For general earthquake response — what to do by intensity level, hotel and transit situations — see the Japan Earthquake Safety Guide. This article focuses on what's specific to Kumamoto.
Kumamoto Has Already Been Through It
Most cities in Japan have earthquake risk on paper. Kumamoto has it on record.
On April 14, 2016, at 9:26 p.m., a magnitude 6.5 struck Kumamoto directly. Japan's Meteorological Agency declared it the mainshock. Many people thought the worst was over.
Two days later, at 1:25 a.m. on April 16, a M7.3 hit the same area. Both earthquakes registered seismic intensity 7 — the maximum on Japan's scale — in Mashiki-machi just east of the city. The April 14 quake turned out to have been a foreshock.
50 people died directly; 273 total when disaster-related deaths are counted. Around 44,000 buildings were damaged or destroyed.
Kumamoto has since rebuilt extensively. But the fault that caused 2016 is still there, and the lessons from that sequence are unlike anywhere else in Japan.
What Makes Kumamoto Earthquake Risk Different
The Futakawa Fault Runs Through the City
Kumamoto's primary seismic threat comes from the Futakawa fault (布田川断層帯), which cuts east-west directly under the urban area, passing north of Kumamoto Castle and extending toward the Aso caldera. It connects to the Hinagu fault system reaching south toward Yatsushiro.
The 2016 M7.3 was a direct rupture of this fault. Because it struck directly beneath the city rather than offshore, the same amount of energy caused far more surface shaking than a comparably sized ocean quake would.
This is different from the risk profile of cities like Osaka or Fukuoka, which face the slow-building threat of the Nankai Trough. Kumamoto's danger is the fault underneath it.
The Foreshock That Fooled Everyone — Including the Experts
The 2016 sequence introduced something unusual into Japanese earthquake history: a foreshock that wasn't recognized as a foreshock until it was too late.
When M6.5 struck on April 14, JMA had no way to know a larger quake would follow. The official announcement treated it as the mainshock. Standard aftershock expectations applied. Then the M7.3 arrived.
This isn't a failure of communication — it reflects a genuine scientific limit. No one can currently predict whether any given large quake will be followed by something bigger. What it means for travelers in Kumamoto specifically:
After a significant quake, don't assume the sequence is over. In particular:
- Don't return to a cracked building before it's been inspected
- Even if the first quake felt survivable, treat the following 24–48 hours as elevated risk
- Follow guidance from your accommodation and local officials — they'll be monitoring for patterns
The Compound Risk: Mt. Aso
The other thing that makes Kumamoto unusual is Mt. Aso — Japan's largest caldera volcano, with Nakadake 1st Crater still actively erupting. When you combine an active fault zone with an active volcano, you get a compound risk that exists almost nowhere else in Japan's tourist circuit.
Aso's eruption alert level (噴火警戒レベル, Level 1–5) changes in real time based on volcanic activity. Level 2 or above means the crater rim is off-limits; Level 3 means the surrounding area is restricted. A Level 3 was last declared in October 2021 following a significant eruption.
Check before you go: JMA Volcanic Activity Information for Aso — the level can change the morning of your visit.
If a significant earthquake occurs while you're near the Aso crater area:
- Move away from the crater immediately, regardless of whether eruption activity changes
- Volcanic gas (mainly SO₂) can become dangerous following seismic activity — move upwind and uphill, away from the crater
- The crater ropeway stops automatically when sensors detect shaking; if you're on the upper plateau and the ropeway is suspended, head toward the volcano museum or downhill toward Aso city
What to Do at Each Major Tourist Site
Kumamoto Castle (熊本城)
The castle's main tower reopened in April 2021 after five years of reconstruction following 2016. Full restoration of the complex is expected around 2052 — repair work continues throughout the grounds.
- Active construction zones have additional falling-object risk during an earthquake. If shaking starts in or near these areas, move toward open park space immediately.
- The stone walls partially collapsed in 2016. If shaking begins while you're near the stone ramparts, move away from the walls.
- If you're inside the main tower during shaking: do not use the elevator; take the stairs to ground level, then move to the open park area.
- The Honmaru Palace grounds (本丸広場) are designated as a regional evacuation area.
Suizenji Jojuen Garden (水前寺成趣園)
An Edo-period feudal lord's garden in central Kumamoto.
- The open garden grounds function as natural evacuation space — better to be here than in surrounding commercial buildings during a quake.
- Move away from the Noh stage, shrine structures, and stone lanterns, which can shed roof tiles or topple.
- Post-quake, garden entry may be restricted; follow staff instructions.
Kamitori / Shimotori Arcade (上通り・下通り商店街)
Kumamoto's main covered shopping arcade — about 1.3 km of storefronts under a continuous roof.
- The roof structure (glass and metal panels) can shed material during strong shaking. Move toward the nearest exit as quickly as possible and get into open space.
- Shop display cases and freestanding shelving can fall into the aisle — stay toward the center of the passage.
- Sections of the arcade sustained damage in 2016; structural reinforcement was completed after that, but the roof panels remain a concern in strong shaking.
Mt. Aso / Aso Volcano Museum Area
The Aso Museum sits inside the caldera. Nakadake crater and the observation deck are accessible via ropeway on days when the alert level permits.
- Earthquake during ropeway operation: the cable car stops automatically. Gondolas are suspended safely — wait for staff instruction before doing anything else.
- If you're at the crater observation deck, don't wait to assess the volcanic situation. Move away from the crater edge immediately.
- The Aso Volcano Museum (a concrete building on the caldera floor) is structurally more stable than the observation platform. If volcanic gas becomes an issue, the museum has sealed indoor space.
- Know your descent routes before you ascend: Route 57 and Route 212 are the main roads connecting Aso to Kumamoto city. Both were cut by landslides in 2016.
Kurokawa Onsen (黒川温泉)
One of Kyushu's most popular hot spring resorts, in mountain valleys about 40 km from the Aso caldera.
- During bathing: bathroom floors are wet and slippery. If shaking starts, exit the bath immediately before trying to move quickly — a fall on wet stone is more likely to injure you than the earthquake itself.
- Kurokawa sits in a mountain valley accessed by narrow roads. In 2016, road damage temporarily cut off access to the area. Check in with your inn about evacuation routes when you arrive.
- The mountainous terrain means shelter-in-place is often the right call initially — confirm with inn staff rather than attempting to drive out on roads you don't know.
Getting Around After an Earthquake
| Transport | Route | What Happens After an Earthquake |
|---|---|---|
| Kyushu Shinkansen | Hakata ↔ Kumamoto ↔ Kagoshima | Auto-stops at intensity 4+; resumes after track inspection |
| Kumamoto City Tram | Station ↔ Suizenji ↔ Kengun | Stops immediately if track anomaly detected; wait in car or follow staff guidance |
| Kumamoto Electric Railway | Kumamoto ↔ Kami-Kumamoto | Short line; stops immediately |
| Sanko Bus (Aso service) | Kumamoto ↔ Aso | Road-dependent — landslide risk means service can be cancelled for days |
If you're in the Aso area when a significant earthquake strikes, assume the road back to Kumamoto may be temporarily closed and plan accordingly.
Before You Go
- JMA Earthquake Intensity Map — check Kumamoto's real-time intensity
- JMA Aso Volcanic Alert Level — check the morning of your Aso visit
- Kumamoto Castle official site — check which areas are open and where construction zones are
- At check-in: ask your accommodation for the nearest designated evacuation site (指定避難場所)
- JNTO Safety Tips app — English earthquake alerts on your phone
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