April 11, 2012 Tsunami: Off W. Coast of N Sumatra, Indonesia

Name: April 11, 2012 Tsunami: Off W. Coast of N Sumatra, Indonesia
Start: 2012-04-11
Location: Off W. Coast of N Sumatra, Indonesia

April 11, 2012 · 1.08 m · 10 deaths · Definite tsunami

A tsunami caused by a magnitude 8.6 earthquake began at Off W. Coast of N Sumatra, Indonesia on April 11, 2012 at 08:38:36 UTC. The water rose as high as 1.08 meters. Its effects were recorded at 25 places in at least 11 countries. It killed 10 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

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: April 11, 2012, 08:38:36 UTC
Source: Off W. Coast of N Sumatra, Indonesia
Cause: Earthquake
Earthquake: Magnitude 8.6, 20 km deep
Maximum water height: 1.08 m (3.5 ft)
Runups recorded: 25
Waters: Ocean
How certain: Definite tsunami
Source location: 2.327° N, 93.063° E

The toll

Deaths: 10 with the earthquake or eruption that caused it
Injuries: 12 with the earthquake or eruption that caused it
Damage: Limited (under about $1 million) with the earthquake or eruption that caused it
Houses damaged: Some (about 51 to 100) 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.

A small tsunami was recorded, with maximum wave heights (one-half peak-to-trough) at the following selected tide stations: 1.08 m at Meulaboh, 37 cm at Sabang and 14 cm on Pulau Enganno, Indonesia; 8 cm at Cocos Island, Australia; 23 cm at Chittagong, Bangladesh; 21 cm at Male, Maldives; 17 cm at Port Louis, Mauritius; 11 cm at Trincomalee, Sri Lanka. (reference #1053)

The Wharton Basin, off southwest Sumatra, ruptured to a large intraplate left-lateral strikeslip Mw 7.8 earthquake on 2016 March 2. The epicentre was located ∼800 km to the south of another similar-mechanism intraplate Mw 8.6 earthquake in the same basin on 2012 April 11. Small tsunamis from these strike-slip earthquakes were registered with maximum amplitudes of 0.5−1.5 cm on DARTs and 1−19 cm on tide gauges for the 2016 event, and the respective values of 0.5−6 and 6−40 cm for the 2012 event. (reference #11923)

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	Measured by	First wave, UTC
Meulaboh Port, Sumatra	Indonesia	395	1.08	Tide gauge (half the maximum wave height)	day 11, 09:55
Sabang, Sumatra	Indonesia	463	0.37	Tide gauge (half the maximum wave height)	day 11, 09:42
Campbell Bay, Great Nicobar Is.	India	511	0.3	Tide gauge (half the maximum wave height)
Telukdalam, Sumatra	Indonesia	564	0.24	Tide gauge (half the maximum wave height)	day 11, 09:49
Nancowry Island	India	625	0.12	Tide gauge (half the maximum wave height)
D23327 Bpr, Bay of Bengal	India	643	0.05	Deep ocean gauge (half the maximum wave height)	day 11, 09:17
Ko Taphao Noi	Thailand	849	0.05	Tide gauge (half the maximum wave height)	day 11, 11:33
D23401 Bpr, 600 NM W-Nw of Phuket	Thailand	883	0.05	Deep ocean gauge (half the maximum wave height)	day 11, 09:37
Padang, Sumatra	Indonesia	894	0.09	Tide gauge (half the maximum wave height)	day 11, 10:34
Enggano Island	Indonesia	1,345	0.14	Tide gauge (half the maximum wave height)	day 11, 10:39
Trincomalee	Sri Lanka	1,481	0.11	Tide gauge (half the maximum wave height)	day 11, 11:14
Cocos Island (Keeling)	Australia	1,653	0.08	Tide gauge (half the maximum wave height)	day 11, 10:45
Chennai (Madras)	India	1,842	0.18	Tide gauge (half the maximum wave height)
Ennore	India	1,851	0.09	Tide gauge (half the maximum wave height)
Sittwe	Myanmar	1,972	0.08	Tide gauge (half the maximum wave height)	day 12, 14:22
Visakhapatnam	India	2,004	0.1	Tide gauge (half the maximum wave height)
Male	Maldives	2,182	0.21	Tide gauge (half the maximum wave height)
Chittagong	Bangladesh	2,210	0.23	Tide gauge (half the maximum wave height)	day 12, 06:55
Gan	Maldives	2,241	0.04	Tide gauge (half the maximum wave height)	day 11, 11:19
Hanimaadhoo, Haa Dhaalu	Maldives	2,261	0.23	Tide gauge (half the maximum wave height)	day 11, 11:52
Cape Cuvier	Australia	3,670	0.02	Tide gauge (half the maximum wave height)	day 11, 13:55
Rodrigues Island, Port Mathurin	Mauritius	4,052	0.22	Tide gauge (half the maximum wave height)	day 11, 13:50
Pointe LA Rue, Mahe Island	Seychelles	4,246	0.1	Tide gauge (half the maximum wave height)	day 11, 15:48
Port Louis Harbour	Mauritius	4,610	0.17	Tide gauge (half the maximum wave height)	day 11, 15:14
Reunion	Reunion (French Territory)	4,855	0.05	Tide gauge (half the maximum wave height)	day 11, 15:27

Every tsunami in 2012 The 2000s Tsunamis of Indonesia 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 2026-10-01. NCEI tsunami event 5449.