August 7, 2024 Tsunami: Pedersen Lagoon, AK, United States
A tsunami caused by a landslide began at Pedersen Lagoon, AK, United States on August 7, 2024 at 12:54:49 UTC. The water rose as high as 62 meters. Its effects were recorded at 4 places.
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
The tsunami
- Date
- August 7, 2024, 12:54:49 UTC
- Source
- Pedersen Lagoon, AK, United States
- Cause
- Landslide
- Maximum water height
- 62 m (203.4 ft)
- Runups recorded
- 4
- Waters
- Ocean
- How certain
- Definite tsunami
- Source location
- 59.904° N, 149.825° W
The toll
- Damage
- Limited (under about $1 million)
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 #13830:
A landslide occurred in the early morning on Wednesday, August 7th, 2024, at a latitude/longitude of approximately 59.9038N, 149.8246W, on a southwest-facing slope to the north of Pedersen Glacier. The landslide traveled along the glacier and entered Upper Pedersen Lagoon, producing a local tsunami that traveled across the upper lagoon to Lower Pedersen Lagoon, where it damaged wooden boardwalks in the tidal zone at a lodge and impacted a National Park Service campsite easement.
Preliminary ground-based surveying by the National Park Service indicates that the tsunami was on the order of 17 meters high (approx. 56 ft) on the east side of the upper lagoon, traveled across a portion of the landform between the two lagoons, and reduced to about one meter high (approx. 2-3 feet) in eastern portions of the lower lagoon. The earliest geophysical detections were done by the USGS National Earthquake Information Center and the Alaska Earthquake Center using seismic data, which indicates that the landslide occurred at 04:54:49 AKDT / 12:54:49 UTC. During the tsunami event, seismic signals suggest that a seiche, or an oscillating wave, likely formed.
Preliminary volume estimates based on seismic data1 indicate that the landslide was on the order of 2 million cubic meters
Reference #13831:
An atmospheric river brought intense rainfall to southern Alaska in early August 2024, triggering a large landslide and a tsunami in Pedersen Lagoon.
The wave damaged trees and flattened vegetation between the upper and lower portions of the Pedersen Lagoon. According to local reports, it also damaged a lodge’s boardwalk on the eastern side of the lower lagoon.
Reference #14370:
In 2024 a landslide above Pedersen Glacier fell onto the glacier and slid off the face, generating a very large tsunami. While initial reports cited a 17 m maximum runup, when we surveyed the impacts a month later we found the traces of the wave as high as 62 m above the water. (reference #14369 also lists 62 m)
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 |
|---|---|---|---|---|---|---|---|
| Pedersen Lagoon, AK | United States | 1 | 62 | Runup height, post-tsunami survey | |||
| Upper Pedersen Lagoon, AK | United States | 4 | 17 | Runup height, post-tsunami survey | |||
| Pedersen Lagoon, AK | United States | 5 | 8 | Runup height, post-tsunami survey | |||
| Lower Pedersen Lagoon, AK | United States | 6 | 1 | Runup height, post-tsunami survey |
More
Every tsunami in 2024The 2000sTsunamis of United StatesThis 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 5929.