Volcano Watch — Kīlauea: a youngster among world's active volcanoes

Sources/Usage: Public Domain. View Media Details

One of the main impediments to predicting the future behavior of Kīlauea and especially Mauna Loa Volcanoes is the short historical record of each volcano. 

Some other active volcanoes, such as Mt. Etna in Italy, have historical records covering several thousand years. In Hawaii, the historical record is less than 200 years long. 

January 10 is the 150th anniversary of the earliest historical eruption, that of 1843, which we can associate with particular Mauna Loa flows. There were other, earlier eruptions, of course. We know, for example, that Mauna Loa erupted in 1832, because it was observed from Maui by Reverend Joseph Goodrich. However, we have no idea which of Mauna Loa's many "young-looking" flows Goodrich saw. 
Likewise, there are sailing ship's accounts of Mauna Loa eruptions in the late 18th century, but, again, we have no idea which flows were produced. Strangely, there are no recorded Hawaiian legends or oral traditions of Mauna Loa eruptions, either. 
The period of Mauna Loa history recorded by man is very short and begins on January 10, 1843, with the observations of Titus Coan, the celebrated missionary, who was living in Hilo in 1843. The following is his description of what he saw from the window of the Haili Church dormitory: 

"On the morning of January 10th, before day, we discovered a small beacon of fire near the summit of Mauna Loa, directly in the rear of our Station, about thirty miles distant. This was soon found to be a new volcano, bursting out on the northeastern slope of the mountain, at an elevation of nearly 13,000 feet. From this time on the eruption increased in magnitude and intensity, from day to day, till it presented a scene of sublime splendor, disgorging vast columns of fiery fluid which rolled in a broad burning river down the side of the mountain. The rapid disgorgement of the gory flood, the lofty rising of brilliant pillars - like burning brass - the irregular shooting of coruscations, and the fearful flow of the molten sea - all tend to excite a wakeful spirit, and inclined us to keep vigil for most of the night." 

Reverend Coan feared that the 1843 flow would reach Hilo and overwhelm his church, and, in March, became the first Westerner to view Mauna Loa lavas close up - after an arduous, week-long hike up the Wailuku River. He found that the flow's progress toward Hilo was very slow, however. Most of the lava ponded in the saddle between Mauna Loa and Mauna Kea. The eruption ended in mid-April after disgorging about 200 million cubic meters of lava. The 1843 lavas can be viewed in the Humu`ula Saddle, about one mile west of Pu`u Huluhulu, where the saddle road abruptly climbs onto the 50-foot-thick `a`a flow of 1843. The 1843 flow is shown on the map with the subsequent historical flows from Mauna Loa Volcano.

Volcano Activity Update

The eruption at Kīlauea continues after taking a brief pause last Sunday afternoon and night. By Monday morning, lava had reoccupied most of the tube formed during the period of continuous eruption from October 2 to January 3. Numerous surface flows spilled from the tube system from the top of the pali to the new lava bench at the coast, but lava was once again flowing into the ocean by Monday afternoon. 

During the last five weeks, only three earthquakes had magnitudes greater than 3.0. The first, magnitude 3.2, occurred on December 3 at 10:00 a.m. It was located about 47 km (29 miles) beneath Haleakalā Volcano on Maui and was widely felt there. The next two occurred beneath the south flank of Kīlauea and occurred on December 8 at 11:27 a.m. and on January 1 at 9:54 p.m. Both were shallow (less than one-half mile deep) and had similar magnitudes, 3.5 and 3.6, respectively. The earthquake beneath Maui, although small, is the type that can occur beneath any of the Hawaiian Islands; it is caused by the bending of the lithosphere beneath the islands due to their weight. The largest recorded event like this occurred beneath Honomu on April 26, 1973, and had a magnitude of 6.2. This type of earthquake poses the greatest hazard to the islands from Maui to Kaua`i. The two earthquakes beneath Kīlauea are related to instability of the south flank of the island. The largest earthquake of this type in historic times was an estimated magnitude 8.0 and occurred beneath Pahala on April 2, 1868. Such earthquakes pose the greatest seismic hazard to the Island of Hawai`i.