It was Mount Tambora, Indonesia. The eruption happened in 1815 and killed over 100,000 people. It was a gigantic explosion, which sent columns of flame 40 km high. About 200 million tons of sulfur dioxide and 50 cubic kilometers of lava came out into the crust. The island of Sumbaya, where the volcano is located, and sites 600 km away were left in darkness, shrouded in ash. A hurricane dragged houses out to sea, where tsunamis 5 meters high were formed. Many burned to death, but most were decimated by starvation and disease. Experts believe that, before this eruption, Tambora had been at rest for about 5,000 years.
They could be volcanic buildings or fissures in the crust. The volcanic edifice is formed by a high mound with a crater on top, like Etna, Vesuvius and Tambora itself. But most volcanoes are fissures in the crust, that is, large cracks in the ground through which lava flows, like the famous Kilauea in Hawaii
What defines an active volcano?
A volcano is considered active when it exhibits seismic activity and has erupted within the last 10,000 years. The potentially active one is the one that erupted within a period of 25 thousand years, has seismic activity, traces of magma and is geologically young. The inactive one does not show any signs of activity and has already undergone erosional transformations.
How do you prevent a major eruption?
The main active volcanoes are monitored by seismographs, which measure earthquakes; by GPS, which via satellite control the position of reference marks on the craters; and by chemical sensors, which assess the content and concentration of emitted gases. All this to capture signals that precede a major eruption, including the frequency and intensity of earthquakes, the appearance of cracks in the ground, and the emission of steam and volcanic gases such as CO2 (carbon dioxide) and H2S (hydrogen sulphide)
What’s in the smoke from volcanoes and what can it cause?
Basically ash and gases like CO2, SO2 (sulfur dioxide) and water vapour. Depending on the concentration, they can be harmful to health and the environment. SO2 causes acid rain and skin and nose irritation. In regions close to the volcano, the ash mixed with the hot air from the eruption can be fatal for the population, in addition to destroying crops and polluting the waters. Not to mention that they pollute the air and put the operation of planes at risk.
They are micro pieces of rock, the size of a grain of sand. Unlike ordinary ash, volcanic ash is abrasive and corrosive and does not dissolve in water.
Fumarole
Continuous ejections of water vapors and volcanic gases
gases
Eruptions give off water vapour, CO2 (carbon dioxide), N2 (nitrogen), SO2 (sulfur dioxide) and, to a lesser extent, H2S (hydrogen sulfide), hydrogen and HCl (hydrogen chloride)
Pyroclastic materials
Typical residue of large eruptions such as Tambora, mixing pulverized rock, lava and fragments from the volcano’s own crater
lahar
It is the mixture of pyroclastic materials, pieces of tree trunks and mud that forms shortly after an eruption.
Lava
It is the magma that comes to the surface, the rock in a molten state. It is usually released along with volcanic gases.
SOURCES – Umberto Cordani, professor at the Institute of Geosciences at USP; Philippine Institute of Volcanology and Seismology
Read too:
– How do volcanoes occur?
– Have there ever been volcanoes in Brazil?
– How did Vesuvius erupt?