My experiments with volcanoes

by Thomas Augustus Jaggar

Richmond Hodges, sent by the Geological Survey from Washington, was trained in the technique of government filing and relieved me of work with correspondence and routine. He also took over the editing of the Volcano Letter and assisted Mr. Wilson with the writing of articles when I was away in Alaska. My secretaries after Hodges were Ruth Baker and Sutejiro Sato, and Miss Baker’s work extended into the 1940’s.

Tilt studies made at the three cellars around the rim of Halemaumau did not produce the anticipated results, but they answered our questions. The three cellars were placed at 120 degrees to each other, with reference to a meridian crossing the pit, one at the north, one east-southeast and one west-southwest.

It was thought, when these tiltoscopes were set up, that the Kilauea floor would swell or shrink as an inner dome, with the pit at its center. But nothing of the kind was revealed. The tilting was found to be more or less at right angles to the long western wall of Kilauea Crater, itself an extension from the southwestern rift of Kilauea Mountain. The rift extends under Halemaumau pit, as was proved in 1920, when the Kau Desert outflows from the rift cracks kept pace with the lowering of Halemaumau lava. This means that the ring of Halemaumau’s rock wall is in two pieces, divided by the rift dikes trending northeast-southwest, and that the tilting over upward pressure from below is not radial but is northwest and southeast. Wilson’s leveling results that showed the whole mountain swelling up were based on isolated benchmarks relative to sea level, and this swelling was probably unsymmetrical, just as the southwest rift and the eastern rift of the Chain of Craters make a bend in plan and are unsymmetrical. The mountain is not a uniform elliptical dome.

I have said that the decade of the 1930’s was a time of culmination for Kilauea. It was also a period of financial depression and stress for all of us. The Volcano House burned down, the new hotel was placed on the Observatory site, and the Observatory administration barely survived. The Hawaiian Volcano Research Association did much to keep the Observatory alive, but one year we all went on half pay. By dint of this half-pay episode and because everybody insisted that volcano records must not be permitted to lapse, the Secretary of the Interior transferred the Observatory in 1935 to the better financed National Park Service.

With Wingate as superintendent of Hawaii National Park, we were assured of loyal support and were able to combine scientific aims with National Park activities. Thus, the Volcano Observatory regained its status. We were also assisted by the publication of the economic success of the Mauna Loa bombing, in face of the threat to Hilo which involved some 51 million dollars of buildings and harbor. This threat Wingate and I studied carefully in the light of history, and we succeeded in getting $10,000 from Congress for an investigation by U.S. Engineers of the possibility of a construction to protect Hilo from a disastrous lava flow. Colonel Bermel appointed civil engineer Belcher to Hilo, and Belcher worked for a year in 1938 on my design of a lava diversion channel and earthworks, to extend for seven miles from the Wailuku River gorge above Hilo to the airport.

This was to take care of another such lava flow as that of 1881 by deflecting it with the natural valleys southward from the congested district. A critical design was made of the channel, the height of the obstruction, and the openings needed for waterways and public roads. The plan was not to block the passage of lava, but merely to deflect it by means of an artificial barrier to channel it downhill. This would send it along the natural grades, diagonally forcing a lava stream away from the business district, the harbor, the factories, and the airport.

The design was approved by a reviewing board in Washington as effective for the purpose intended. However, with this project went a redesign of Hilo breakwater and a plan for dredging the harbor which took into consideration the possibility of a severe tidal wave. Unfortunately the appropriation estimate was considered too large and was turned down in Washington. When the great tidal wave came in 1946 it proved that such an extended breakwater attached to the northern shore of Hilo harbor would have lessened the terrible destruction and loss of life.

A diversion in the lives of Mrs. Jaggar and myself was an invitation in 1936 from the Royal Society of London, to go to Montserrat in the West Indies where for three years they had been having bad earthquakes. Sir Gerald Lenox-Conyngham, whom we had met at the Japan congress, wrote me asking for my help because Montserrat’s dormant hot volcano was making excessive hydrogen sulfide gas at its two solfataras. The smell sickened and alarmed the inhabitants of the port of Plymouth, and the gas was blackening the paint of white steamships. The earthquakes had come in spasms culminating in big damage to masonry from 1934 onward. Perret had flown over from Martinique and tried to help by applying sound theories to prediction of seasonal tidal controls of the volcano, but he was scoffed at as a voodoo soothsayer by a British Navy captain. The scientific commission appointed was Dr. C. F. Powell of Bristol, now Nobel Prize physicist, and Dr. A. G. MacGregor of the Geological Survey, besides Dr. Lenox-Conyngham, formerly Director of the Geodetic Survey of India. Dr. Powell used adaptations of my shock recorder, both horizontal and vertical, built by the Kew Observatory. Designs had been obtained from instruments I sent to Dr. Marsden in New Zealand, after the Napier earthquake.

When I received the invitation to go to Montserrat, I packed up such instruments as I could find, and telephoned Mrs. Jaggar in Honolulu to be ready to go with me to Los Angeles the following Saturday. She was always ready to act as secretary on a new adventure, and with much bustle and scramble we packed her things. Later I joined her at the steamer, a Danish freighter which was to take us through the Canal to the Caribbean. Boarding as we did on such short notice, we were given a steward’s room in the bowels of the ship; but we had the run of the first cabin. It was a delightful trip through Panama and Jamaica, both of which I was happy to see again, twenty-six years after my 1910 experience with the canal engineers. Great changes had been wrought, and it was a thrill to see the ship pulled through step-up after step-up of canal locks, by the “iron mules” of that marvelous machinery.

We left the delightful freighter people at Charlotte Amalie in the Virgin Islands where we stayed at Blue Beard’s Castle. After a wait of some days, we got a small Dutch island freighter to go to Montserrat. We stopped at St. Martin, an astonishing place, French at one end and Dutch at the other, with practically no custom house to mark the boundary, though the wines and the language changed in the middle of the island.