Volcano Watch — Eyewitness accounts tell terror of huge quake in 1868

Residents of Pahala felt a small earthquake (magnitude 3.7) at 10:22 p.m. on September 10. This earthquake was located a few miles northwest of the town and about 6 miles deep. Although the earthquake caused no damage, this was the site of the largest historic earthquake in Hawaii, which occurred in 1868. The eyewitness accounts of this earthquake are colorfully written, as well as awe-inspiring, but serve to teach us what the worst-case scenario for earthquakes might be in Hawai`i. The worst-case is the case we should be prepared to face.

Perhaps the best account comes from a letter by Frederick Lyman to his cousin Jose. He writes, " . . . we were living at the time of the great earthquake on our stock farm, in Ka`u 30 miles southwest of the volcano, at the foot of Mauna Loa some 4 or 5 miles from the sea shore. About sunrise Friday morning, March 26 (this date is incorrect; it was the 27th), the boys who were milking the cows called out 'see the fire on the mountain'—we saw a column of thick smoke (fume) rising rapidly on the top of the mountain, and soon a second column, a little south of the first, and then a third, and a fourth column. Between 9 and 10 o'clock, a slight tremble, soon another, and another, at short intervals. Bella tried to keep a record of them, but soon gave it up, when they went into the hundreds during the day—some of them harder, and continued through the night. Saturday morning, when the clouds cleared away, we . . . only saw black lava, and columns of smoke rising further South than the day before, and so it went on day after day, further South, with more earthquakes, increasing in violence. On Saturday, just after lunch, there was a hard one, peculiar, it seemed as if we moved backwards and forwards, 2 or 3 feet each time, for several seconds—it made the small children seasick—and it threw down some of our stone walls. We had to keep up with our usual duties - but the earthquakes kept on too - every few minutes, often we could hear it coming from the south, then give us a good smart shake and pass on towards Kīlauea, North East from us—at night it made the house rock and creak like a ship in a heavy sea, and we could not sleep . . ."

T.M. Coan, in an article for Scribner's Weekly in 1871, wrote that "For four days this state of things continued, until at 4 p.m. on the 2nd of April, 1868, an event occurred which defies description. "Such a convulsion has no parallel in the memory, the history, or the traditions of the Hawaiian Islands. The shock was awful. The crust of the earth rose and sunk like the sea in a storm. The rending of rocks, the shattering of buildings, the crash of furniture, glass, and earthenware, the falling of walls and chimneys, the swaying of trees, the trembling of shrubs, the fright of men and animals, made throughout the southern half of Hawaii such scenes of terror as had never been witnessed before. The streams ran mud, the earth was rent in thousands of places; and the very streets of Hilo cracked open. Horses and their riders were thrown to the ground; and multitudes of people were prostrated (thrown to the ground) by the shocks. In the district of Ka`u more than three hundred shocks were counted upon this terrible day; people were made seasick by their frequency. By the culminating shock, nearly every stone wall and house in Ka`u was demolished in an instant." Mr. Frederick Lyman wrote "about 4 o'clock it shook as usual, but did not stop—shook East and West, North and South, round and round, and up and down—lessen, then increase in violence." Mr. Coan continues the description embellishing Mr. Lyman's letter: "It was impossible to stand; we had to sit on the ground, bracing with hands and feet to keep from rolling over. In the midst of it we saw burst out from the mountain, about a mile and a half to the north of us, what we supposed to be an immense river of molten lava (it was actually an avalanche of red earth) which rushed down its headlong course across the plain below, apparently bursting up from the ground, and throwing rocks high in the air, and swallowing up everything in its way—trees, houses, cattle, horses, goats, and men. It went three miles in less than three minutes' time." What Mr. Lyman and Mr. Coan have described so vividly at the end of this passage is a landslide in Wood Valley triggered by the earthquake.

Just after the hard shaking had ceased, Mr. Lyman writes, " . . . all along the coast it (the sea) was surging and boiling furiously. Tidal waves (tsunami) . . . wiped out the villages along the coast, 75 people swallowed up in it."

The aftershocks from the great earthquake apparently continued for about one year, for Mr. Lyman writes, " . . . and there were no more severe shakes; they gradually diminished, and in a year from the start were all over and quiet again." He ended his letter with the comment that they did not return to Ka`u to live, as the nervous strain was too much for his wife and children. In addition, many of the Hawaiians who left remained in Hilo or elsewhere.

From the large area where damage from this earthquake occurred, seismologists have estimated that the main shock had a magnitude of about 8. This is probably as large as earthquakes can get in Hawai`i, although this is little comfort, considering the vivid descriptions of this great earthquake. Fortunately, such events do not occur frequently in Hawai`i, but these descriptions serve as a reminder of what can occur here. The events of 1868 suggest that great earthquakes may be triggered by large eruptions of Mauna Loa and that these large earthquakes can, in turn, cause large tsunami.

Volcano Activity Update

In addition to the magnitude 3.7 earthquake near the site of the great earthquake of 1868, two other earthquakes were felt in the last two weeks. The first occurred at 10:28 p.m. on September 3 and was located in the Ka`oiki fault zone between Kīlauea and Mauna Loa Volcanoes. It was seven miles deep and had a magnitude of 3.2. The other occurred beneath the south Kona coast at 9:02 p.m. on September 14, was about 9 miles deep and had a magnitude of 3.0.

The eruption along the East Rift Zone of Kīlauea is active, having started up once again a week ago Saturday about 5:00 p.m. Flows are again heading towards the south but have not advanced beyond flows erupted earlier during episode 51. The fume cloud was very vigorous this past week, reflecting more-than-normal steam produced from the heavy rains. The map shows the areas with active flows.