Three of Hawaii’s largest recorded earthquakes (triggering tsunami’s) occurred on the Big Island of Hawaii.

Hawaii Earthquakes

1868: The largest recorded earthquake in Hawaiian Island history was the 1868 Hawaii Earthquake which occurred at 4pm HST on April 2, 1868. The quake measured a magnitude of 7.9 on the Richter scale. The quake caused a landslide and tsunami that led to 77 deaths. It is said that the aftershock sequence for this event has continued up to the present day.

A sequence of foreshocks began on March 27, 1868 with tremors every few minutes. Whaling ships at Kawaihae on the Big Island’s west coast observed dense clouds of smoke rising from Mauna Loa’s crater, Mokuaweoweo. Foreshocks increased steadily in intensity, including one on March 28 that had an estimated magnitude of 7.1. Conflicting reports claim March 29 with a 7.0 magnitude. Either way, the sequence continued until 4pm on April 2, when the 7.9 mainshock occurred.

1975: The 1975 Hawaii Earthquake was second largest earthquake and tsunami event recorded in Hawaii, again centered on the Big Island of Hawaii. A 5.9 foreshock occurred at 3:36am on November 29, 1975. Just over an hour later the mainshock hit around 4:48am measuring 7.2 on the Moment magnitude scale. The shock was felt across several of the Hawaiian Islands, even reaching the island of Kauai. This event was notable for the large 47 feet high tsunami triggered by the quake.

Two people were killed and 19 others were injured. Significant damage occurred in the southern part of the Big Island worth $4.1 million from the shaking and the tsunami. The tsunami was also detected as far away as Alaska, California, Japan, Samoa, and on Johnston and Wake Islands. The earthquake also caused significant changes to shorelines along the southern coast of the Big Island. Some areas to be permanently submerged up to 12 feet.

The 1975 quake also triggered a small eruption of Kilauea volcano. The quake itself occurred on the Hilina Slump, which was responsible for the more powerful earthquake and tsunami taking place in 1868.

2006: The 2006 Hawaii Earthquake occurred on Sunday October 15 at 7:07am HST with a moment magnitude of 6.7 and a maximum perceived intensity of VIII (Severe). The shock was centered 13 miles southwest of Puakō and 13 miles north of Kailua-Kona, Hawaii, just offshore of the Kona Airport, at a depth of 18 miles. It produced several aftershocks, including one that measured a magnitude of 6.1 seven minutes after the main shock. The quake did produce a tsunami on the Big Island coast, although the Pacific Tsunami Warning Center measured it 4 inches in height.

Resource & Credit:
Hawaii Style Organization (map)