Thomas Jaggar and his wife, Isabel, hiking on Mauna Loa during the September 1919 Southwest Rift Zone eruption. USGS archive photo.

(Volcano Watch is a weekly article written by scientists at the U.S. Geological Survey’s Hawaiian Volcano Observatory.)

After years of fund-raising, Thomas Jaggar, Jr., finally got the Hawaiian Volcano Observatory (HVO) up and running at Kilauea Volcano in January 1912. Within the first year, he had already achieved some significant scientific results, so it seems to us—100 years later—that he must have felt pretty good about those accomplishments.

The collection and analysis of volcanic gas samples was a major focus of Jaggar’s work. On December 4, he oversaw a bold gas sampling descent into Halema`uma`u Crater. At the time, there was an active lava lake in the crater, about 120 m (400 ft) below the crater rim. Dr. E.S. Shepherd, a guest scientist, was still trying to obtain fresh volcanic gas samples before they mixed with air. He had tried to pump gas out of a tumulus in May, only to find that water condensation messed up their sampling scheme.

Their December plan was different. Because the May sampling showed that water was abundant, they were going to take evacuated glass tubes, break the tube seals at the gas vent, and fill the tubes with gas before resealing them. Shepherd, H.O. Wood (Jaggar’s assistant), and long-time guide Alex Lancaster climbed down rope ladders and rubbly slopes to get to the crater floor. They timed their trip to be late in the day hoping to use the darkness to show them where gas was coming out, under pressure, as a jetting flame.

The crater was filled with choking volcanic fume, requiring the use of protective masks. Alex led the way to the fumaroles and made sure everyone got out safely. Jaggar handled all ropes for the descent but remained at the rim to oversee the experiment’s progress and, probably, to be a lookout for any hazardous changes to the conditions in the crater.

The gas samples were still not optimum for the desired analyses, but Shepherd and his colleague published their findings the following year, concluding that “… water released from the liquid lava when it reaches the surface is entitled to be considered an original component of the lava with as much right as the sulphur or the carbon.”

Despite these findings and others obtained later, Thomas Jaggar never accepted the conclusion that water was an original component of volcanic gas. So while this early scientific result was hailed as an early proof of his HVO concept, he himself didn’t believe the answer.

Thomas Jaggar wrote many scientific and philosophical papers, but he wrote very little about his personal life. When he came to Kilauea Volcano in January 1912, his wife, son, and baby daughter remained in Boston. In March, Jaggar received an urgent message from his wife to return to Boston because of his children’s health, and he hastily left Hawai`i. But he returned to Kilauea in July, again without his family, to resume stewardship of HVO.

In those days, inter-island travel was done by boat, and lists of passengers were published in the Honolulu newspapers. It is through these old newspapers that we know of a visit to Hawai`i by Mrs. Jaggar, her two children, and a maid. They arrived in Honolulu in late November and stayed at the Pleasanton Hotel near Punahou School in the Makiki District. Jaggar had hoped that his son, Kline, would attend school in Honolulu. Jaggar was in Honolulu to greet his family and brought them to Kilauea Volcano and his life’s work just before the December gas sampling experiment.

Sadly, Jaggar’s private life didn’t fare well during his first year at Kilauea. His wife and children left Hawai`i to return to Boston in early 1913, and the couple soon divorced. Then, his father died in December. But Jaggar dove back into work, documenting the lava lake within Halema`uma`u Crater, giving talks about his work, and advocating for a National Park at Kilauea Volcano.

In spite of his rough beginning in Hawai`i, Jaggar achieved success. The Halema`uma`u lava lake was scientifically documented in many reports, and the Park was established in 1916. In 1917, Jaggar married kindred spirit Isabel Maydwell, with whom he continued his interest in Kilauea Volcano until his death in 1953.