The Yomiuri ShimbunJapan is an archipelago frequently afflicted by disasters and surrounded by the sea. The nation must remain alert to the risk of tsunami.
A powerful earthquake hit Niigata Prefecture and other areas on Tuesday night. The earthquake measured upper 6 on the Japanese seismic intensity scale of 7 in Murakami, Niigata Prefecture, and lower 6 in Tsuruoka, Yamagata Prefecture. The Japan Meteorological Agency issued a tsunami advisory because the earthquake’s focus was under the sea. This was the first tsunami advisory issued since November 2016.
Fortunately, the tsunami that reached Japan’s coastline was only about 10 centimeters tall and did not cause any damage. However, the destruction wrought by the tsunami triggered by the Great East Japan Earthquake in March 2011 probably flashed through the minds of many people.
A total of more than 10,000 people evacuated in Yamagata, Niigata and Ishikawa prefectures, where tsunami advisories were issued.
These advisories said tsunami of up to 1 meter were expected and urged residents to stay away from areas near the sea. Although these advisories were of a lower level than tsunami warnings that require immediate evacuation to high ground, local authorities called on residents to quickly move to a safe place.
One Murakami resident who evacuated to a local gymnasium said, “My family had discussed how we would evacuate to high ground in times when it was possible a tsunami might come.”
If there is concern that a tsunami might strike, do not hesitate to flee to save your life — this is a lesson taught by the Great East Japan Earthquake. Being prepared at all times to take such action is crucial.
Stay alert to aftershocks
Trains on East Japan Railway Co.’s Uetsu Line made emergency stops, and train crew members fearing a possible tsunami decided on their own to guide about 50 passengers to nearby higher ground. JR East’s Niigata Branch Office has conducted passenger evacuation training every year. It is important to repeatedly and regularly hold practical training.
Following a major earthquake, aftershocks of a similar scale can occur. A cluster of strong earthquakes jolted Kumamoto Prefecture in April 2016. After the initial earthquake, which measured 7 on the seismic intensity scale, several temblors measuring upper 6 or 7 occurred. Residents affected by Tuesday’s quake in Niigata Prefecture need to remain alert to aftershocks for a while.
It also is possible that walls and buildings damaged by this earthquake could topple during aftershocks. Rain has started falling in the affected areas, so hills and cliffs where the ground has been loosened could easily collapse. It is vital that people do not approach places expected to be at risk of landslides.
Crustal stress is concentrated in an area stretching from the sea off Hokkaido to Niigata Prefecture. The latest quake’s focal area was inside this area. This area has a comparatively high number of earthquakes, including the 2004 Niigata Prefecture Chuetsu Earthquake and the 2007 Niigata Prefecture Chuetsu Offshore Earthquake.
Stress such as that which set off the latest earthquake can be found in areas all over the nation. There is concern that, in the future, a huge earthquake could occur in the Nankai Trough, which stretches along an area off the Pacific Coast from the Tokai region to Kyushu.
It is impossible to tell when an earthquake or tsunami will strike. Residents should regularly think about ways to protect themselves if a disaster hits.