The last catastrophic explosion occurred earlier when the year 1979 by spraying more than 200000 tons of ashes and then have another middle-level bomb 2 times in March 2007, and in May 1991.
The explosion severely last earlier years 1979 by spraying ash, released over the 200 000 tons. Then there was an explosion level again 2 times in March 2007 and May 1991 .