Earthquake Activity in Northern Japan and the Hokkaido Region

Apr 26, 2026, 22:54
JapanWorld

Introduction

On April 27, a magnitude 6.1 earthquake hit the Hokkaido region of Japan, following a period of increased seismic activity in the northern part of the country.

Main Body

The earthquake occurred at 05:24 JST in southern Hokkaido, with the center located about 18 kilometers west of Sarabetsu. The Japan Meteorological Agency (JMA) reported a seismic intensity of '5+' in the central Tokachi region, while the US Geological Survey (USGS) estimated the depth at around 80 to 81 kilometers. No tsunami warnings were issued, and the USGS stated that the risk to people and property was low because the area east of Sapporo is not densely populated. However, the JMA warned that landslides and rockfalls were more likely in areas that felt strong tremors. This event happened only one week after a larger earthquake on April 20, when a magnitude 7.5 to 7.7 quake struck off northern Iwate prefecture. That earlier event caused six injuries and created an 80-centimeter tsunami at Kuji port. As a result, the JMA issued a special advisory, claiming that the probability of a 'megaquake' with a magnitude of 8.0 or higher was currently above normal levels. While nuclear plant operators emphasized that there were no problems at the Higashidori, Onagawa, and Fukushima facilities, the Tohoku Shinkansen train service between Tokyo and Shin-Aomori was suspended. From a geological point of view, Japan experiences many earthquakes because it is located on four major tectonic plates along the Pacific 'Ring of Fire.' The country averages about 1,500 earthquakes per year, which is roughly 18 percent of all global seismic activity. This vulnerability was clearly seen during the 2011 magnitude 9.0 undersea earthquake, which led to approximately 18,500 deaths or missing persons and a nuclear meltdown at the Fukushima plant.

Conclusion

The JMA continues to monitor the situation closely. Residents in northern regions are advised to stay alert and avoid coastal areas as long as the seismic advisories remain in effect.

Vocabulary Learning

intensity (n.)
strength or degree of something, especially in the context of earthquakes強度
Example:The earthquake had an intensity of 5+.
nuclear (adj.)
relating to the atom or atomic energy, especially in the context of power plants核能的
Example:The nuclear plant operators emphasized that there were no problems at the Fukushima facility.
seismic (adj.)
pertaining to earthquakes / related to the movement of the Earth's crust震動的
Example:The region experiences frequent seismic activity.
tsunami (n.)
a large sea wave caused by an underwater disturbance such as an earthquake海嘯
Example:The quake triggered a tsunami that reached 80 centimeters.
vulnerability (n.)
the state of being susceptible to harm or damage易受損性
Example:Japan's vulnerability to earthquakes is high due to its location.

Sentence Learning

No tsunami warnings were issued.
Passive Voice: This sentence uses the passive voice; the subject 'No tsunami warnings' receives the action of the verb 'were issued', indicating that the warnings were produced by an unspecified agent.被動語態: 這句話使用被動語態，動詞 'were issued' 表示動作被施加於主語 'No tsunami warnings'，主語為動作的承受者。
However, the JMA warned that landslides and rockfalls were more likely in areas that felt strong tremors.
Relative Clause: The clause 'that felt strong tremors' is a relative clause modifying 'areas', providing essential information about which areas are more likely to experience landslides and rockfalls.關係子句: 子句 'that felt strong tremors' 係關係子句，用來修飾 'areas'，提供哪些地區更易發生滑坡與落石的必要資訊。
The Japan Meteorological Agency (JMA) reported a seismic intensity of '5+' in the central Tokachi region, while the US Geological Survey (USGS) estimated the depth at around 80 to 81 kilometers.
Contrast Conjunction: The conjunction 'while' contrasts the two actions of reporting seismic intensity and estimating depth, showing that they occurred simultaneously but by different agencies.對比連接詞: 連接詞 'while' 用於對比兩個動作：報告地震強度與估算深度，表明它們同時發生但由不同機構執行。
As a result, the JMA issued a special advisory, claiming that the probability of a 'megaquake' with a magnitude of 8.0 or higher was currently above normal levels.
Causal Linking: The phrase 'As a result' indicates a cause-and-effect relationship, explaining that the JMA issued a special advisory as a consequence of the heightened probability of a megaquake.因果連接詞: 片語 'As a result' 表示因果關係，說明 JMA 發出特別勸告是因為大地震的可能性升高。
Residents in northern regions are advised to stay alert and avoid coastal areas as long as the seismic advisories remain in effect.
Conditional Conjunction: The phrase 'as long as' introduces a condition, meaning residents should stay alert and avoid coastal areas only while the seismic advisories are in effect.條件連接詞: 片語 'as long as' 引入條件，表示只要地震勸告仍在效力期間，居民應保持警覺並避免沿海地區。