September 20, 1498 Tsunami: Enshunada Sea, Japan
A tsunami caused by a magnitude 8.3 earthquake began at Enshunada Sea, Japan on September 20, 1498. The water rose as high as 10 meters. Its effects were recorded at 6 places. It killed 5,000 people, counting the earthquake or eruption that caused it.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
Travel times
How long the first wave took to reach each part of the ocean, one line for each hour up to 24, estimated from the source and the depth of the sea.
The travel times are computed in your browser, which needs JavaScript.
- 1 to 4 hours
- 5 to 6 hours
- 7 to 14 hours
- 15 hours and more
Computed in your browser the way NOAA’s own travel time maps are: the wave travels at the square root of gravity times the depth, over NOAA’s ETOPO1 depths averaged to a 10 arc-minute grid. Checked against NOAA NCEI’s maps for 21 tsunamis over the first 24 hours, these lines fall within 10 minutes of NCEI’s at half the points compared and within 52 minutes at 9 in 10. They give when the first wave could arrive, not how high it is; bays, harbors and island chains finer than the grid can see it later. Not for use in a warning: see tsunami.gov.
The tsunami
- Date
- September 20, 1498
- Source
- Enshunada Sea, Japan
- Cause
- Earthquake
- Earthquake
- Magnitude 8.3
- Maximum water height
- 10 m (32.8 ft)
- Runups recorded
- 6
- Tsunami intensity (Soloviev-Imamura)
- 4
- Tsunami magnitude (Iida)
- 3
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 34.000° N, 138.100° E
The toll
- Deaths
- 5,000
- Damage
- Extreme (about $25 million or more); Severe (about $5 to $25 million) with the earthquake or eruption that caused it
- Houses destroyed
- 1,000
Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.
What the record says
NCEI’s account, from the sources it cites.
September 20, 1498, about 8:00 [local time]. 34.1 N, 138.2 E, magnitude 8.6, tsunami intensity 3. There was a catastrophic earthquake which was felt in the prefectures of Wakayama, Nara, Mie, Aichi, Shizouka, Yamanashi, Kanagawa, Tokyo, Saitama, Chiba, Gumma, Tochigi, Ibaraki and Fukushima. The pleistoseismic zone included the prefectures from Mie to Kanagawa and had a length of about 360 km. However, the main damage was done by the tsunami waves which were observed from the Kii Peninsula to the Miura Peninsula.
At Ominato, Mie Prefecture, 1000 homes were flooded and washed away and 500 people died. The spit, separating Hamana Lake from the sea, was breached. At Kamak'ura, the wave reached the Daibutsu temple; 200 people died. [effects same as 1495] On Hachijo Island, one person died as a result of the tsunami.
(above from Reference #414)
Sept 20, 1498. 34 N, 138.1 E, magnitude 8.3. 19ha in Tsu sunk into sea. 1,000 houses washed away. 5,000 drowned at Ohminato, Ise, 10m in wave height. Waves reached 2km inland in Nishina County, Izu. 26,000 deaths by tsunami at Yaizu area in Suruga Bay. Lake Hamana opened to sea. (reference #150)
Sept 20, 1498. Sea waves on the coasts of Kii, Ise, Mikawa, Suruga, Izu, Sagami; great loss of life. (reference #1897)
Sept 20, 1498. Tokai region, 41,000 deaths. (reference #1051)
It was mentioned that death toll by wash-out was 26,000, but it may be a typo: 260. Hamana-ko (lake) was slashed by the tsunami and there was a temporary passage to the ocean (henceforth Imagire (now thrashed) became the name of the place)... 1,000 home were washed out in Ise, and 5,000 people drowned... (reference #3785)
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Lake Hamana | Japan | 89 | Eyewitness observation of water height | ||||
| Yaizu | Japan | 99 | Eyewitness observation of water height | 26,000 | |||
| Nishina County | Japan | 105 | 2,000 | Eyewitness observation of water height | |||
| Ominato (Ise) | Japan | 137 | 10 | Eyewitness observation of water height | 5,000 | ||
| Yaene, Hachijo Island | Japan | 184 | Eyewitness observation of water height | 1 | |||
| Kamakura | Japan | 197 | Eyewitness observation of water height | 200 |
More
Every tsunami in 1498The 1400sTsunamis of JapanThe earthquakeThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 146.