September 1, 1923 Tsunami: Sagami Bay, Japan

Name: September 1, 1923 Tsunami: Sagami Bay, Japan
Start: 1923-09-01
Location: Sagami Bay, Japan

September 1, 1923 · 13 m · 105,385 deaths · $600 million · 695,000 houses destroyed · Definite tsunami

A tsunami caused by a magnitude 7.9 earthquake began at Sagami Bay, Japan on September 1, 1923 at 02:58:37 UTC. The water rose as high as 13 meters. Its effects were recorded at 142 places in at least 4 countries. It killed 105,385 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

Tsunami warnings in force

The tsunami

Date: September 1, 1923, 02:58:37 UTC
Source: Sagami Bay, Japan
Cause: Earthquake
Earthquake: Magnitude 7.9, 33 km deep
Maximum water height: 13 m (42.7 ft)
Runups recorded: 142
Tsunami intensity (Soloviev-Imamura): 3
Tsunami magnitude (Iida): 3.6
Waters: Ocean
How certain: Definite tsunami
Source location: 35.100° N, 139.500° E

The toll

Deaths: 325; 105,385 with the earthquake or eruption that caused it
Missing: Very many (over 1,000) with the earthquake or eruption that caused it
Injuries: Many (about 101 to 1,000); 52,074 with the earthquake or eruption that caused it
Damage: Severe (about $5 to $25 million); $600 million with the earthquake or eruption that caused it
Houses destroyed: 868; 695,000 with the earthquake or eruption that caused it

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.

Reference #414:

On September 1, 1923 at 02:58:49 at 35.25 N, 139.5 E, magnitude 8.2, there was a catastrophic earthquake in the Kanto region. The source of the earthquake, and the moderate tsunami which it generated, included Sagami Gulf and the Boso Peninsula, as well as adjacent areas of the sea and land, and apparently was oriented latitudinally. The assumed length of the source was 150-200 km. Almost 100,000 people died, and at least 47,000 injured; 2,144 people and 166 were injured in washed away homes.

Reference #13911 (p 15), #13909:

For the entire Kanto region, the total number of casualties due to fire is 91,781 (87%), followed by due to house collapse (11,086 or 11 %). Although the ratio is less than 1%, 688 casualties were due to landslides, and 325 were due to tsunamis.

Note: possible that ref #414 reference to washed away homes is due to debris flows and riverine flooding.

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
Djogashima Island	Japan	11	12		Eyewitness observation of water height
Miura	Japan	12	3		Eyewitness observation of water height
Aburatsubo	Japan	13	1.8		Eyewitness observation of water height
Koajiro	Japan	14	1.8		Eyewitness observation of water height
Nagai	Japan	16	1.2		Eyewitness observation of water height
Akiya	Japan	18	3		Eyewitness observation of water height
Hayama	Japan	20	5		Eyewitness observation of water height
Yuigahama	Japan	21	6		Eyewitness observation of water height		100
Horiuchi	Japan	21	3		Eyewitness observation of water height
Enoshima Island	Japan	22	5		Eyewitness observation of water height
Zushi	Japan	22	5		Eyewitness observation of water height
Kotsubo	Japan	22	7.1	100	Eyewitness observation of water height
Katase	Japan	23	1.5		Eyewitness observation of water height
Shichirihama	Japan	23			Eyewitness observation of water height
Kamakura	Japan	24	6		Eyewitness observation of water height		150
Fujisawa	Japan	24	3		Eyewitness observation of water height
Kugenuma	Japan	25	6		Eyewitness observation of water height
Otsu	Japan	25	1.2		Eyewitness observation of water height
Uraga	Japan	25	0.8		Eyewitness observation of water height
Yokosuka	Japan	26	1.7		Tide gauge (half the maximum wave height)	day 1, 03:01
Oiso	Japan	28	3	100	Eyewitness observation of water height
Sunosaki	Japan	28	8.1		Eyewitness observation of water height
North Coast Sagami Bay	Japan	28	9		Eyewitness observation of water height
Hiratsuka	Japan	28			Eyewitness observation of water height
Hatsushima Island	Japan	31	1.8		Eyewitness observation of water height
Tomiura	Japan	31	2.8		Eyewitness observation of water height
Haraoka	Japan	31	1.3		Eyewitness observation of water height
Fukuura	Japan	31			Eyewitness observation of water height
Hota	Japan	32	3		Eyewitness observation of water height
Manazuru	Japan	32	6		Eyewitness observation of water height		12
Tateyama	Japan	34	1.8		Eyewitness observation of water height
Heisaura Gulf	Japan	34			Eyewitness observation of water height
Ainohama	Japan	35	10.3		Eyewitness observation of water height
Nebukawa	Japan	35			Eyewitness observation of water height
Odawara	Japan	35			Eyewitness observation of water height
Imam'Ura	Japan	36	6		Eyewitness observation of water height
Mera	Japan	36	6		Eyewitness observation of water height
Tomisaki	Japan	36			Eyewitness observation of water height
Futsu	Japan	37	0.6		Eyewitness observation of water height
Okada	Japan	37	12		Eyewitness observation of water height		14
Kusumi	Japan	38	9		Eyewitness observation of water height
Wadaki	Japan	38	4.5		Eyewitness observation of water height
Atami	Japan	39	9		Eyewitness observation of water height		60
Ito (Itoshi)	Japan	39	9		Eyewitness observation of water height
Shimotaga Niikama	Japan	39	7.2		Eyewitness observation of water height		4
Ajiro	Japan	40	7.2		Eyewitness observation of water height		4
Oshima Island	Japan	40	13		Eyewitness observation of water height
Usami	Japan	40	7.5		Eyewitness observation of water height
Futo	Japan	40	0.6		Eyewitness observation of water height
Shirahama	Japan	42	1.5		Eyewitness observation of water height
Fujiwara	Japan	43	7.2		Eyewitness observation of water height
Chikura	Japan	44	2		Eyewitness observation of water height
Kawana	Japan	45	6		Eyewitness observation of water height
Habuminato, Oshima Island	Japan	47	5		Eyewitness observation of water height
Okawa	Japan	49	4.1		Eyewitness observation of water height
Kisarazu	Japan	51	1.8		Eyewitness observation of water height
Hinode	Japan	53			Eyewitness observation of water height
Kamogawa	Japan	55	1.5		Eyewitness observation of water height
Niemonijima	Japan	55	2		Eyewitness observation of water height
Inatori	Japan	56	6		Eyewitness observation of water height
Makuchi	Japan	58	4.5		Eyewitness observation of water height
Kominato	Japan	62	1.8		Eyewitness observation of water height
Misaki	Japan	62	3		Eyewitness observation of water height
Mitaka	Japan	62	4.5		Eyewitness observation of water height	day 1, 04:28
Sibaura	Japan	63	0.79		Tide gauge (half the maximum wave height)	day 1, 03:31
Shirahama	Japan	66	3		Eyewitness observation of water height
Sotoura	Japan	67	6		Eyewitness observation of water height
Tokyo Bay	Japan	67	1.5		Eyewitness observation of water height
Kakisaki	Japan	68	4.6		Eyewitness observation of water height
Wada	Japan	68	2		Eyewitness observation of water height
Gofukubashi	Japan	69	0.52		Tide gauge (half the maximum wave height)	day 1, 03:41
Shimoda	Japan	70	2.5		Eyewitness observation of water height
Chiba	Japan	72	0.75		Tide gauge (half the maximum wave height)
Matsube	Japan	72	1.5		Eyewitness observation of water height
Urayasu	Japan	73	0.3		Eyewitness observation of water height
Katsuura (Katsuurashi)	Japan	75	1.2		Eyewitness observation of water height
Minato	Japan	75	2		Eyewitness observation of water height
Funabashi	Japan	79	0.5		Eyewitness observation of water height
Chiba Prefecture	Japan	90			Eyewitness observation of water height	day 1, 03:26
Shimizu	Japan	93				day 1, 03:17
Kanaya	Japan	128	1		Eyewitness observation of water height
Togawa	Japan	140	1.5		Eyewitness observation of water height
Choshi	Japan	144	0.3		Tide gauge (half the maximum wave height)	day 1, 03:40
Takasaki	Japan	144	3		Eyewitness observation of water height
Iwai	Japan	168	3		Eyewitness observation of water height
Arai	Japan	183	3		Eyewitness observation of water height
Same (Aomori Prefecture)	Japan	232	0.4		Tide gauge (half the maximum wave height)	day 1, 05:15
Simoda	Japan	232	3		Eyewitness observation of water height
Onahama	Japan	239	0.18		Tide gauge (half the maximum wave height)
Toba	Japan	255	0.6		Tide gauge (half the maximum wave height)	day 1, 04:00
Katsuyama	Japan	294	2.2		Eyewitness observation of water height
Owase	Japan	323	0.54		Tide gauge (half the maximum wave height)	day 1, 03:44
Osaka	Japan	369	0.33		Tide gauge (half the maximum wave height)	day 1, 05:01
Urato	Japan	383	0.21		Tide gauge (half the maximum wave height)
Kushimoto	Japan	387	0.48		Tide gauge (half the maximum wave height)	day 1, 04:00
Ayukawa	Japan	398	0.2		Tide gauge (half the maximum wave height)	day 1, 05:06
Ishinomaki	Japan	400				day 1, 04:28
Toyooka	Japan	432	1.7		Eyewitness observation of water height
Koura	Japan	444	2.1		Eyewitness observation of water height
Muya (Naruto)	Japan	459	0.6		Eyewitness observation of water height
Okazaki	Japan	459			Eyewitness observation of water height
Kawauchi	Japan	465	0.5		Eyewitness observation of water height
Honjo	Japan	482	0.27		Tide gauge (half the maximum wave height)	day 1, 03:01
Kochi	Japan	574			Eyewitness observation of water height
Urado	Japan	575	0.25		Tide gauge (half the maximum wave height)	day 1, 04:18
Fukugawa	Japan	722	0.6		Tide gauge (half the maximum wave height)
Oita	Japan	756	0.6		Eyewitness observation of water height
Hiji	Japan	759	0.6		Eyewitness observation of water height
Takata	Japan	760			Eyewitness observation of water height
Hososhima	Japan	783	0.32		Tide gauge (half the maximum wave height)	day 1, 04:50
Tsurushima	Japan	829	0.15		Tide gauge (half the maximum wave height)	day 1, 04:40
Tanegashima Island	Japan	921			Eyewitness observation of water height
Futami Port	Japan	923			Eyewitness observation of water height
Futami Bay, Chichijima Island	Japan	924	0.9		Eyewitness observation of water height
Hahajima Island	Japan	965			Eyewitness observation of water height
Honolulu, Oahu, HI, HI	United States	6,236	0.03		Tide gauge (half the maximum wave height)
Tofino (Clayoquot),british Columbia, BC	Canada	7,458	0.04		Tide gauge (half the maximum wave height)	day 1, 16:16
Lambton Harbour, Wellington	New Zealand	9,195	0.1		Eyewitness observation of water height
Akazawa	Japan		3		Eyewitness observation of water height
Hamada	Japan		3.9		Eyewitness observation of water height
Hasama	Japan		1.5		Eyewitness observation of water height
Izumisan Region	Japan		2		Eyewitness observation of water height
Kakisaki	Japan		4.6		Eyewitness observation of water height
Kaneta	Japan		3		Eyewitness observation of water height
Kamitaga	Japan		4.5		Eyewitness observation of water height
Kawatsu	Japan		3		Eyewitness observation of water height
Koke	Japan					day 1, 06:46
Matsuva	Japan		1.5		Eyewitness observation of water height
Sakataru	Japan		3		Eyewitness observation of water height
Shirota	Japan		3.6		Eyewitness observation of water height
Takagami	Japan		1.5		Eyewitness observation of water height
Tsukui	Japan		1.8		Eyewitness observation of water height
Minatomachi	Japan		0.3		Tide gauge (half the maximum wave height)	day 1, 03:51
Yosohama	Japan		0.3		Tide gauge (half the maximum wave height)
Mikita	Japan		0.4		Tide gauge (half the maximum wave height)	day 1, 04:28
Ijiri	Japan		1.5		Eyewitness observation of water height
Miura	Japan		0.2		Eyewitness observation of water height
Nishiura	Japan		1.8		Eyewitness observation of water height
Coast of Shiga	Japan		0.9		Eyewitness observation of water height
Hima Island	Japan				Eyewitness observation of water height
Toyooko	Japan				Eyewitness observation of water height
Yoshihama	Japan				Eyewitness observation of water height

Every tsunami in 1923 The 1900s Tsunamis of Japan The earthquake This day in weather history Alerts 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 1526.