Volcanos of Vanuatu

 'Rim of Fire'

The landform of Vanuatu broke the surface of the ocean 22 million years ago in a writhing mass of molten lava spewing from the bowels of the Earth. Massive movements in the ocean's crust formed a rift stretching along the Western edge of the Pacific Ocean, named the Pacific Rim of Fire. Along this rift, chains of submarine volcanos percolated through at intervals, compiling land masses upon themselves until they reached the surface thousands of feet above. The result in Vanuatu is the island chain we see today. Vanuatu has several active volcanos along with inactive and extinct ones. The most active and interesting are those on Ambrym, Tanna, Lopevi and Gaua Islands and are given a closer look below.

Yasur

On the island of Tanna in the Southern most group of Vanuatu, lies Yasur volcano. Yasur is a small pyroclastic cone situated within the relatively small Yendahe caldera, formed tens of thousands of years ago. It has been described by many as one of the most accessible volcanos in the world. As a result, thousands of tourists have visited its rim to view the wonders of its active crater. The steam and gas cloud eruptions mixed with ash, travel high in the atmosphere signaling its daytime presence. And the glow and fireworks from it's cone at night have guided sailors from the time of Captain Cook's first glimpse in 1774 to the present day yachters voyaging from the Fiji island to the East.

Located on the Southern end of Tanna, it is easily accessed via a dirt road that traverses the island from Lenakel to Port Resolution. The trek to the volcano rim begins at the parking area, a designated patch of the vast desolate ash plain. The hike up the ridgeline to the 1000 ft rim takes only 15-30 minutes. The views however are impressive. Most visitors time their hike during the afternoon-evening hours to take advantage of the incredible views and the the spectacular nighttime lava displays.

Yasur is monitored, as with all the active Vanuatu volcanos, by the French scientific organization ORSTOM via remote sensing equipment, to provide up-to-date information on the volcano's activity levels. When specified levels of activity are registered, increased restriction perimeters are established to provide safety to visitors.

In Yasur's case a danger level scale of I-III is used to guage the access danger level. There are viewing safety perimeters set based on the scale. As any active volcano is very unpredictable, caution should always foremost in any visitor's mind. In fact in the past years there have been 3 deaths attributed to failure to observe proper safety precautions and venturing too close to the active crater or into the lava bomb field during posted dangerous timeframes.

For the most part though, Yasur puts on an incredible display with steam and gas clouds and lava sprays that can be viewed from a safe distance. During the rainy season when more ground water interacts with the thermal forces of the volcano, more explosive eruptions can be expected, sometimes ejecting huge lava boulders. 

At the base of Yasur there was, until the year 2000, a small body of water named Lake Siwi which drained rapidly when the eroded banks gave way. The ensuing flood wrecked havoc upon several villages downstream of the lake.  A more common hazard from the ash plain involves the erosive forces of heavy rainfall that dissolves the hardened ash into fluid mud, with flows sometimes destroying downhill villages in this manner.

With Yasur's ease of access, it seems the more likely of any of Vanuatu's volcanos that the cast members might have occasion to visit. Perhaps the Final 3 will make a journey to pay tribute to their Fallen Comrades. Or Yasur could be included in one of the several Reward getaways that are included in the program each series. In any event, Yasur's wonders are too spectacular and too convenient to be missed by any visitor to Tanna, and will surely put you in touch with the forces of nature on this Earth.

Lopevi

Lopevi volcano is a classic cone shaped strato-volcano occupying almost the entire land mass of Lopevi Island in the Malampa Province of the central island group of Vanuatu. It has an elliptical footprint of 33 by 45 miles across at the base, and rises to 4636 ft at its summit. Lopevi has been almost constantly active over the years with frequent ash eruptions and periodic pyroclastic and lava flows. The last powerful eruption occurred in 1970 when a fracture on the Northwest flank released steam and lava flows threatening the nearby small population. The few villages were promptly evacuated and resettled onto nearby Epi Island. Lopevi remains uninhabited due to it's unreliable safety conditions.

Pyroclastic flows and landslides have caused impressive damage to the flanks at various locations on the volcano flanks, taking out vast forested jungle areas in their rush to satisfy gravity and meet the sea. The ash flow deposits remain superheated and are hazardous to venture onto. And the lava bomb fields near Lopevi's summit are also a constant hazard requiring excellent timing and good luck to avoid an active encounter. With virtually all sides of the volcano at risk, visitors have no reasonably safe approach. Thus few if any tourists visit Lopevi volcano and only dedicated vulcanologists venture close enough to experience the specific features of Lopevi on land, and then only with professional caution.

With its distinct cone profile, Lopevi nicely fulfills the role of the classic tropical volcanic island isolated in the vast South Pacific. It is unlikely however that the Survivor production team will visit Lopevi due to the frequent danger, but it might appear in scenic fly-bys allowing an instilling of a 'Bali Hai' feeling for the Vanuatu Survivor production.

Ambrym

The island of Ambrym in the Malampa province of the central grouping of the Vanuatu island chain, contains a large pyroclastic basaltic shield volcano about 21 by 30 miles wide and 5900 ft tall. The main cone is a massive caldera, atypical of volcanos in the area. The caldera is 7 miles in diameter and contains two active individual intra-caldera cones, Benbow and Marum and a third newly active cone Niri Taten, rising from within the cauldera. 

Ambrym is the most active in the Vanuatu chain in terms of volume, and is most famous for its almost ever-present lava lakes within the active cones. Most of the semi-continuous eruptions of Ambrym are paralleled by earth tremors that keep any inhabitant of Ambrym aware of the presence of a volcano in their backyard. The eruptions primarily involve gaseous steam and ash distribution into the atmosphere with the occasional downpour of acid-rain. The latter is of concern and has affected the Ambrym villages water supplies from time to time and destroyed crops as well.

But in general Ambrym is a  sleeping giant and relatively safe to be around if your nerves allow it. And because of its massive size, safe distances are easy to maintain, and any visitor's journey to overlook the volcano involves long hours of arduous travel through alien landscapes. But peering into the very throat of a volcano can be an amazing and humbling experience, but is one that vulcanologists and many visitors regard as a lifetime experience.

The Ambrym volcano has had massive eruptions over its existence, and has shared the long developmental history associated with shield volcanos. The caldera itself was created in about 50AD as the volcano exploded and collapsed upon itself and grew slowly over a very long time, building upon itself through successive lava flows into the flattened dome shape of today. As lava vented thru faults, the active intra-cones of Benbow and Marum emerged over time. And their active lava lakes provide evidence of the magma pool breaching the crust of the Earth here throught these faults.

The interior of the huge caldera is marked by a distinctive black ash plain that provides a unique experience to any visitor. The ash plain itself is a study in volcanic activity. It is the result of Plinian eruptions; massive gaseous eruptions floating tiny magma fragments (ash) as high as 20 miles. The resulting ash-fall spreads over a large area and accumulates into deep blankets of ash. Ambrym's ash plain is the result of many of these Plinian eruptions. Within the caldera, the ash accumulates into flat surfaces swept by the elements into rippled surfaces similar to an ocean floor.

Outside the caldera, on the sides of the volcano, rain and wind have eroded huge intrusions in the form of mazes of linear canyons. Some of these ash floods have created riverbeds flowing to the sea. A journey through this area is unlike any place on Earth, and surrealistic in the most descriptive sense of the word. Thus any journey to visit Ambrym requires a day to fully appreciate the ash plains by themselves as well as time to explore the caldera and cones above. Unlike Yasur volcano of Tanna, Ambrym is a full-on expedition for a visitor, requiring physical commitment and endurance. But the rewards are sights beyond your imagination and your senses. And it is definitely the road less traveled.

Because of its remoteness and unpredictable level of danger, it seems unlikely that any Survivor cast will have the time or the stamina to travel up the ash plain corridors to the caldera of Ambrym. In fact one recent photographic expedition had its camera lenses melted when unexpected gaseous eruptions swept over them for extended periods. It could however, easily be included in scenic footage because of its incredible landscapes never previously seen in any Survivor production. Additionally the villages of the island of Ambrym itself could be the subject of a production visit for challenge purposes, as the people of Ambrym are unique in their kastoms and beliefs, one of which delves into the realm of Black Magic.

Gaua

Gaua volcano emerges from Gaua Island lying in the Banks and Torres Islands, of Torba province in the Northern island group of the Vanuatu archipelago. Gaua is a strato-volcano, with a large caldera rising 2614 ft. and summited by the active cone of Mt Garet. A strato-volcano is one that emits both lava flows and ejected material. On the South slope of the volcano are solfataras fumeroles which emit strong sulphurous gases through vents, while on the North side are Sladen Boiling Springs and a massive waterfall pours down the slopes on yet another side. Because of the sulphurous gas emissions from the solfataras fumeroles and the periodic eruptions from the Garet cone, the cinders covering Mt Garet are extremely colorful and give this volcano a unique look among the volcanos of Vanuatu.

Surrounding MT Garet's base, within the Gaua caldera, lies a crecent shaped crater lake named Lake Letas/Steaming Hill Lake. The water of Lake Letas is very warm and only eels and shrimp are able to survive the 32 degree celcius temperatures. Another anomaly is that this freshwater lake, which lies at 1500 ft elevation, rises and falls with the ocean tides. Due to the extremely close location of the caldera lake to the active cone of MT Garet, the possibility of subsurface water-magma interaction is high. Such a meeting could result in explosive eruptions and warrants great caution in approaching the MT Garet active cone.

Prior to 1962, eruptions consisted mostly of sulphuric gases. From this period on, the eruptions have progressed to crater explosions and frequent ash column emissions, indicating an increased level of volcanic activity. The remoteness of even getting to the caldera crater lake might be overcome via helicopter, but the unstable nature of MT Garet and its progressive recent history probably preclude any visit by the Survivor cast. Most of the visitors to Mt Garet on Gaus Island are professional vulcanologists monitoring the volcano's activity. Thus while Gaua volcano with its Mt Garet active cone and crater lake is extremely interesting and colorful, its  danger and remoteness will probably be the reasons it's not seen or used as a Survivor backdrop.