The volcanic activity will result in geological hazards which clearly depend on a variety of factors, for example the distance from the volcanic vents, population in area, volcanic eruption types and sizes. The main causes of the geological hazards (special human life) are pyroclastic flows, debris avalanches, tsunami and starvation during volcanic eruptions. The records of human life lost in eruptions prior to AD1600 is not enough sufficient. Then, the post-AD1600 records might be discussed. On this basis, number of deaths caused by direct and indirect volcanic eruptions was summarized in less 300,000 in last 400 years. Comparison with those by earthquakes in last 10 years (2001-2011), number of life lost is upper to 800,000 (USGS data), which is much higher than those by volcanic eruptions. However, if we consider the super-eruptions (VEI＞7) in geological time scale, they should effect the global climate changes. Our data showed that the bottle neck of human evolution probably related with the results of super-eruptions. The highly volcanic risk in Korea could be from dispersion of volcanic ash. The flights from Korea to northern America shall fly over the volcanic ash cloud in central and northern Japan. The civil aviation safety would be paid more attention.

• Chen, Chang-Hwa(Research Fellow and Deputy director, Institute of Earth Sciences Academia Sinica, Taiwan.)