Historical tsunamis · Dec 9, 1909, 11:28 PM UTC
1909 Guam, Mariana Islands tsunami
USA Territory
The tsunami of Dec 9, 1909, 11:28 PM UTC originated near Guam, Mariana Islands (USA Territory).
Key facts
- Date
- Dec 9, 1909, 11:28 PM UTC
- Cause
- Earthquake
- Magnitude
- M8.0
- Depth
- 100 km
- Maximum documented water height
- —
- Damage
- moderate (about US$ 1–5 million)
- Observation records
- 1
- Countries affected
- 1
It was triggered by a magnitude 8.0 earthquake at a depth of 100 km.
1 observation sites in 1 countries are recorded.
Damage is estimated at moderate (about US$ 1–5 million).
Map of observation sites
1Each dot is a documented observation site; colour and size show the observed water height. The triangle marks the source.
Observations by country
| Country | Observation records | Maximum documented water height | Deaths | Earliest arrival |
|---|---|---|---|---|
| USA Territory | 1 | — | — | — |
Highest documented water heights
1 / 1Individual documented observations for this event. Heights come from different measurement types and sources; not every location has a measured height.
| Location / station | Observed height | Distance from source | Country |
|---|---|---|---|
| Agana Harbor, Guam · Gu | — | 112 km | USA Territory |
Source: NOAA National Centers for Environmental Information (NCEI), Global Historical Tsunami Database. Confirmed events only. Deaths and damage are database estimates; older records are incomplete. Water heights come from different types of observation.