Scientists trigger artificial quake on Japanese mountain

Researchers have triggered an artificial earthquake on a mountain in Japan in search of data to help find signs of possible volcanic eruptions.
Mount Zao is a 1,841-metres high complex volcano on the border between Yamagata Prefecture and Miyagi Prefecture in Japan.
It has become active since a magnitude-9.0 earthquake hit Japan in March 2011, with increased volcanic tremors.
A team from Tohoku University, together with Japan Meteorological Agency, detonated about 200 kilogrammes of dynamite inside a 40-metre-deep hole dug on the mountain side.
Water poured inside the hole spewed out with the force of the blast.
Seismic waves from the blast were measured by about 150 seismometers placed on the mountain, 'NHK World' reported.

Since seismic waves travel more slowly through water, analysis of seismometer data enables researchers to estimate pools and pathways of hot water up to about two kilometres underground.
Satoshi Miura, a Professor at Tohoku University, said finding out the locations of hot water is a key to guessing where the next steam-blast explosion could occur.