Table 2. Time sequence of Shinmoedake Volcanic Alert Level.
Date | Volcanic Alert Level (Applied area) | Factors of level changes |
|---|---|---|
2007/12/1 | Level 1 | Strat of Volcanic Alert Level system in Japan |
2008/8/22 | Level 2 | Small phreatic event occurred. |
2008/10/29 | Level 1 | Volcanic activity became calm. |
2010/3/30 | Level 2 | Small phreatic event occurred. |
2010/4/16 | Level 1 | Volcanic activity became calm. |
2010/5/6 | Level 2 | Volcanic earthquakes increased. |
2011/1/26 | Level 3 (2 km) | Subplinian event occurred. |
2011/1/31 | Level 3 (3 km) | Vigorous growth of lava dome, increasing possibility of pyroclastic flow by its blowoff. |
2011/2/1 | Level 3 (4 km) | A vulcanian event occurred; ballistic bombs reached 3.2 km from the crater. |
2011/3/22 | Level 3 (3 km) | Frequency and magnitude of eruptive events became lower than those during January–February. |
2012/6/26 | Level 3 (2 km) | Seismic returned into the activity level before 2011. |