Writer

Volcano Voice

[Pool, G., 1992, "Volcano Voice," Worldradio, vol. 22, no. 2, August, pp. 11-12.]

When Tom Segalstad, KH6/LA4LN, finally showed up at my office door, he was wet and lost. His first concern, however, was whether his HT was still working after having been in the steady rain falling on Kilauea Volcano.

Tom is a Norwegian geologist who last February was in Hilo on the Big Island of Hawaii for a conference on the interaction between volcanoes and climate. But Tom was not one to wallow in the philosophical ramblings of academia without grounding himself in fact. He wanted to see lava.

After the conference was over, Tom made his way up to the summit of Kilauea, a daunting trip if you expect the topography to reveal the drama of the world’s most active volcano. Kilauea (4,078 feet), like Mauna Loa in its background (13,661 feet), is a low-lying shield volcano that issues forth relatively fluid lavas. These flows often travel many miles, sometimes to be quenched in the blue waters of the tropical Pacific. So Tom, with two days left in paradise and the knowledge that Kilauea is broader than it is high, had a lot of land to cover to feel the heat.

Whetting his appetite, Tom drove down the Chain of Craters Road in the Hawaii Volcanoes National Park to the site of the 1969-1974 Mauna Ulu eruption, the previous record-holder for magma output at Kilauea. On top of an old cinder cone that was once the best spot to view Mauna Ulu’s lava fountains and flows, he spent about an hour gazing 10 miles to the east at the new record-holder.

Since 1983, the combination of lavas erupting from the Pu’u O’o cinder cone and the Kupaianaha lava shield has made 1,900 million cubic yards of mess along Kilauea’s East Rift Zone, four times that of Mauna Ulu. The eruption has also caused the destruction of over 180 homes, including the entire village of Kalapana.

Before Tom arrived, scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory were able to document 51 distinct episodes in the eruption. Just before Tom arrived the 51st has stalled, which at this point was to be expected. Kilauea's three-mile-deep summit magma chamber acts like a post office: It holds the molten rock generated 40 miles beneath the island and then sends it on to the East Rift Zone via a two-mile deep pathway it carved out in 1983. Since that time, Kilauea’s summit has deflated, relatively, because of all the erupted lava. Like a house with low water pressure in its pipes, it’s becoming hard for Kilauea to keep the flow going.

Tom was enjoying the grand irony of weather at Kilauea. At this elevation, the tropical climes longed for on a visit to Hawaii are absent and replaced by an atmosphere more comparable to San Francisco or Seattle. Despite the low clouds and drizzle, Tom stuck it out. His HT gathered moisture and his bones a chill. By chance, just before the clouds obscured the view, he saw fountains shoot out from the western slopes of Pu’u O’o and called me on the local 2M repeater. He had just seen the goddess of the volcano, Pele, awaken. Episode 51 had started up again. His journey was not in vain.

It took a little while for his HT to dry out, but all in all his equipment worked well and it provided the observatory with some good data. His observation correlated well with an increase in harmonic tremor, the seismic signal that indirectly reveals the movement of magma just beneath the surface.

But Tom was still “cold” and needed the warmth of 2000-degree pahoehoe lava to warm him up. Later, after wandering around my office at HVO, we talked about him making the 20-mile round trip hike to the eruption site the next day. This was no easy task, as I knew from personal experience, and I gave him all the warnings necessary when venturing into a wilderness area. He followed them precisely and in the end, barring hardship and more rain, he was the eyes and ears at the site of volcanic upheaval.

A lot of amateurs listened in, too, because he and I used the local 2M repeater (AH6P/R 146.76 kHz) that can be heard throughout the eastern part of the Big Island. A number of hams have asked me about the QSOs and thought it was the most interesting thing heard on radio in a while. Tom provided a big service to a lot of people.

Tom made the four-hour trek out and then called. Never in any real danger, he noted where the new lava flow was going and how fast. He gave us estimates of dimensions and locations that are valuable when trying to piece together the geological history of an episode. We commonly use government radios and frequencies when out in the field, so I passed his observations on to our radio log at HVO.

He was very excited and although he could have melted his HT at one point, he had a good time. The flow was yet another short spurt that would cool when the vent turned off again a few days later. Tom was witnessing a small scale version of Kilauea being built in front of him. Fluid lava had been erupting from a fissure near the western slope of the Pu’u O’o cone and after many weeks, a fan-shaped blanket of cooled lava flows had made a broad and low shield in the middle of rainforest, 2,000 feet above the Pacific Ocean. At this moment, episode 51 continues to erupt in the same manner. To Tom, however, this was the most novel thing he had ever seen. I know exactly how he felt.

Tom was the sole observer for the observatory those two days, mostly because the inclement weather hampered our own efforts to see the eruption site. I’m glad that we had enough in common besides geology to make a friendship and use Amateur Radio for an unusual purpose. When he handed me his QSL card, it was evident that Tom had already been graced with a number of acquaintances from all over the world: He’s held over 20 different calls. I’m sure this wasn’t the first time he’s almost destroyed his HT.