"Mt. St. Helens is a pimple compared to Mauna Loa," said lead scientist Kauahikaua.
Since spring 2002, Mauna Loa has been expanding, indicating that a reservoir of magma is building inside.
Earthquakes close to the surface are common, but scientists continue to puzzle over the hundreds of earthquakes rumbling more than 20 miles below the summit, in the Earth's mantle. These deep earthquakes started the same time the mountain began expanding. As many as 188 have been detected in a single week, most of them small (about magnitude 3) and not felt on the surface.
"This is new, this is unprecedented," Kauahikaua said. "We don't know what it means."
Brenda Domingo has seen what a lava flow can do. A single continuous torrent from Kilauea in 1990 wiped out the village of Kalapana, on the island's eastern shore. About 500 people lost their homes. Domingo and her extended family lost nine houses, including the one in which she and her six siblings were born.
"It was rolling rock, just taking everything, crushing everything," Domingo said.
Hundred-foot hollows in the land were filled like mud puddles. Yet the flow was slow enough that everyone had time to save their precious belongings, in Domingo's case family photos, dishware and traditional Hawaiian floor mats made by her grandmother. A rolling swath of forest burst into flames, and houses burned one after the other. Months would pass before the smoke cleared.
Most of what was Kalapana, a fishing village, is now underneath what looks like a sea of petrified tar, with rivulets and waves hardened in midswirl. The sprouts of giant tree ferns and ohia trees have already begun poking through.
Despite this, Domingo, who lives in a neighboring village, refuses to leave the island. It's home, and she said she could understand why people would want to live here. "It's a beautiful place, and the mountain reminds you life is fragile," she said. "It's sad, but you need to know."
The Rowsells know all about the story of Kalapana. Most residents do; it's part of the continuing legend and enigma of the Big Island.
Walter and Judy have also been hearing the news bulletins about Mauna Loa's strange behaviors. They mostly shrug it off, although it seems to bother Judy some. In one candid moment, she blurted out, "I know we're in denial. We're all in denial on this mountain. But if you're going to be afraid, you have no business living here.... It can happen anywhere."
Judy was alluding to the theory of relative dangers, which is commonly expounded and embraced on the Big Island. The central idea is that no place is completely safe, so why not live here? Southern California has its earthquakes. Florida has hurricanes. The Mississippi Delta has floods.
Hawaii's volcanologists don't want to press their concerns because, after all, they deal in terms of geological time. When they say an eruption is inevitable, it could mean next week or next century. Or next millennium. Civilizations can rise and fall between the clock's ticks. Lives can be lived.
Walter Rowsell concerns himself with a simple practical matter.
"The mountain just needs to hold off for another 10 years. Ten years," he said. "After that, it can do whatever it wants because I won't be here, and I won't care." With that, Rowsell cackles once more, an affectionately defiant laugh, before glancing at his all-gray house and starting off on his daily walk, cane in hand, on the slopes of the world's largest volcano.