Misattributed and AI-Generated Footage Circulates Following Magnitude 7.7 Earthquake in Northern Japan on April 20, 2026

Apr 24, 2026, 09:00

Introduction

A magnitude 7.7 earthquake struck northern Japan on April 20, 2026, generating tsunami waves of up to 80 centimeters at a port in Kuji, Iwate prefecture, and shaking large buildings in Tokyo. Subsequent social media posts featured videos purporting to show the event''s impact, but verification indicates these clips depict earlier earthquakes or are artificially generated.

Main Body

The earthquake, which occurred on April 20, 2026, prompted tsunami warnings and was felt hundreds of kilometers from its epicenter. However, two categories of misleading footage circulated online. The first set of videos, shared with Thai-language captions claiming to show the April 20 tremor, actually originates from two separate historical events. One clip, showing a shop collapsing, was posted on TikTok on May 7, 2025, by a beauty products wholesaler. Its timestamp of March 28, 2025, corresponds to a magnitude 7.7 earthquake in central Myanmar that resulted in over 3,800 fatalities. The shop''s Facebook page later confirmed the building was demolished due to quake damage. A second clip, depicting shoppers in a shoe store, was posted on Instagram on January 1, 2024, and is associated with the Noto Peninsula earthquake in central Japan, which killed more than 700 people. A longer version of this footage, archived on YouTube, identifies the location as the Mitsui Outlet Park in Oyabe, consistent with the store''s layout and signage. AFP previously debunked these clips when they were falsely attributed to earthquakes in Russia and the Philippines in 2025. The second category of misleading footage shows high-rise buildings swaying at an intersection. Shared with captions describing a 7.4 magnitude earthquake in Japan, this clip was posted on TikTok on December 15, 2025, months before the April 20 event. The uploader has a history of posting AI-generated content. Analysis reveals visual anomalies indicative of synthetic generation, including illegible text resembling Chinese and Korean on signs, inconsistent crosswalk markings, and a lack of camera shake during the supposed tremor. Additionally, stationary objects such as a convenience store and parked cars remain unaffected while buildings and pylons sway, contradicting the physical dynamics of an actual earthquake. AFP has debunked other misinformation related to the April 2026 earthquake.

Conclusion

In summary, the footage widely shared after the April 20, 2026, earthquake in northern Japan does not depict that event. One set of videos originates from the March 2025 Myanmar earthquake and the January 2024 Noto Peninsula earthquake, while another clip is an AI-generated fabrication posted months prior. The verified impact of the April 20 quake included tsunami waves and structural shaking in Tokyo, but no major damage was reported.

Vocabulary Learning

attributed
Regarded as being caused by or originating from a specified person, thing, or event.歸因於；認為出自（某人、某物或某事件）
Example:AFP previously debunked these clips when they were falsely attributed to earthquakes in Russia and the Philippines in 2025.
contradicting
Being in conflict with or denying the truth of a statement, fact, or physical principle.與…矛盾；否定（陳述、事實或物理原理的真實性）
Example:Stationary objects such as a convenience store and parked cars remain unaffected while buildings and pylons sway, contradicting the physical dynamics of an actual earthquake.
debunked
Exposed the falseness or hollowness of a myth, idea, or claim, especially by providing evidence.揭穿（謬誤、想法或說法的虛假性）
Example:AFP has debunked other misinformation related to the April 2026 earthquake.
purporting
Claiming or professing to be or do something, often falsely or with an element of doubt.聲稱（常帶有虛假或可疑的意味）
Example:Subsequent social media posts featured videos purporting to show the event's impact, but verification indicates these clips depict earlier earthquakes or are artificially generated.
synthetic generation
The creation of content (such as images, video, or audio) by artificial means, especially using AI algorithms, rather than recording real events.合成生成（尤指利用人工智能演算法而非真實記錄來創造內容）
Example:Analysis reveals visual anomalies indicative of synthetic generation, including illegible text resembling Chinese and Korean on signs.

Sentence Learning

The first set of videos, shared with Thai-language captions claiming to show the April 20 tremor, actually originates from two separate historical events.
This sentence features a reduced relative clause ('shared with Thai-language captions claiming to show the April 20 tremor') that modifies 'videos', with an embedded participial phrase ('claiming to show...') adding further modification. The main clause ('The first set of videos...actually originates from two separate historical events') uses a simple present tense verb, but the complexity lies in the nested, non-restrictive modifiers that delay the main verb and increase lexical density. Structural Analysis in English句子包含一個縮減的關係從句（「shared with Thai-language captions claiming to show the April 20 tremor」）修飾「videos」，其中嵌入了一個分詞短語（「claiming to show...」）作進一步修飾。主句（「The first set of videos...actually originates from two separate historical events」）使用一般現在時動詞，但複雜性在於嵌套的非限制性修飾語延遲了主要動詞的出現，並增加了詞彙密度。
Analysis reveals visual anomalies indicative of synthetic generation, including illegible text resembling Chinese and Korean on signs, inconsistent crosswalk markings, and a lack of camera shake during the supposed tremor.
This sentence employs a complex noun phrase structure with post-modification: 'visual anomalies indicative of synthetic generation' uses an adjective phrase ('indicative of...') to qualify the noun. The list that follows ('including...') uses parallel participial phrases ('illegible text resembling...', 'inconsistent crosswalk markings', 'a lack of camera shake...') to elaborate, creating high syntactic density and requiring the reader to parse multiple coordinated elements. Structural Analysis in English句子採用複雜的名詞短語結構，帶有後置修飾：「visual anomalies indicative of synthetic generation」使用形容詞短語（「indicative of...」）來限定名詞。後續的列舉（「including...」）使用並列的分詞短語（「illegible text resembling...」、「inconsistent crosswalk markings」、「a lack of camera shake...」）進行闡述，從而形成高句法密度，要求讀者解析多個並列成分。
Additionally, stationary objects such as a convenience store and parked cars remain unaffected while buildings and pylons sway, contradicting the physical dynamics of an actual earthquake.
This sentence features a concessive adverbial clause ('while buildings and pylons sway') that contrasts with the main clause ('stationary objects...remain unaffected'). The sentence ends with a present participial phrase ('contradicting the physical dynamics...') that functions as a sentential adverb, providing a commentary on the entire preceding clause. This structure demonstrates mastery of clause subordination and non-finite verb usage for rhetorical effect. Structural Analysis in English句子包含一個讓步狀語從句（「while buildings and pylons sway」），與主句（「stationary objects...remain unaffected」）形成對比。句子以一個現在分詞短語（「contradicting the physical dynamics...」）結尾，該短語充當句子副詞，對整個前面的從句進行評論。此結構展示了從句從屬和非限定動詞用於修辭效果的高超運用。
A longer version of this footage, archived on YouTube, identifies the location as the Mitsui Outlet Park in Oyabe, consistent with the store's layout and signage.
This sentence uses a reduced relative clause ('archived on YouTube') to modify 'footage'. The main clause ('A longer version...identifies the location...') is followed by an adjective phrase ('consistent with the store's layout and signage') that functions as a subject-related complement, providing additional information about the location. This structure exemplifies concise post-modification and the use of ellipsis for stylistic economy. Structural Analysis in English句子使用一個縮減的關係從句（「archived on YouTube」）修飾「footage」。主句（「A longer version...identifies the location...」）後跟一個形容詞短語（「consistent with the store's layout and signage」），該短語充當與主語相關的補足語，提供關於地點的附加信息。此結構體現了簡潔的後置修飾以及為追求文體簡潔而使用的省略手法。
One clip, showing a shop collapsing, was posted on TikTok on May 7, 2025, by a beauty products wholesaler.
This sentence features a non-restrictive participial phrase ('showing a shop collapsing') that interrupts the main clause ('One clip...was posted...by a beauty products wholesaler'). The use of a present participle ('showing') with an object ('a shop collapsing') creates a compact, descriptive insertion that adds detail without a full relative clause. The passive voice ('was posted') shifts focus to the action, while the agent ('by a beauty products wholesaler') is deferred, demonstrating control over information flow. Structural Analysis in English句子包含一個非限制性分詞短語（「showing a shop collapsing」），打斷了主句（「One clip...was posted...by a beauty products wholesaler」）。使用現在分詞（「showing」）帶賓語（「a shop collapsing」）形成一個緊湊的描述性插入語，無需完整的關係從句即可添加細節。被動語態（「was posted」）將焦點轉移到動作上，而施動者（「by a beauty products wholesaler」）被後置，展現了對信息流動的控制。