Earthquake Causes Tsunami That Strikes Japan – 12/21/1946

US History |

When it comes to natural disasters, it can be very difficult or impossible to predict when one may occur exactly or in advance. Some natural disasters, like tornados, are possible to have some warning before one is formed but can be a toss-up from ample time to prepare to almost immediately happening. 

Another disaster that can be detected is earthquakes; although without proper instruments, the only way to know is when the ground starts to shake but by then would be too late to escape. One type in particular; a tsunami, does have some warning but nothing can really be done to avoid the destruction that it can unleash. There have been recorded many of these undersea earthquakes that cause a tsunami to occur and one in particular unleashes its fury on Japan.

On December 21st, 1946, an earthquake that occurs undersea unleashes a destructive tsunami that destroys Honshu, Japan. The result of this destructive force was half a million people were left without homes and roughly 2,000 people lost their lives. This event would have been bad enough if it happened during a different point in history; however, it was more of devastation to a group of people that was already suffering immensely due to the horrors that happened after World War II.

Previously this year, Hawaii had been hit by a tsunami on April 1st but those waves had started hundreds of miles away; the far distance from the islands still resulted in the deaths of 159 people. Unfortunately, the center of the earthquake that happened on December 21st at 4:20 a.m. occurred closer at 27 miles south of Honshu’s Kii Peninsula. The magnitude of the tremor was 8.5 and resulted in structures collapsing on Honshu that included some of the homes occupied forces of the U.S. were staying in.

What made the situation worse was that not one but three huge tsunamis were traveling in the direction of Honshu as well as the smaller islands of Shikoku and Kyushu. The features of the local geography were able to determine how much force the waves had by the time they reached landfall and the amount of destruction they caused. There were those who, if able to recognize them, had available some warning that a tsunami was about to hit so long as they paid attention to the sign; some areas had the water receding first which is one sign of an imminent tsunami. When Honshu was struck by the tsunami, the waves were 20-feet where roughly 2,000 vessels were capsized from being thrown around due to the water’s mass and structures on the shorelines were completely obliterated.

While Japan was already going to need time to recover from the damage caused by the events of World War II, this new devastation only lengthened the time Japan’s people and the economy would need to heal. While thousands of lives were lost, the damage the tsunami caused was having 60,000 square miles being flooded because of the waves and utterly demolished was a total of 40,000 homes. 

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Meg Wong


One of the hardest working individuals, Meg sets the bar high when it comes to work ethic and being a great teammate. She learned these values at a young age while she was the captain of her high school volleyball team. Leading her team to 3 state championships and coming away victorious twice. You can still see the leader in her through everything she does for us here.