THE MOUNT PINATUBO ERUPTION 1991
the mount pinatubo eruption was the second largest eruption of this century and by far the largest eruption affecting a densely populated area. the eruption occurred at mount pinatubo in the philippines on june 15 1991. in march and april 1991 magma rising towards the surface from more than 30 km below pinatubo started making small earthquakes and caused small powerful steam explosion that opened three craters on the north flank of the volcano. thousands of small earthquakes occurred and many tons of gas were also emitted by the volcano. from june 7 to june 12 the magma reached the surface of mount pinatunbo. because of the gas pressure the magma erupted out with an amazing strength but did not cause an explosive eruption because it just formed a lava dome. on june 12 tons of gas charged magma reached the top of the volcano and erupted with the very first proper eruption. when even more magma reached the top the volcano erupted in a cataclysmic eruption on june 15. the eruption ejected more than 5 cubic kilometers of material. the ash cloud reached the height of 35 km in the sky. a blanket of ash covered all the land around pinatubo. fine ash flew thousands of kilometers away reaching also the inidian ocean. massive avalanches of hot ash rolled down the sides of pinatubo. the eruption removed so much material from the volcano that the volcano collapsed and from a clad era of 2.5 km. many hazards occurred with the volcano. the eruption produced high speed avalanches of hot gas and ash ( pyroclastic flows) giant mudflows (lahars) and a cloud of volcanic ash covering hundred of miles across. nearly 20 millions tons of sulfur dioxide were blown in the air and were dispersed around the world causing an increase in temperature of around 0.5 degrees.
Mt ST HELENS ERUPTION
mt st helens is a strata volcano located in the state of washinghton, US the eruption caused many hazards and