Volcanoes, Earthquakes and Crocodiles

Courtesy of OSPA

by David Bell (Geologist, British Solomon Islands Protectorate (BSIP) 1959-61)
Volcanoes, Earthquakes and Crocodiles
Tinakula Volcano
After finishing my DPhil at Oxford I applied to join the Colonial Geological Survey, hoping for a post in Fiji. None being available there, I accepted the offer of one in the Solomons. After all, they were in the Pacific too, if 2000km distant. My outward journey was one in which - as the size of the aircraft became smaller (Bristol Britannia to Sydney, Lockheed Constellation to Port Moresby, Douglas DC4 to Rabaul, DC3 to Honiara) the humidity grew greater. On landing at Henderson Field on Guadalcanal, accustomed as I was to the bleak mountains of Skye, I wondered how anyone could survive in this place.

Volcanoes, Earthquakes and Crocodiles
Brigadier Bomford
The Chief Geologist, on leave in Australia getting married, had left as my first job the making of a theodolite survey of the upraised coral terraces around Honiara in preparation for future housing developments. I had fortunately learned this skill from the legendary Brigadier Bomford, Reader in Geodesy at Oxford, by carrying out a survey of the University Parks. My next assignment was real geology: exploratory survey and mapping of the Betilonga district high in the mountains of Guadalcanal where there was the possibility of copper mineralisation. We had only the simplest of maps, drawn by the Survey draughtsman from American air photographs taken during the War. A complete cover of dense tropical rainforest leaves only the vaguest outlines of ridges and valleys and nothing of the complexity of the ground itself. The way of working in such country was by pace and compass traverse along the rivers and streams as far as their source, sampling where outcrops - if any - occur and subsequent extrapolation of geological boundaries between traverses. It takes a lot of time. I learned the survey methods from John Hill, the Rhodesian geologist who was nearing the end of his last tour, and the rules of survival in the jungle from the others in the team, the Solomon Islanders: teenage boys from the mountains who carried the loads, built the camps and cooked the food, all for £6 and a pound of plug tobacco per month, and the excellent Geological Assistants who had received a grammar school level education.

Volcanoes, Earthquakes and Crocodiles
John Grover's Survey Team
The basic work for any national Geological Survey is to produce geological maps of its entire territory while concurrently searching for economically significant mineral resources. The Chief Geologist, John Grover, now wished to extend this programme to the Western Solomons where no systematic geological survey had ever been attempted and Dick Stanton of New England University in Armidale, Australia and I were given the task. I sailed from Honiara in early August 1959 on the Survey's vessel Noula to set up a base camp on Oropie Island in the Wana Wana Lagoon (where John F Kennedy's patrol torpedo boat was rammed by a Japanese destroyer in August 1943). The Noula was a thirty-foot launch designed for ferry work in Sydney harbour but in the Solomons it regularly went on ocean-going journeys, like this one of 200 nautical miles, about 30 hours at cruising speed. On board we had two dug-out canoes strapped alongside, a 500 gallon water tank roped on the cabin roof, stores for two months, and 30 people: crew. Survey personnel and many family members including women and small children. Mercifully, the weather was benign. The Government's largest and newest vessel, the MV Melanesian, had disappeared on 10 July 1958 with 64 people on board. Its loss was never explained but a massive freak wave was one of the postulated reasons.

Volcanoes, Earthquakes and Crocodiles
MV Noula
By 18 August with the Oropie camp established I was sitting on the stern of the Noula, anchored offshore having breakfast when I heard shouting coming from the island. When I asked one of the crew what was going on he told me they were saying there was an earthquake happening. I had already felt several tremors in Honiara but this time, nothing. On a ship you don't because the sea damps out the motion. Then the ship's radio came on with the Chief Geologist telling me there had been a major earthquake with early indications of epicentre near where I was and several reports of heavy damage. I was to sail immediately for Gizo, the administrative centre for the Western Solomons, about four hours sail, and report back.

The earthquake measured 7.4 on the Richter scale then in use and caused widespread structural damage but no loss of life. Ground fissures opened, shorelines subsided and a seismic sea-wave swept away leaf houses in some coastal villages. Stanton and I saw the most spectacular effects when we traversed the island of Vella Lavella some time later. Large faults had been activated, causing landslides that destroyed swathes of jungle, clogging rivers and causing flooding. Hot springs appeared in some places and a thermal area of sulphur vents and mud pools increased significantly in size.

Volcanoes, Earthquakes and Crocodiles
Seismic Activity, 1958
The Solomon Islands form one segment of a tectonically extremely complex region of the Pacific involving interactions between the Indo-Australian plate and the Western Pacific plate. Earthquakes (now monitored by the Survey's seismic station) are common and volcanoes, dormant and active, characterize the area. Savo Island volcano, 14km north of Guadalcanal, is potentially the most dangerous. Its last eruption, probably in about 1850, wiped out the entire population in pyroclastic flows of the kind that Vesuvius produced in AD 79, engulfing Pompeii. I made one visit to Savo to check gas compositions and temperatures of the array localities that the Survey established for monitoring the volcano. I visited two other Solomons volcanoes, one, Simbo in the West, by design and the other, also in the West, by accident. Activity on Simbo consists of hot springs and fumaroles (gas vents). Past activity has been explosive causing evacuation of the population at times. The other volcano was Kavachi, a submarine vent south of Vanguno Island at the eastern end of the New Georgia group. From time to time (most recently in 2014) it erupts and forms temporary Islands that are quickly washed away. One day in 1961 I was on board the Government ship Veronica en route to Munda when we must have sailed right over the Kavachi vent that exploded when the ship was about 500m away, sending up a massive fountain of boiling seawater filled with glowing pieces of lava. The skipper ordered full speed and we watched Kavachi repeat the performance several times before dusk fell. One day Kavachi may become one of the new permanent Solomon Islands.

Volcanoes, Earthquakes and Crocodiles
Abandoned Japanese Transports
Two non-geological experiences In the Solomons remain vivid in my memory. One relates to the War of which there were many signs remaining in 1959-61: beached Japanese transports, wrecked aircraft In the jungle, abandoned shattered barges half-sunk in estuaries. Just before leaving for the West, I was called on by the Police Chief. He told me that some Japanese soldiers had been seen foraging in a village garden on New Georgia. "You take a rifle with you," he said. I assented—It was a Lee Enfield .303 for protection against crocodiles. "Well, if you find them, bring them in, will you?" "What if I can't persuade them?" "Shoot the buggers." Fortunately we never saw them.

My other memory was of going with a crocodile shooter on one of his hunts, again in the Western Solomons where the salt-water crocodile Is common. Hunting was done after nightfall. A heavy dugout canoe carried three men, the hunter up front, the paddler at the stern and. In this case me, in the middle with a powerful lamp running off a car battery. The canoe went slowly along the riverbank with the lamp light sweeping the sides. A crocodile's eyes glow red in the light. The shooter stands up and aims between the eyes. The crocodile must then be secured alongside or In the canoe in case it sinks and is lost. That Is the really exciting part, or so I was told. We saw several sets of red eyes like car rear lights but the shooter judged all of the targets unsuitable: they were all too large to take on.

British Colony Map
Solomon Islands Geological Survey Activity
Colony Profile
Solomon Islands
Originally Published
OSPA Journal 114: October 2017
Further Reading
British Solomon Islands Geological Record 1957 - 1958