Hawaii’s largest island and its residents were rattled by an earthquake at approximately 2:18 AM overnight on Sunday morning. The tremor registered a rating of 4.5 in magnitude, awakening many residents who called local law officials overnight. The epicenter was about five miles north of Naalehu and about six miles below the surface. Earthquakes are fairly common on a local fault plane between the ocean floor and the volcanic crust lying above it. This also created several low-intensity aftershocks of less than a magnitude of 2.0 in the morning hours afterward. There have been no reports of structural damage in the area or loss of life, with just shaken lights as the main problem.
In the previous 30 years, this northern area close to Naalehu has suffered six tremors of more than 4.0 in severity. The Ka’u region is a place where seismic activity is fairly common. A quake that registered 6.2 in intensity occurred almost a century ago in 1919. Going back to 1868, Hawaiian area tremors have seen magnitudes of anywhere from 6.0 to 7.9.
This weekend is far from the first earthquake to rattle Hawaiian residents. The history of Hawaii and its tremors is extensive, dating back to the 1830’s and the chronicles of Mrs. Sarah J. Lyman, the wife of a missionary residing on the big island in the town of Hilo. Her journals spanned over 50 years until her death in 1885, then carried on by family members until the dawn of the 20th century.
There are several active volcanos in Hawaii, so a common fear among the locals is the tremor triggering a volcanic eruption. In the area’s greatest quake of 1868, there were literally hundreds of shocks felt in the week leading up to the main quake on April 4th, which was estimated to have a 7.75 magnitude. At Kona, there were approximately 2000 tremors recorded over a two-week period beginning Mar. 28, 1868. During the main earthquake, landslides that lasted for over three miles caused the death of over 30 people and thousands of heads of livestock. This quake triggered a tsunami that killed 62 people at Keauhou, Puna, and Honuapo. Reaching heights up to 10 feet high, this wave carried inland hundreds of feet, wiping away almost 200 houses in the process.
Another major earthquake was registered on August 21, 1951, producing a top intensity of 9.0 with the magnitude of 6.9. Along the Kona coast, on the west side of Hawaii, many homes were damaged or destroyed. Landslides and falling rocks generated massive waves of up to 12 feet. One landslide managed to consume the Pali Kapu o Keoua burial grounds, members of the Hawaiian royalty. Highway roads saw damage that caused rifts of up to six inches wide. Phone and utility service were lost throughout the region. Collapsing water tanks at Kona’s coastal region required water to be shipped in from Hilo for a two-month period during their dry season.
Tsunamis are a common by-product of the massive underground tremors, many times causing more damage than the earthquake itself. Hawaii saw the worst tsunami in its history on April 1, 1946 following a tremor at the Aleutian Islands. This tremor produced waves of over 50 feet in height on the northeastern coast. At Hilo alone, 173 people were killed and hundreds of homes were destroyed. The event triggered the Tsunami Warning System, which serves not just Hawaii but nations throughout the region. It provides a safety net of notification for when such disaster may strike, giving officials time to evacuate residents.
Fortunately, the earthquake in Hawaii this weekend only rattled the lights of residents overnight and saw a few minor aftershocks. Hawaiian earthquakes have a history of doing much more. Hopefully, this will be the last of any such issues in the near future, and the residents can sleep soundly going forward.
By Evander Smart
Photo by Ricardo Mangual – Creativecommons Flickr License