October 7, 2010
A weekly feature provided by scientists at the Hawaiian Volcano Observatory.
Kīlauea's 1934 eruption: An exciting interlude between years of volcanic quiet
Seventy-six years ago this week—on October 8, 1934—a 33-day-long eruption in Halema`uma`u Crater came to an end. This eruption began after almost three years of quiet at Kīlauea Volcano.
The long period of inactivity from December 1931 to September 1934 was bad news for George Lycurgus, who had repurchased Volcano House in 1932, hoping to fill the 115 hotel rooms with guests eager to see an erupting volcano. With no volcanic activity to attract crowds of sightseers, "Uncle George" claimed he was practically bankrupt by late summer 1934.
With ongoing financial worries, Lycurgus took matters into his own hands on the night of September 5, 1934. A stanch believer in Pele, he and Alec Lancaster, a local guide, trekked out to Halema`uma`u, where they invoked the volcano goddess with prayers and tossed an `ohelo berry lei into the crater. For good measure, Uncle George established his own ritual by also tossing in a bottle of gin—minus the swigs he and Lancaster had taken during their hike—and returned to Volcano House to get some sleep.
A few hours later, at 2:44 a.m., H.s.t., on September 6, lava erupted from the floor of Halema`uma`u—bringing thousands of spectators to the crater rim and patrons to Volcano House. Convinced that Pele had helped him in his time of need, Lycurgus held resolute faith in the volcano goddess for the rest of his life.
Indicators of the 1934 eruption, which included rock slides in Halema`uma`u Crater and southwesterly tilt of Kīlauea's summit, were noted by the Hawaiian Volcano Observatory (HVO) on the afternoon of September 5. Seismic instruments also recorded spasms of volcanic tremor about an hour before the eruption began.
Lava fountains initially erupted at three places within Halema`uma`u Crater. Cascades of incandescent lava surged from a 275-m- (900-foot-) long horizontal crack about half-way up the west wall of Halema`uma`u. Thirty jets of brilliant lava also shot up from the northwest crater floor, sending fragments of pumice (frothy lava) several hundred feet above the crater rim.
Lava flows spreading across the floor of Halema`uma`u coalesced to form a glowing lake that quickly submerged the third—and most northern—line of fountains. Within hours, the entire crater floor was covered by lava 18 m (60 ft) deep.
The vigorous lava fountains generated rumbling sounds that seemed to shake the whole volcano, while the rush of hot gas set in motion hundreds of whirlwinds that swept clouds of pumice and dust up onto the western rim of Halema`uma`u. In the first 12 hours of the eruption, gas fumes rose several thousand feet into the air, filling it with the odor of sulfur dioxide.
The west and northwest fountains ceased within about 12 hours, but the north fountains persisted at the lake's center. In a national radio broadcast from the rim of Halema`uma`u on September 11, HVO geologist Thomas Jaggar described the lava lake as "indescribably beautiful, a vast labyrinth of glowing cobweb pattern ever changing radial and concentric to the central fountain group."
Repeated overflows built a levee around the lake, which eventually shrank in size, forming a small pond atop a terraced heap on the northeast side of the crater floor. Convective circulation developed within the lake, with lava welling up on the west side and draining back on the east.
The north fountains gradually dwindled, but lava continued to erupt beneath the cooling surface of the recently emplaced lava in Halema`uma`u. Consequently, molten lava oozed up in cracks between the crater walls and the crust that covered the crater floor.
As the eruption waned, the lava lake repeatedly drained and filled. Drainage episodes were accompanied by violent bursts of gas, which produced detonations that were heard up to three miles away. After half-an-hour of complete quiet, lava would then stream back in and restore the lake.
Interestingly, the end of the 1934 eruption on October 8 marked the beginning of Kīlauea's longest period of inactivity on record—18 years! When the volcano finally erupted again in 1952, the 93-year-old Lycurgus was there to observe the action—mostly from the comfort of Volcano House, which he still managed—and to pay homage to Pele at the rim of Halema`uma`u Crater.
Kīlauea Activity Update
Lava continues to enter the lava tube system and is carried downslope to Puhi-o-Kalaikini, near Kalapana, where it enters the ocean and creates a large steam plume. Some of this lava was escaping from the tube to form small surface flows that were active near the end of Highway 130, just west of Kalapana, through much of the week. They were joined by a breakout on the pali that was active as of Thursday, October 7. Lava flows were active within the Pu`u `O`o crater through the week, as well, with an increase in lava output on Wednesday that resulted in the formation of a small lava lake on the eastern side of the crater.
At Kīlauea's summit, the circulating lava lake deep in the collapse pit within the floor of Halema`uma`u Crater has been visible via Webcam throughout the past week. The circulation pattern was interrupted sporadically by abrupt increases in the height of the lava surface. These periods of high lava level have been short-lived, lasting up to several hours, and each ended with a sudden drop of the lava surface back to its previous level. Volcanic gas emissions remain elevated, resulting in high concentrations of sulfur dioxide downwind.
One earthquake beneath Hawai`i Island was reported felt during the past week. A magnitude-3.9 earthquake occurred on Sunday, October 3, 2010, at 9:39 a.m., H.s.t., and was located 5 km (3 miles) west of Pahala at a depth of 36 km (22 miles).
Visit our Web site (http://hvo.wr.usgs.gov) for detailed Kīlauea and Mauna Loa activity updates, recent volcano photos, recent earthquakes, and more; call (808) 967-8862 for a Kīlauea activity summary; email questions to askHVO@usgs.gov.
Updated: November 6, 2010 (pnf)