Wednesday, December 15, 2004

Earthquake History of Hawaii

Earthquake History of Hawaii - Much of the early record of Hawaiian earthquakes comes from the diary of Mrs. Sarah J. Lyman, a missionary's wife at Hilo, on the Big Island of Hawaii. She began her account in 1833 and continued it until her death in 1885. This record was then continued for eleven more years by her descendants.

From the site:

On February 19, 1834, a strong shock threw down stone walls, stopped clocks, upset bottles, and sloshed milk out of half-full pans. Standing and walking were rendered difficult. A similar earthquake occurred on December 12, 1838. No volcanic activity was noted for either event.

On March 27, 1868, whaling ships at Kawaihae on the west coast of Hawaii observed dense clouds of smoke rising from Mauna Loa's crater, Mokuaweoweo, to a height of several miles and reflecting the bright light from the lava pit. Slight shocks were felt at Kona on the west coast and Kau on the flanks of the volcano. On the 28th, lava broke out on the southwest flank and created a 15-mile flow to the sea. Over 300 strong shocks were felt at Kau and 50 to 60 were felt at Kona. At Kilauea the surface of the ground quivered for days with frequent vigorous shocks that caused lamps, crockery, and chairs to spin around as if animated. One shock resembled that of a cannon projectile striking the ground under the proprietor's bed, causing him to flee, according to the narrative published by C. H. Hitchcock in the Bulletin of the Seismological Society of America in 1912. Between March 28, 1868, and April 11, over 2000 distinct shocks were felt at Kona.

The main shocks struck on April 2, at 4:00 p.m., and again on April 4 at 12:30 a.m. A magnitude of 7 3/4 was estimated for this earthquake (by Augustine Furumoto in his February 1966 article on the Seismicity of Hawaii in the Bulletin of the Seismological Society of America) based on the extent of intensity reports. Instrumental recordings, the usual basis for computing magnitudes, were not available at this early date. The shock was felt throughout the islands as far as Niihau some 350 miles away. The ground rolled like a ship at sea and many walls tumbled down. A landslide three miles long and thirty feet thick swept down the hill carrying trees, animals, and men. Thirty-one people and thousands of cattle, sheep, horses, and goats were killed in the one slide. A seawave struck the coast from Hilo to South Cape, being most destructive at Keauhou, Puna, and Honuapo; 180 houses were washed away, and 62 lives were lost to the wave alone. A 10-foot-high wave carried wreckage inland 800 feet. Not a house survived at Honuapo. A stone church and other buildings were destroyed at Punaluu. Maximum wave heights were 65 feet, the highest observed on Hawaii to date.

1 comment:

E. Powers said...

This earthquake on the Big Island has really got me worried. I was in a 6.1 earthquake in L.A. in the mid '80s and it was pretty bad, but this one was .5 worse. It seems to me to be a safe bet that there will probably be more rather than fewer Hawaiian earthquakes in the near future, so I'm thinking the time to get out is NOW while the getting is good and property values are still high.