The magnitude 6.7 earthquake that struck southern Hokkaido last week came as yet another deadly reminder that a powerful temblor can strike at anytime and anywhere in this quake-prone country. The earthquake that caused large-scale landslides in the early hours of Sept. 6, burying around 40 victims — most of them in the town of Atsuma near Tomakomai — is believed to have been caused by the movement of an active fault that wasn't the one that was being monitored by the government's Coordinating Committee for Earthquake Prediction.

There are more than 2,000 known active faults on the Japanese archipelago, but, of course, the number of unknown faults is immeasurable. The magnitude 6.1 quake that hit northern Osaka Prefecture in June has been linked to a previously unknown active fault. Media reports highlighted the possibility that multiple hitherto unidentified active faults may lie in the area around Atsuma, close to the epicenter of where the temblor struck and registered the maximum 7 on the Japanese seismic intensity scale.

Currently it is impossible to forecast earthquakes immediately before they hit, and long-term forecasts of the probability of big quakes happening in certain areas may not serve as a reliable guide for risks since areas not deemed to be at a high risk for big temblors can still be hit by such disasters. We have to brace ourselves for the threats of unanticipated natural disasters and think of what precautions to take to minimize the damage they cause.