Page 77 - Volcano and Geothermal Tourism

Case Study 1

Reunion Island, France

Piton de la Fournaise Volcano

Henry Gaudru within the youngest caldera, which is 8km wide
and breached to below sea level on the eastern
Introduction side (Smithsonian Institution, 2009). The eruptions

Reunion Island owes its impressive relief and of Piton de la Fournaise are generally of the
Hawaiian style: fluid basaltic lava flowing out with
landscapes to an active volcano (Piton de la fire fountaining at the vent. Occasionally, phreatic
Fournaise) and to three ancient cirques resulting eruptions (groundwater steam-generated
from very large collapses (Salazie, Mafate, Cilaos). eruptions) occur. Lava flows crossing the Grand
These two impressive mountain ranges are Brûlé can occasionally reach the sea, with
separated by two high plains (Plaine des Cafres spectacular results.
and Plaine des Palmistes). The island, located in More than 170 eruptions, most of which have
the western Indian Ocean is a favourite destination produced fluid basaltic lava flows, have occurred
for hikers, mountain bikers and horse riders. since the 17th century. Some eruptions, in 1708,
Reunion Island provides many itineraries with the 1774, 1776, 1800, 1977 and 1986, have originated
option of a night stay in a mountain lodge for the from fissures on the outer flanks of the caldera.
longer ones. Well-kept marked trails (including The most recent large-type eruption began on 2
two for long treks) enable visitors to discover this April 2007 with rare intensity. Cracks opened at
beautiful volcanic landscape.
low altitude and emitted fountains of lava which
Piton de la Fournaise volcano poured into the ocean – several million cubic
(Furnace Peak) metres of incandescent rocks. The inhabitants of
the village of Tremblet located in the vicinity,
The massive Piton de la Fournaise basaltic shield worried about lava flows in the Enclosure, which
volcano (2631m) is one of the world’s most active fortunately did not occur, nevertheless underwent
volcanoes. Much of its >530,000 year history bombardment from ash and lapilli, sulphur gas and
overlapped with eruptions of the deeply dissected acid diffusion, and forest fires. In addition, the
Piton des Neiges shield volcano to the north-west. withdrawal of the lava contained in the magmatic
Three calderas formed at about 250,000, 65,000 chamber present beneath the volcano caused a
and less than 5000 years ago by progressive colossal collapse of the Dolomieu crater.
eastward slumping of the volcano. Numerous Volcanic activity of the Piton de la Fournaise is
pyroclastic cones dot the floor of the calderas and constantly monitored by geophysical sensors
their outer flanks. Most historical eruptions have (tiltmeters, extensometers, differential GPS receivers,
originated from the summit and flanks of etc.). The data from those various sensors are sent
Dolomieu, a 400m high lava shield that has grown to the volcanological observatory located in

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