日本にほんは 地震じしんが 多おおい 国くにです。How often do earthquakes happen in Japan, and where?

日本にほんで 働はたらく 人ひと、これから 働はたらく 人ひとへ。日本にほんに いると、いつか 地震じしんに あいます。
この ページで、地震じしんが どのくらい 多おおいか、どこで 起おきるかが わかります。

For people working in Japan, and for those about to. Live here and you will meet an earthquake sooner or later. This page shows how often they happen, and where.

クイズQUIZ

日本にほんでは、からだで わかる 地震じしんが 1いち年ねんに 何回なんかい ありますか。
In a typical year, how many earthquakes here are strong enough to feel?

A約 20 回 B約 200 回 C約 2,000 回

えらんで ください。Tap one.

Earthquakes in Japan: how often, and where

Work in Japan long enough and you will feel an earthquake. It might be next week, it might be in six months, but it will happen.

The first one usually catches people off guard. A phone alarm goes off in a tone you have never heard. The TV cuts to a map covered in numbers you cannot read. And everyone around you starts moving before you have worked out what is going on.

That is not panic — it is habit. Japan has had a long time to get used to earthquakes, and most of what people here do is simple and practical: what the alert sound means, what to do in the first ten seconds, what to keep in a drawer at home. None of it is hard to learn. It just is not written down anywhere a newcomer would think to look.

This is the first of four short articles, and it covers one question: how often do earthquakes happen here, and where? The next three cover reading the warnings, what to do while the ground is moving, and what to sort out in advance.

You do not need to worry about earthquakes. You do need to know a few things about them.

011いち年ねんに 約やく2,000回かい

人ひとが ゆれを 感かんじた 地震じしん（震度しんど1以上いじょう）の 数かずです。2025年ねんは 4,456回かいでした。

This is the number of earthquakes people actually felt (shindo 1 or above). There were 4,456 in 2025.

1年いちねんの 数かずを 365日にちで わると、1日いちにちに 5〜6回かいに なります。でも、まいにち 5〜6回かい ゆれる わけでは ありません。ぜんぜん ない 日ひも あります。
Divide the year by 365 and you get five or six a day — but that is arithmetic, not experience. Some days bring none at all.

ゆれの 大おおきさは いろいろです。気きづかない くらい 小ちいさい ゆれから、物ものが 落おちる 大おおきい ゆれまで あります。多おおくは 小ちいさい ゆれです。

The size of the shaking varies widely, from movement you would not notice to shaking that knocks things over.

02どこで 起おきますか

ここでは、からだで はっきり わかる ゆれ（震度しんど3以上いじょう）だけを 数かぞえました。

Here we counted only the shaking you clearly feel in your body — shindo 3 and above.

からだで はっきり わかる ゆれは、どの ちほうにも あります。

03だいじな こと

04自分じぶんの 身みを まもる ために

地震じしんが 起おきた とき、自分じぶんの 身みを まもる ために ひつような 知識ちしきを、じゅんばんに 整理せいりします。この 連載れんさいは 全ぜん6回かいです。
Six short articles: what to know now, what to have ready, and what to do when the ground starts moving.

1. どのくらい 多いかHOW OFTEN 1日本にほんは 地震じしんが 多おおい 国くにです How often earthquakes happen, and where
2. ゆれて いる ときWHILE IT SHAKES公開ずみPublished 2地震じしんが きました。さいしょに することは 何なんですか The first minute — and why the answer depends on where you are
3. 起きる まえBEFORE IT HAPPENS公開ずみPublished 3家いえと 職場しょくばの じゅんび What to sort out first, and what to ask your employer
4. 起きた あとAFTER IT STOPSじゅんび中Coming soon 4地震じしんの あとで、こころが つかれます What almost everyone feels afterwards, and where to get help
5. じょうほうINFORMATIONじゅんび中Coming soon 5警報けいほうと 情報じょうほうの 読よみかた How to read the alerts, and where to look for information

05英語えいごで よむ

About 2,000 a year that you can feel

• The Seismological Society of Japan gives about 2,000 as a rough guide.
• Actual totals swing: 4,456 in 2025, 3,678 in 2024, 10,681 in 2011.
• Divide by 365 and you get five or six a day. Nobody experiences it that evenly.
• Most are too small to notice unless you are close by, or sitting still indoors.

Everywhere, not somewhere

• The map counts only intensity 3 and above — the point where you feel it in your body.
• Hokkaido 33 · Tohoku 117 · Kanto & Chubu 92 · Kinki, Chugoku & Shikoku 14 · Kyushu 315 · Okinawa 4.
• Every region has a number.

A low number is not safety

• These are counts for one year. One year says little about long-term risk.
• Kyushu's figure is high mainly because of a long swarm near the Tokara Islands.
• Read the map as evidence that earthquakes reach everywhere — not as a ranking of danger.

The rest of this series

This article is the first of four. The next three are being written now, and they follow the order in which you will need them:

• Before — what to arrange at home and at work, and what to ask your employer.
• During — what to do in the first ten seconds.
• After — how to read the alerts, and where to look for information.

Each one is written in plain Japanese with furigana, and in English, like this one.

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06この 記事きじは 役やくに 立たちましたか

One tap helps us write the next one.

◎役やくに 立たったHelpful ○すこしA little △むずかしかったToo hard

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