November 29, 1975 Earthquake: Hawaii, United States

Name: November 29, 1975 Earthquake: Hawaii, United States
Start: 1975-11-29
Location: Hawaii, United States

November 29, 1975 · M7.7 · 2 deaths · $4 million

A magnitude 7.7 earthquake struck Hawaii, United States on November 29, 1975 at 14:47:40 UTC, 2 km below the surface. It killed 2 people, counting the tsunami it caused.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date: November 29, 1975
Time: 14:47:40 UTC
Place: Hawaii, United States
Magnitude: 7.7 (Mw)
Focal depth: 2 km (1 mi)
Intensity: 9 on the Modified Mercalli scale
Tsunami: Yes: the tsunami it caused
Volcano: The eruption it came with
Epicenter: 19.451° N, 155.033° W
Country: United States

The toll

Deaths: 2 with its tsunami and other effects
Damage: $4 million
Houses destroyed: Many (101 to 1,000) with its tsunami and other effects

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.

Two earthquakes occurred in the morning on Hawaii Island. The first earthquake (3hr 36min local time, 5.1 MS, epicenter near the Kilauea crater) awakened the entire population of the island.

The second earthquake (4hr 48min local time, 7.2 MS, off the southeast coast) caused damage (IX) at Hilo and damage (VIII) at Hawaii Volcanoes National Park. In many places houses were severely damaged, roads were breached and became unusable due to landslides; electric power lines were broken.

Maximum subsidence 3.5 meters along the southeast coast.

Maximum width of ground cracks 1 meter in the park.

There was a brief eruption of the Kilauea Volcano.

The second earthquake generated a locally damaging submarine landslide tsunami that was recorded at tide gauge stations in Alaska, California, Galapagos Islands, Peru, and Chile.

$4 million damage from the earthquake and tsunami. (reference #1053)

1975, Nov. 29. Abstract: The 1975 Kalapana, Hawaii, earthquake occurred under the highly mobile south flank of Kilauea Volcano. It has been interpreted variously as a normal faulting earthquake, a thrust-faulting earthquake, and a landslide. Primary evidence for the landslide model has been the failure of previous faulting models to explain the observed Love-wave radiation pattern and the tsunami amplitudes generated by the Kalapana event. Here, we present a reanalysis of the long-period, digital seismic data for this event. Centroid-moment-tensor analysis shows that the seismic radiation pattern can be explained well by thrust faulting on a plane dipping shallowly landward. The seismic moment of 3.8 X 1020 N m (Mw 7.7) that we determine is approximately twice as large as earlier estimates. The geometry and seismic moment of the focal mechanism determined here are consistent with the observed tsunami amplitudes. Inversion of long-period body-wave waveforms shows that the earthquake source duration (~72 sec) is unusually long for an earthquake of this size. (reference #10818)

1975, Nov. 29 14:47:40.9 UTC. 19.451 N, 155.033 W, depth 2 km, 7.2 Ms, 7.5 Mw. (reference #9910)

1975, Nov. 29 14:47:43.08 UTC. 19.438 N, 155.149 W, depth 10 km, 7.4 Mw. (reference #10476)

Photos

From the NCEI/WDS Natural Hazards Image Database (doi:10.7289/V5154F01). Only photos by the USGS and NOAA, which are public domain, are shown.

Other significant earthquakes nearby

Within 200 km, the deadliest first.

Significant earthquakes of 1975 The 1900s Every quake the USGS located in 1975 Recent earthquakes near here This day in weather history

Sources

Significant earthquakes 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 earthquake 4704.