Exploring off Fiji Islands

Story and Photos by K. L. Small, Western Geophysical, originally published in the 1974 Spring Western Profile

Recounted by Scott Singleton

The Doodlebugger Diary recounts the experiences of geophysicists during their working lives. I’ve published extensively on my own experiences and encourage those of you with experiences of your own to also contribute. Your fellow industry professionals would love to hear your stories.

I’ve been occasionally reprinting a series of early 1980’s articles from the GSI Shotpoints and GSI Grapevine that can be found at http://gsinet.us/. I also have reprinted various Western Geophysical Profile articles. These can be found at https://library.seg.org/page/western-profile. This month I bring you a story that shows that sometimes even doodlebuggers get to go to wonderful resort localities, as they make a point of bragging about in their very first sentence.

Figure 1: This is a typical small coral island in the Fijian group in the area where Party 73 worked.

Prologue by Scott Singleton

There are a large multitude of islands in the South Pacific that collectively elicit visions of palm tree lined beaches with clear blue water (Figure 1). Fiji is one of those island groups. It is a country with more than 300 islands located due north of New Zealand and east of northern Australia. It is a diver’s haven, and being an avid diver myself I have the good fortune of being able to spend 2 weeks there this October since it, as well as everywhere else in the South Pacific, started opening up this spring and is being mobbed by Westerners wanting to go on vacation.

However, it is not a place that inspires visions of oil derricks and hydrocarbon production. There is good reason for this – it forms a complicated wrinkle in the tectonics of the South Pacific. It is a double-ended back-arc basin with trenches on both the east (the Tonga Trench) and west (New Hebrides Trench) (Figure 2).

Figure 2a: The North Fiji Basin in its regional setting in the southwest Pacific Ocean (after Hall and Spakman, 2002; Mann and Taira, 2004; Schellart et al., 2006; Whattam et al., 2008). Light grey=¼ oceanic crust. Dark grey = oceanic plateaus or island-arc crust. NZ = New Zealand; PNG = Papua New Guinea. CR = Colville Ridge; FP = Fiji Platform; KR = Kermadec Ridge; LHR = Lord Howe Rise; LR = Lau Ridge; MBP = Melanesian Border Plateau; NFB = North Fiji Basin; NC = New Caledonia; NR = Norfolk Ridge; OJP = Ontong Java Plateau; S = Samoa; SCT = San Cristobal Trench; SI = Solomon Islands; TR = Tonga Ridge; VA = Vanuatu Arc; VT = Vitiaz Trench. Black arrows show direction and rate in cm/yr of motion of the Pacific Plate relative to the Australian Plate (DeMets et al., 1994; Mann and Taira, 2004). Figure 2b: Main tectonic elements of the North Fiji Basin (NFB) (after Auzende et al., 1995a; Lagabrielle et al., 1996; Pelletier et al., 2001; Ruellan and Lagabrielle, 2005). White areas outlined in black = island arc crust. Black = Islands: A = Aneityum; Ef = Efate; Es = Espirito Santo; M = Malekula; Ta = Tanna. Ridges: Ba, Bl and Br¼Balmoral, Bligh and Braemar (after Jarvis et al., 1994); D = D’Entrecasteaux; WT = West Torres Platform. Spreading Ridges: CSR = Central; FSR = Futuna; HH = Hazel Holmes; SP = South Pandora; Tr = Tripartite; WFR = West Fiji; Fracture Zones: EFZ = Epi (after Greene and Collot, 1994; Raos and Crawford, 2004); HFZ = Hunter; NFFZ = North Fiji. Thin arrows show representative GPS convergence rates between the Vanuatu Arc and the Australian Plate (Calmant et al., 1995, 2003; Taylor et al., 1995; Wallace et al., 2005, 2009). In the Aneityum Tanna area rates are 116–124 mm/yr, in Efate 86–94 mm/yr, while in Espirito Santo and Malekula they are 17–43 mm/yr. Images in (a) and (b) from Earthquake Report, North Fiji Basin; Jay Patton Online, http://earthjay.com/?p=4761.

It had an unusual genesis whereby the existing subduction zone split, forming a back-arc basin that then became double-ended (Figure 3).

Figure 3: Tectonic reconstruction of the New Hebrides – Tonga region (modified and interpreted from Auzende et al. [1988], Pelletier et al. [1993], Hathway [1993] and Schellart et al.(2002a)) at (a) ~ 13 Ma, (b) ~ 9 Ma, (c) 5 Ma and (d) Present. The Indo-Australian plate is fixed. DER = d’Entrcasteaux Ridge, HFZ = Hunter Fracture Zone, NHT = New Hebrides Trench, TT = Tonga Trench, WTP = West Torres Plateau. Arrows indicate direction of arc migration. During opening of the North Fiji Basin, the New Hebrides block has rotated some 40-50° clockwise [Musgrave and Firth 1999], while the Fiji Plateau has rotated some 70-115° anticlockwise [Malahoff et al. 1982]. During opening of the Lau Basin, the Tonga Ridge has rotated ~ 20° clockwise [Sager et al. 1994]. Image from Earthquake Report, North Fiji Basin; Jay Patton Online, http://earthjay.com/?p=4761.

As one might assume, this young and continually evolving region is very seismically active with volcanoes, spreading centers, and subduction zones (Figure 4).

Figure 4: Earthquake hypocenters from the USGS catalogue (earthquakes from 0 to 70 km depth excluded for clarity), overlain on shaded relief bathymetry showing tectonic elements of the Vanuatu/Tonga area. FP= Fiji Platform. HFZ= Hunter Fracture Zone. NC = New Caledonia. S = Samoa. From Martin (2014), extracted from Earthquake Report, North Fiji Basin; Jay Patton Online, http://earthjay.com/?p=4761.

So the question becomes – why would anyone want to shoot seismic here? Unfortunately, folks, I don’t have the historical records for this survey (i.e. who was the client and what was their exploration objective) and am as mystified as I’m sure you are. Nonetheless, someone wanted to acquire the data and put up the money to do it, which then resulted in some lucky doodlebuggers getting a trip to a South Pacific island.

Fiji Islands, South Pacific

IT IS NOT EVERY DAY that a person has the chance to go on an all-expense-paid cruise of the South Pacific aboard a modem, air-conditioned yacht equipped with all of the latest modern conveniences and get paid to boot! Had you been aboard the Bayou Chico or the Wayne Walker with Party 73 during the months between last June and September however, you would have had such an experience. Not too many South Seas yachts tow a streamer cable, and most have better sense and stay away from coral reefs. On the other hand, if you are a bunch of Western "doodlebuggers" who specialize in working in and around coral reefs, you will probably end up in the Fiji Islands as we of Party 73 did; because if it is coral reefs that you arc after, Fiji has some beauties.

Figure 5: The Wayne Walker returns from setting up base stations for Party 73's operations.

The Wayne Walker (Figure 5) was the first to arrive in Fiji, and it began setting base stations in places where no one had put them before. This kept the boat crew occupied most of the time. In their "spare time" they set calibration buoys, pre­ran the programmed lines with a fathometer, scouted reef passages, reset the calibration buoys (the natives really liked our buoys), and then re-ran the lines.

Using a technique that was perfected in the Trobriand Islands of New Guinea, the survey crew aboard the Wayne Walker scouted all programmed lines with the aid of aerial photographs of the prospect area. Consulting with the on­board client representative, they were able to alter program as scouting progressed. "Safe" lines were marked on the trackplots along with the water depths. These trackplots were given to the recording vessel each night when the two ships anchored. It was not uncommon, however, for the Wayne Walker to run lines four and five times in order to find the right combination of water depths, reef passages, and room to maneuver that would allow the Bayou Chico to pull the streamer cable safely through the reefs.

As the entire program lay within a gigantic coral reef complex that was completely unchartered and bristling with thousands of coral heads and pinnacles, both ships on a few occasions did, unwillingly, employ the “contact” method of reef location. Though damage was minimal, this method cannot be recommended. Even the South Seas veterans aboard Party 73 had to admit that Fijian coral was different from anything that they had ever run into before (figuratively speaking, of course). But our intrepid survey crew never missed a pop as the AQUAPULSE® guns continued to bang away and the satellite navigation crew kept us on track (except for occasional brushes with the mysterious “transducer grabber,” likely rogue coral heads).

The crew initially called Lautoka, on the northwest coast of the main island of Viti Levu, home port. Later as program progressed operations moved to Suva, the capital of Fiji, on the other side of the same island. After such exciting and fascinating ports as Daru, New Guinea; Merauke and Sorong, West Irian; and Makasar, Indonesia, which Party 73 has had the opportunity to visit many times in the past few years, Fijian ports seemed to be somewhat sedate.

The infamous Golden Dragon in Suva, however, was known to possess a magnetic force of sufficient strength to attract unwary crewmen.

Figure 6: This Indian temple reflects the multiracial society of the Fiji islands.

Ports are ports, but Party 73'ers would agree that Fiji is outstanding because of its people. A most unique, multiracial society comprised of approximately 230,000 descendants of the native Fijians; 250,000 Indians (Figure 6); 5,000 Chinese; and 3,000 Europeans, Fijians possess a genuinely warm and outgoing personality that is rare in the world today (Figure 7). The Fijians have not always been the friendly people who greet today's arriving visitor, however. As late as the 1800's cannibalism was widely practiced here, the last recorded feast being in 1852. More startling is the fact that cannibalism in Fiji was based not on any religious sacrifice or significance or on hunger or famine but on the gruesomely simple fact that the people liked the taste of human flesh.

Figure 7: Indian women shop in native dress. Most of Fiji’s Indian population is descended from contract laborers brought from India in the late 1800's.

Today most Fijians take tourists' queries concerning cannibalism in good humor and with no feelings of shame. The best example of this attitude was expressed by the late Ratu Sir Edward Cakobau, 0BE, Oxford-educated former prime minister of Fiji, who was asked at a formal state banquet in England by a tipsy matron if cannibalism were still practiced in his country. At that moment he was being presented the wine list by the waiter. In a booming voice, which was picked up in a nearby microphone, he loudly told the waiter, "I'll select the wine after I examine the guest list!''

Figure 8: Party 73 crew members saw the sights of Fiji when they got a break and found sugar cane to be on important crop. In this picture farmers pull cut sugar cane through a field with a team of oxen.

Fijians are proud of their past and their culture (Figure 8, 9); and a large number of islanders still live in grass huts, or bures, at their own choosing.

Figure 9: Against a beautiful background of mountains and clouds a farmer plows with oxen in a sugar cane field.

Each year the government awards a most sought-after prize for the cleanest, neatest, and most authentically Fijian village. Unlike many Pacific Island villages that are strewn with cans and coconut husks and swarming with flies and mangy dogs, Fijian villages are a visitor's delight with green lawns and beautiful tropical flowers neatly planted and carefully maintained around each bure (Figure 10). The warm Fijian greeting, hula, is extended any and all who enter.

Figure 10: Fijian villages, set in beautiful surroundings and typically clean and neat, are a visitor's delight. The grass huts are called bures, and many Fijians are still living in them.

Unfortunately, all things must come to an end sometime--even seismic jobs. At the completion of the job the seismic crew was flown to Singapore while the Bayou Chico (Figure 11) made a momentous journey across the Pacific arriving home to the United States after 10 years of working foreign waters. Leaving shortly after for Singapore was the Wayne Walker, which made a brief stop in beautiful Port Moresby, New Guinea, everybody's favorite port.

Figure 11: The Bayou Chico heads for port in Loutoka, Fiji, after a long trip.

The South Pacific is a vast, unexplored area teeming with razor sharp coral, typhoons, hungry sharks, and other hazards; but in spite of these dangers, it would not be too difficult to persuade a certain group of doodlebuggers, now widely dispersed, to return (Figure 12).

Figure 12: Party 73 crew members managed to take some time off from their duties to enjoy the beautiful beaches of Fiji such as this one.

Epilogue

Have you ever wondered what happens to old seismic boats? In today's throw-away, nonreturnable society, it is interesting to note that old seismic boats seem to be “recycled” for other purposes.

A Western visitor to Singapore or Bahrain might be amazed to see a profile that looks strangely familiar under another name and flag still working away as a crew boat, tug boat, or work boat. One such veteran of many miles and many places is the former F. B. Walker. Sold in Singapore, her whole superstructure from the wheel house back was completely cut away. In its place was reconstructed an air-conditioned bar adorned with brass fillings and a dance floor of teak planking. At present she is operating in the Fiji Islands registered as the South Seas Mana and flying the Fijian flag (Figure 13). Daily she hauls tourists from Lautoka, Fiji, to an offshore island some three hours away, on which is constructed a posh resort-type native village. As there is no fresh water on the island, the boat's other duties include hauling all of the water and also the diesel fuel for the island's generators.

Figure 13: The South Seas Mana, formerly the Western seismic vessel F. B. Walker, awaits passengers in her new role as a tourist boat taking vacationers from Loutoka, Fiji, to on offshore resort island.

A trip aboard the old F. B. is a heartwarming experience for a Westerner. One only wonders if the voices of the hundreds of Westerners who ever sailed her could be heard again what tales of adventure they could tell. Since censorship does exist in Fiji, however, it is probably better that these old voices remain silent. Today even above the scream of the engines and babble of the tourists, one strangely seems to hear a long-forgotten voice occasionally yell, “Back 'er down.”

They say that old soldiers never die, they just fade away. Probably with the F. B. it was just a case of giving the old girl a rest. In any event, a boatload of bikini-clad tourists is not a bad way to go!

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