Volcano Watch — There Were Technological Leaps in Volcano Watching, Even 75 Years Ago

In early November, a trek to the summit of the great volcano revealed gas puffing from a cone built during the 1914 eruption and dense fume from the sunken area around it - and a sense of foreboding.

The wait wasn't long. At 5:43 a.m. on Saturday, December 2, 1933, HVO seismographs started recording seismic tremor suggesting that an eruption had begun on Mauna Loa. From a distance, two dense gas plumes could be seen by 7 a.m.; three were visible by 9 a.m. Pele's hair fell on the town of Ho`okena and Honaunau 35 km (22 miles) southwest of the summit. There was no sign of lava outside the rim of Moku`aweoweo caldera.

At the start of the eruption, whatever could be witnessed from settled areas mostly near the coast was all that was known to the world. Mauna Loa was "staging a spectacle for the gods," as the Honolulu Advertiser reported, because there were no mortals to witness its beginning.

That was soon to change, because volcano watching had been significantly upgraded since Mauna Loa last erupted 7 years earlier.

Word of the eruption quickly reached Lorrin Thurston of the Honolulu Advertiser and Stan Kennedy of Inter-Island Airways, the predecessor to Hawaiian Airlines, via the newly developed radio-telephone early that morning. They hatched a plan.

Inter-Island Airways, then in operation for only 4 years, scheduled the first-ever Hawai`i volcano-watching flight for 11 a.m. from Rodgers field outside Honolulu. On board were Kennedy, 2 Advertiser reporters, a Naval photographer, and 5 other lucky souls. The flight took nearly 3 hours in a Sikorsky S38 amphibian plane, but the weather was clear and, upon arrival, the views were fantastic.

A second flight started from Hilo at about the same time with National Park superintendent Wingate aboard. Thomas Jaggar, who was not a fan of flying, left for the summit, as he always had, by horse.

A few minutes after the planes became airborne, three Army privates arrived at the crater rim on foot. They had been awakened at the Rest House at 10,000' elevation by the early morning earthquakes accompanying the eruption. They later described seeing 12 fountains along a 3-km-(2 miles) long fissure producing lava flows that covered half the floor of Moku`aweoweo Crater.

What they couldn't see was lava cascading from the fissure into two smaller pit craters to the south of Moku`aweoweo, but this scene awed the Inter-Island plane passengers. One of the reporters described it as a "Niagara Falls of white hot lava pouring furiously into the crater over the southwest rim from a vent just above the edge."

As the eruption progressed, hundreds more airline passengers witnessed the changes first-hand. After these tour flights, more than one reporter broadcast their descriptions over local radio stations to an eager audience. Many sturdy residents also made the trip on foot and horseback with the help of guides from Kīlauea Military Camp and Hawai`i National Park (as it was known then).

A week after the eruption started, a phone line to the Pu`u `Ula`ula Resthouse, installed the previous summer, was extended to the summit by Army and Park Service volunteers. For the first time, a Mauna Loa summit eruption was described live from the crater floor over radio station KGU.

The eruption lasted 18 days, and lava never left the crater. Jaggar did eventually take a reconnaissance flight. He recognized the advantages of aerial reconnaissance right away: "? this was the first time in the history of Mauna Loa when its summit eruption was repeatedly so inspected, by regular passenger planes. By this method far more could be determined in a few minutes, concerning the progress of the eruption, exploring from an airport (65 km or 40 miles) away, than through days and weeks of camping trips, wherein only a small part of the field could be seen at one time."

Seventy-five years later, amphibian propeller planes and wired telephones have been replaced by turbo-jet helicopters, webcams, and cell phones. But the air tour business will continue to thrive as long as Hawai`i volcanoes continue to erupt.

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Volcano Activity Update

Kīlauea Volcano continues to be active. A vent in Halema`uma`u Crater is emitting elevated amounts of sulfur dioxide gas and has resumed producing small amounts of ash. Resulting high concentrations of sulfur dioxide in downwind air have closed the south part of Kīlauea caldera and produced occasional air quality alerts in more distant areas, such as Pahala and communities adjacent to Hawai`i Volcanoes National Park, during kona wind periods. An increase in glow, gas-rushing sounds, and ash production over the past week indicates that lava may have risen to a shallower level beneath the vent.

Pu`u `Ō`ō continues to produce sulfur dioxide at even higher rates than the vent in Halema`uma`u Crater. Trade winds tend to pool these emissions along the West Hawai`i coast, while Kona winds blow these emissions into communities to the north, such as Mountain View, Volcano, and Hilo.

Lava erupting from the Thanksgiving Eve Breakout (TEB) vent at the eastern base of Pu`u `O`o continues to flow to the ocean at Waikupanaha through a well-established lava tube. Breakouts from a western branch of the lava tube were active on the coastal plain near the National Park boundary in the past week and reached the ocean late on January 21 or early January 22. This tiny, new ocean entry is located very close to the long-buried Waha`ula Heiau and National Park visitor center.

Be aware that active lava deltas can collapse at any time, potentially generating large explosions. This may be especially true during times of rapidly changing lava supply conditions. The Waikupanaha delta has collapsed many times over the last several months, with three of the collapses resulting in rock blasts that tossed television-sized rocks up onto the sea-cliff and threw fist-sized rocks more than 200 yards inland.

Do not approach the ocean entry or venture onto the lava deltas. Even the intervening beaches are susceptible to large waves generated during delta collapse; avoid these beaches. In addition, steam plumes rising from ocean entries are highly acidic and laced with glass particles. Call Hawai`i County Civil Defense at 961-8093 for viewing hours.

Mauna Loa is not erupting. Two earthquakes were located beneath the summit this past week. Continuing extension between locations spanning the summit indicates slow inflation of the volcano, combined with slow eastward slippage of its east flank.

Two earthquakes beneath Hawai`i Island were reported felt within the past week. A magnitude-3.9 earthquake occurred at 2:55 a.m., H.s.t., on Sunday, January 17, 2009, and was located 9 km (5 miles) south and offshore of Kalapana at a depth of 42 km (26 miles). A magnitude-3.1 earthquake occurred at 6:23 a.m. on Thursday, January 22, and was located 11 km (7 miles) southeast of Waiki`i at a depth of 11 km (7 miles).

Visit our Web site for daily Kīlauea eruption updates, a summary of volcanic events over the past year, and nearly real-time Hawai`i earthquake information. Kīlauea daily update summaries are also available by phone at (808) 967-8862. Questions can be emailed to askHVO@usgs.gov. skip past bottom navigational bar