical dome volcano with a history of 300,000 years. It is a layered volcano composed of intermediate-acid lava and pyroclastic rocks.

Unlike most volcanoes, Pei Lei is called a "flame thrower" because its top is bare lava, and its nozzle extends horizontally, not upward or inclined. In the explosion of 1902, hot lava flew out with the flame level. Spray it to the south at a speed of 290 kilometers per hour. Everywhere, forests turned to ashes, rocks turned to flour, houses became ruins, the sea boiled and everything was gone.

Why is Mount Pere uniquely sprayed horizontally? It turns out that the neck passage of Peilei Mountain is in a horizontal state, and at the same time, its lava has great viscosity, which tightly plugs the neck of the volcano like a big cork. It takes a lot of strength to break through it. Due to the continuous activity and accumulation of magma in the crust, the pressure is increasing, and the "cork" is washed away, forming a horizontal explosion. When a large amount of gas and volcanic ash are ejected, the underground pressure gradually weakens, viscous lava quickly blocks the passage, and underground lava is sealed.

1902 Pei Lei volcano eruption was the one with the largest number of deaths and the most disastrous one in the world.

Mount Pere is an active volcano, which erupted once in 1753, when Saint Pierre took shape at the southern foot of the city. Since then, fireworks have been set off intermittently, which has not brought any disaster to residents and added unusual scenery to the city. Every holiday, citizens will always go along the sulfur-filled crater to see the smoke screen, have a picnic on the hillside and take a bath in the hot spring.

From February 1902, this volcano woke up from more than 50 years of "deep sleep" and began to move. The residents of Saint Pierre discovered a series of miracles: silverware turned black, animals were restless, cows chirped at night, birds flew out of the forest of Mount Pere, wild animals fled, snakes moved, and some animals died inexplicably. It turns out that sulfur-containing gas is added to the air, and when silver meets sulfur, it changes chemically and becomes black silver sulfide. This is an alarm that the volcano is about to erupt, but the citizens who have lived in harmony with Peilei Mountain all their lives have not taken it to heart.

1902 On April 23, a column of black smoke emerged from the top of the volcano, and the explosion roared like thunder, and volcanic ash poured down, covering the streets and roofs with a thin layer. This surprised the residents greatly. The more dust is sprayed, the more it floats to St. Pierre, five miles from the crater of Pere. Residents are hiding at home, and schools and shops are closed. After several days of tossing, the volcano stopped all activities again. People breathed a sigh of relief

A few days later, the lake on the top of the mountain boiled and hissed because of geothermal energy, and a lot of water vapor evaporated. It turned out that it flowed down from the mountain, crossed the calm stream of Saint Pierre and became a boiling river. At that time, a very thick lava spire appeared from the top of Pere Mountain. It reached a height of 200 meters before it collapsed. If it hadn't collapsed three times in a row, its height would have reached 850 meters!

In the last days of Saint Pierre's existence as a city, the letters sent to America revealed a terrible atmosphere of terror, bad luck and impending death. Some people describe Saint Pierre as "a city full of gray snow, like winter but not cold". Residents fell into panic, and some people abandoned their homes and fled. Many people don't know what bad luck awaits them, whether it is a lava flow, a stone rain or a disaster from the sea. Did you burn to death or suffocate? The tragedy in Saint Pierre is mainly caused by stupid and wrong decisions. Because as early as a month before the volcanic eruption, people have found a very obvious precursor:

On April 2, Peilei Mountain began to spew a lot of hydrogen sulfide gas; 1902 On April 23rd, Pei Lei spewed dust, and the sky was dark and dusty at noon for several days. On May 2, the volcano erupted violently again, spewing a lot of lava and mud from the cracks on the jagged edge and falling into the nearby river, which boiled. Lava flow engulfed a sugar factory about 3 kilometers away from the city, and the factory building and 150 workers disappeared without a trace in the high temperature. When lava flows into the sea, it hisses and turns into steam. Less than 50 meters away from the land, the beach reached the bottom. In a blink of an eye, huge waves rolled in, flapping the coast and engulfing many fishing boats. On April 27, the volcanic lake at the top of the volcano kept emitting hot air; On May 4, thunderous explosions came from the top of the mountain from time to time; On May 5, several craters appeared on the hillside of Peilei Mountain, spewing out dust and stones, mud and magma flowed out of the crater, and the thick sulfur smell enveloped the city of Saint Pierre. On May 6, the volcanic ash from the volcano surged and landed in the surrounding area. Smoke hung over the town and the sky was dark. ...