The Korea Meteorological Administration(KMA) is predicting that more aftershocks with a magnitude of three to four will likely continue in Gyeongju, North Gyeongsang Province for as much as several months.
Four-hundred-23 aftershocks have occurred in the region so far since it was hit with a five-point-eight-magnitude earthquake on September 12th.
The weather agency told a briefing Thursday that 90 percent of the aftershocks occurred within a two-point-five kilometer radius from the epicenter of the main shock, adding that their seismic centers are 15-point-two kilometers deep underground on average.
The KMA explained that 70 percent of the aftershocks were concentrated within two days after the main shock, as the earth’s crusts and faults twisted by powerful vibrations were returning to their original positions.
As part of efforts to reduce earthquake-incurred damage, the KMA will shorten the time needed for issuing early warnings of quakes with a magnitude of five-point-zero or above from the current 50 seconds to ten seconds by 2018.
In order to achieve the goal, it will increase the number of seismological observatories from the current 216 to 314 by the target year.