Hawaiian Volcano 


T.A. Jaggar did not confine his efforts to Kilauea; he had a sustained interest in the equally active volcano of Mauna Loa and spent much time and energy attempting to obtain improved access to it. The following account is mainly compiled from various issues of the HVO Bulletin from the years 1913-17, 1920, and 1922.


In late November 1914, during a summit eruption of Manna Loa, Jaggar attempted to view the lava fountains but failed. His mounted expedition was driven back by a severe wind and snow storm near the summit; they were even forced to abandon the camp equipment. From that time on, Jaggar advocated a shelter on the summit for men and horses and for the safe storage of instruments. To reach the summit, Jaggar wanted at least a horse trail (a road for vehicles would be better) from HVO headquarters at Kilauea. This meant the trail or road would ascend the northeast rift of Mauna Loa; overnight facilities would be needed along the trail. Early in 1915, Jaggar told the HVRA that Mauna Loa was a desert waste without water. Expeditions to the summit were exhausting, and animals employed frequently had their legs cut by the rough lava; consequently, ranchers would not rent good animals. There was no shelter on the summit, little water, no feed, violent winds, and low temperatures. It cost several hundred dollars to make a trip to the summit, and one generally had to return before any real scientific work could be done.

Through 1916, the Ainapo Trail over jagged aa and thin-crusted pahoehoe lava fields was the customary route to the summit of Mauna Loa (Apple, 1973). Until horses and mules became cheap and plentiful, an arduous hike of several days' duration up this trail was the most practical way to the summit. Most of the trail lay on the Kapapala Ranch, and Kapapala cowboys were hired as guides and packers. The Ainapo was about 54 km (34 mi) long and rose from 600 m (2,000 ft) to 4,000 m (13,000 ft) above sea level. The lower trailhead was the village of Kapapala. It was by way of the Ainapo Trail that Jaggar first visited the summit caldera in September 1913.

The surface of the Ainapo Trail was rugged, and it was not maintained for either men or mounts. Jaggar wanted a "simple route to the summit" to give scientists and the public access; with Thurston's help, he got the U.S. Army to build one in the fall of 1915.

Seismologist H.O. Wood, guide Alex Lancaster, and J.E. Haworth made a preliminary survey of a trail from Kilauea up the northeast flank of Mauna Loa to the summit in August 1915. Jaggar, Thurston, and a Lt. Philoon, 25th Infantry, U.S. Army, checked it in September. Thurston and his friends had received the approval of the departmental commander for the U.S. Army to build the trail Jaggar wanted. The HVRA put up a 5,000-gallon water tank near HVO headquarters to support the Army trail builders, and transported several smaller water tanks up the flank to a camp near timberline, soon called Camp Bates after Capt. Bates, a civil engineering officer. Thirty soldiers, under Lt. Philoon, arrived on October 15, 1915; they were followed two days later by others.

This trail up the northeast flank of Mauna Loa, called the Mauna Loa Trail, was completed in December 1915, and the soldiers were back at Schofield Barracks on Oahu for Christmas. The costs of round-trip transportation for the soldiers by ship, rental of pack animals, and purchase of materials for two buildings were all borne by the HVRA. When Jaggar prepared his proposal for a Hawaii National Park in Washington, D.C., early in 1916, he already had his trail between the summits of Kilauea and Mauna Loa Volcanoes. He hoped to upgrade it to make it suitable for trucks, and he foresaw perpetual Federal maintenance of the route. His bill, when it became law, authorized a strip of land between the summits for such a road, to be surveyed and given legal boundaries at a later date.

When the trail was built in 1915, horses and mules could go as far as Puu Ulaula (Red Hill), a cinder cone at elevation 3,000 m (10,000 ft). As part of the project, the soldiers built a 10-man overnight cabin and a 12-horse stable at Puu Ulaula, 10 hiking miles from the summit. The army cabin, still in use, is called the Red Hill rest house.

HVO hand labor filled cracks with chunks of lava and generally prepared the trail above Puu Ulaula for mounts. The first riding horses and pack mules reached the summit with Jaggar and his assistant Ruy H. Finch on June 29, 1920. Because there were no stable facilities for the animals, the guides, packer, and animals were sent back to the rest house. Jaggar and Finch stayed at the summit; "Jaggar's Cave" received its first use that night. (In the same week the first tourists reached the summit over the Mauna Loa Trail; HVRA charged each member a dollar a night at the Red Hill shelter.) In 1930, National Park crews improved the trail for horses.

Until a summit shelter was built by the National Park Service in 1934, hikers and riders were forced to camp in "Jaggar's Cave," a crack in the lava roofed over with corrugated-metal sheets. It was near another crack where water, frozen in winter, accumulated.

Since 1915, in an incremental process, lower portions of the trail have been widened and improved for vehicles. In 1936, the CCC built the last increment, the road from Bird Park to near the site of Camp Bates at elevation 2,025 m (6,650 ft), to permit scientists access by small truck to a seismograph vault near that elevation. The road has since been paved. Most hikers to the summit today start their hike at the upper end of this road.

All during his HVO directorship (1912-1940), Jaggar pressured for a vehicular road from Kilauea up the northeast flank to the summit of Mauna Loa. He wanted the 1915 Army trail improved to allow easy and quick access by HVO vehicles for studies at the summit. Although the National Park Service established boundaries and acquired the strip of land within which the road could be built, it has consistently rejected the concept of a vehicular road to the summit of Mauna Loa. This rejection has been sustained over time, in spite of pressures from Jaggar and Thurston and at times from the Territorial Legislature and the Hawaii County Board of Supervisors. As a result, the road has never been built; the advent of helicopters may now have made moot the question of such a road.

Jaggar's Cave, the 1915 cabin, and the 1915 trail have been declared eligible for listing in the National Register of Historic Places (U.S Department of the Interior, 1973). All are still in use, although the trail has had to be rebuilt in places because of damage from earthquakes and lava flows.


Mauna Loa's recognized eruptive pattern is a summit eruption followed--within hours, days, or months--by a flank eruption. In 1926 there was a brief summit eruption, followed by 14 days of eruption on the southwest rift zone. A flow from this rift zone passed through a South Kona forest, crossed the main road on April 16, and pooled behind the coastal village of Hoopuloa. Between 0400 and 0900 H.s.t. on April 18, the flow buried the village, wharf, and harbor and entered the ocean. This was HVO's first real experience with property destruction by a lava flow. The following account was compiled from Apple and Apple (1979b), Finch (1926), Jaggar (1926a, b), Macdonald and Hubbard (1982), and unpublished sources.

Edward G. Wingate, USGS topographical engineer, was mapping the summit of Mauna Loa in 1926, changing campsites as the work progressed. On April 10 his camp was along the 3,475-m (11,400-ft) elevation, well into the desolate upland above the Kau District. An earthquake wakened the campers about 0145; as they drifted back to sleep, a further series of quakes had them sitting up, talking, and wondering. About 0330 Wingate braved the cold and wind; with a blanket wrapped around him, he went outside and stood bathed in reddish light.

From his camp Wingate had a wonderful view of smoke columns lighted by the glow from below. They reached the flows about 0630. With his crew, Wingate mapped lava fountains, moving flows, steaming vents, and spewing cones.

The packer who kept Wingate's camps supplied with water, food, and firewood had spent the night on the trail on his way down to pick up another load; he reached the Ainapo trailhead midafternoon on April 11. More than supplies awaited him--there was an HVO expedition demanding guide service to Wingate's camp. This was the first news of the eruption for the packer. The expedition consisted of Jaggar, topographer J.C. Beam, cook H. Yasunaka, and packers John Kama and Joe Kaipaloa.

After a night at Ainapo, and with three additional pack animals borrowed from Kapapala Ranch, the expedition started up toward Wingate's camp. By midafternoon they reached the camp, which Jaggar described as a primitive affair consisting of three tents and a cook shelter on the rough lava fields. The cook shelter was bolstered with stone walls to protect against wind, but all the tents had to be tacked down to the pahoehoe lava with spike nails.

For three days the HVO party surveyed the sources of the eruption; then they descended and moved into Kona District, where roads, houses, and other property were threatened by the flows. Wingate and his crew stayed behind. Much of the area already mapped was under fresh lava, and there was a lot of remapping to do.

On April 16, Tom Jaggar scratched marks about a foot apart across the rutted, gravel road (the only road) between the Kona and Kau Districts. A lava flow was approaching, and Jaggar wanted to measure the flow's speed as it crossed the road. Perhaps a hundred people were waiting around the Hoopuloa Church, on the uphill side of the road, and at the Kanaana house opposite, on the downhill side of the road. They had seen and heard the flow, 4.5-6 m (15-20 ft) high and more than 150 m (500 ft) wide, as it moved through the forest uphill. When it neared the road, people who lived on the Kona side of the flow moved off to the north, and those who lived on the Kau side moved to the south, so they could go home after the road was closed.

Jaggar recorded that it reached the uphill, inland side of the road at 1222 at an estimated speed of about 2 m/min (7 ft/min); within two minutes the road was crossed. Jaggar and his assistant, H.S. Palmer, stayed on the Kau side. Soon Robinson MacWayne, Honomalino Ranch proprieter, supplied horses, ranch hands, and guide service through coastal Milolii to Hoopuloa. Jaggar and Palmer set up camp in the Hoopuloa store. Jaggar noted that the Chinese proprietor had swept the building spotlessly clean after removing his stock of goods and furniture. Both the store and the adjacent wharf lay directly in the track of the oncoming lava front. Groups of people were huddled along the stone walls back of the village, watching the glowing, crunching, relentless wall of fire behind, but watching it at leisure, without excitement, and with great weariness because the main event had been postponed. All had come to see the lava enter the sea, but it was still several hundred feet away.

Those watching parked their cars on the Kona side of Hoopuloa. One enterprising youth used his small truck to haul water from the Hoopuloa tanks to Milolii, the end of the road. When the flow reached the sea, he and his truck were cut off; he later took his truck apart and transported it piece by piece by outrigger canoe to the road on the Kona side of Hoopuloa. At about 0300 H.s.t. April 18, the flow rode over the stone walls behind the village and started burning outhouses. Pigs heard squealing in a pen were released. Destruction of the village was gradual and complete. As soon as lava began falling into the sea, steam shot up in jets. Hundreds of dead fish floated along the edge of the turbulent water that spread out from the contact area of hot rock and cold ocean. Hawaiians from Milolii came in their canoes and gathered the dead fish for salting and preserving. Jaggar collected some dead, floating fish and noted that they were perfectly fresh and in no sense cooked.


Many observers have noted that barriers, both natural and manmade, can sometimes stop, divert, or delay the forward movement of a lava front. The worried people of Hilo in 1881 first considered the use of explosives to stop a flow that threatened their port and homes; this is the earliest recorded suggestion for such action in Hawaii (Lockwood and Torgerson, 1980). The concept of using explosives to modify the forward motion of a lava flow was advocated by the HVRA's Thurston in his newspaper in 1929. Tom Jaggar and Ruy Finch of HVO were actively involved in using explosives in the form of aerial bombs on moving lava flows that threatened Hilo in 1935 and 1942, respectively. Bombing the upper reaches of a lava tube feeding a Mauna Loa pahoehoe flow in 1935 is credited with slowing or stopping the advance of the distal end; the 1942 bombing breached the levee of an aa flow and was also partly successful in slowing the flow's advance (Bolt and others, 1975).

In 1937 Jaggar proposed construction of a comprehensive set of embankments, 5-6 m high, to divert Manna Loa lava flows from Hilo town and its harbor; the embankments would have had a total length of about 20 km (including 11 km in a single wall around the south side of the town) and were projected to cost about $800,000 (Jaggar, 1937). These barriers have yet to be built, though experience elsewhere shows that they could be effective (Bolt and others, 1975). Jaggar's interest in controlling lava flows to protect property continued long after his retirement from HVO (see Jaggar, 1945).



PIONEERING, 1912-1953









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