Terres Australes Research Articles

Ailleurs imaginés, Littérature, Histoire, Civilisations ed. by Jean-Michel Racault

Book Reviews Jean-Michel Racault, ed . A i l l e u r s I m a g i n é s . L i t t é r a t u r e , H i s t o i r e , C i v i l i s a t i o n s . Paris: Diffusion Didier-Erudition, 1990. Pp. 256. The sixteen essays in this collection—organized by the Centre de Recherches Littéraires et Historiques and the Centre Inter-Disciplinaire de Recherches Afro-Indien-Océaniques, both located at the Université de la Réunion—afford perspectives on a wide range of topics from the ancient world to the modern era: imaginary languages and imaginary voyages, the linguistic and ideological quandaries o f native writers reared in colonial territories (such as the Antilles), papers on Cyrano de Bergerac’s works, Gérard de Nerval’s Voyage en Orient, Patrick W hite’s Voss, and Salman Rushdie’s M idnight’s Children, to mention a few examples. In a well-organized and informative essay, Gérard Blanc treats the reciprocal relation­ ship between the contents of the Voyages imaginaires..., the 36-volume collection edited by Charles Garnier and published from 1787-1789, and the set o f three ensuing volumes deal­ ing with accounts of authentic shipwrecks. Another absorbing article is Jean Garagnon’s “ Rousseau et la pensée utopique: le Contrat social et le Voyage de Robertson aux Terres Australes.” The Voyage de Robertson, published anonymously in 1766, concerns a pur­ ported voyage in 1585 but includes extended references to the Contrat social of 1762. Garagnon emphasizes the degree to which Rousseau’s work was used to defend the caste interests of the French nobility. The essay is enhanced by a good set of notes and is a pleasure to read. Since this project was organized in La Réunion, it is appropriate that some of the finest papers concern that very region, including Sophy-Jenny Linon’s “ Contraintes et enjeux idéologiques d ’une topographie imaginaire: les Terres Australes inconnues d’Etienne de Flacourt (1661) et de l’Abbé Jean Paulmier (1663),” which deals with Madagascar. Jean-Claude Carpanin M arimoutou’s “ La Lémurie: un rêve, une langue” covers an arresting, indeed unforgettable, subject: the mind-blasting work of Jules Hermann, Les Révélations du Grand Océan, published posthumously at the end of the 19th century. Her­ mann, the mayor of a town in La Réunion, imagined a fabulous continent in the South Seas in a distant prehistoric era—Lemuria, inhabited by a race of white-skinned giants who exerted a formative influence on the cultures and languages of virtually the entire globe. A cosmic catastrophe caused Lemurian civilization to sink beneath “ le Grand Océan,” i.e., the Indian and Pacific Oceans combined. Traces of the submerged continent found on islands such as La Réunion and Maurice offer signs or clues to be deciphered and inter­ preted. The way was open for a binge of extrapolation in which everything is inverted. Madagascar and its neighboring islands are the center of the world; the language spoken there, le malgache, is the least debased form of the original Lemurian tongue. Europe, to be sure, is Elsewhere, on the fringe. Most languages, including French, have their source in Lemuria. (Hermann excluded the Chinese language, which he believed “ inhuman, extra­ terrestrial” ; indeed, the Chinese were a prime target for his marked racism.) So visionary a scheme entailed nimble etymological gymnastics in the service of a world turned inside out. With a touch of dry humor, Professor Marimoutou cites a passage in an article on “ Creole Mythologies” by Jean-Louis Joubert who informs us that when portions of Hermann’s work were published during his lifetime, “ this Lemurian mythology was received with reti­ cence by the general public on the islands” (123). Overall, the quality of these essays is of a very high caliber; the volume deserves to be on the shelves of research libraries. J o h n T . O ’C o n n o r University o f New Orleans 130 W i n t e r 1994 ...

Previously undetected earthquakes in the southern hemisphere located using long-period Geoscope data

At the high latitudes of the southern hemisphere, the seismicity maps are strongly biased as a consequence of the low density of seismic stations and the high permanent microseismic noise. In the frame of the Geoscope project, a network of four long-period and broadband stations has been set up in Antarctica, Crozet and Kerguelen Islands, and New Caledonia by the Institut de Physique du Globe de Strasbourg, the Terres Australes et Antarctiques Francaises, and the Office de la Recherche Scientifique et Technique d'Outre Mer. This network has revealed that about 200 earthquakes of magnitude 4.3 to 5.5 were ignored each year in the global seismicity for that part of the Earth. Using the propagation of Rayleigh waves and a simple velocity model, about 20 earthquakes have been located for 1986 in South Pacific Ocean, South Indian Ocean, and Antarctica, with an accuracy on the order of 100 km. These new events provide a refined image of the seismicity at the high southern latitudes. Most of them are located along the plate boundaries between the Antarctic, Australo-Indian, and Pacific plates. A few events located in Pacific Ocean east of Australia and on the Antarctic plate could possibly correspond to a small intraplate activity. These preliminary results show the potentiality of significantly improving the seismicity maps at the southernmost latitudes from Rayleigh-wave analysis if a greater number of broadband stations and regional velocity models are used.

The function of the pacific in the french fifth republic's ‘grand design’:Theory and practice of the ‘puissance mondiale moyenne

ments of the 19th, French presence in the Pacific towards the end of the 20th century is usually associated with the Gaullian decision to use Polynesia as a testing ground for the French independent nuclear deterrent, cardinal principle of French international policies since the 1960s. The present French involvement in the Pacific should also be related to a second and more general cardinal principle, the determination to preserve and strengthen France's status as a puissance mondiale moyenne, a middle-sized world power ? the only one in this unusual category, and reflecting the extroverted character of the French State as a territorial entity. In the Constitution of the Fifth Republic (1958) as well as in administrative practice, media coverage, and the average Frenchman's mental image, the French State as a territorial entity extends around the world through the network of the DOMs ('D?partements d'Outre-Mer': Martinique, Guadeloupe, Guyana, Reunion), the TOMs ('Territoires d'Outre-Mer': New Caledonia, Wallis and Futuna, French Polynesia, and Terres australes et antarctiques on the southern fringe of the Indian Ocean), the Collectivit?s territoriales (St Pierre-et-Miquelon, Mayotte), and some uninhabited dependencies (?lipperton, or the 'Iles ?parses' around Madagascar). These distant lands are no longer seen as mere French possessions in the old colonial tradition but as intrinsic parts of France itself; they stand as terres de souverainet?} lands under French sovereign jurisdiction, a term dating back to the expansionist policies of Louis XIV. Geopolitical cohesion of the French State throughout the world is reflected in the administrative principle of continuit? territoriale? coined originally for the

The Kerguelen Isles (southern Indian Ocean): new results on deep structure from refraction profiles

Additional seismic refraction profiles shot across the Kerguelen archipelago (Terres Australes et Antarctiques Françaises known as TAAF) located in the southern Indian Ocean, substantiate the oceanic-type crust of the archipelago (and the Kerguelen Plateau as well). The crust-mantle boundary is better modelled by a transition than by a discrete interface. Seismic velocities of 6.60–6.80 km/s are in the range of those within oceanic layer 3. Velocities of 7.2–7.5 km/s observed at long ranges may be interpreted according to at least two distinct hypotheses: 1. (1) Notwithstanding their rather low values, they represent upper mantle material and might be assigned to peridotites serpentinised by hydrothermal circulations, as reported for various oceanic and continental features; 2. (2) these velocities are assigned to the lower crust intruded by melt produced by adiabatic decompression of upper mantle material during rifting (underplating). A small increase in mantle temperature caused by the presence of heat sources i.e. the Southeast Indian Ridge and the Kerguelen mantle plume nearby, may have produced huge quantities of melt facilited by the slow movement of the Antarctic plate, then building up the aseismic Kerguelen Plateau.

The Dumont D'Urville aerodrome, Terre Adelie, Antarctica

Under satisfactory technical and ecological conditions, a coastal airstrip with the necessary security requirements for medium carriers will be constructed in Terre Adélie by October 1992. Inspired by the “Terres Australes et Antarctiques Françaises” (TAAF), it will provide better opportunities for scientific research with air access from Dumont d'Urville to Dome “C”, the planned research base. It will enable summer campaigns to benefit fully from the season without ice restrictions and it will reduce the need for a passenger cargoboat. The only possibility for achieving this is to connect islands by means of a causeway along the same axis as the prevailing wind. The “Expeditions Polaires Françaises” have thoroughly researched the site in “Pointe Geologie Archipelago” and have carried out a complete study of the local environment by collating all the observations concerning wind, sea swell, current, pack ice and geological features. These have led to a theoretical causeway model and consequently to an “experimental model” where studies of swell-ice-structure interactions, stability in the presence of ice and measurements of swellings, tide and porosity of the embankment have been made. Revetment tests have allowed for the construction of a bi-layered roadway. To date, the causeway reaches the last island. The main island has been blasted and a zone has been prepared for the future hangar and control tower. Nearly 4% of the cost of the project will be used to protect the fauna (new nesting zones, movement to protected areas and enclosure of the airstrip). Observations made during the 1989 winter show that this causeway does not disturb the migration of Emperor penguins.

Contribution a l'etude de la structure profonde du banc de Crozet (Ocean Indien Austral)

The Crozet Bank, the eastern part of the Crozet Plateau (southern, Indian Ocean), is capped by two groups of islands that form the Crozet archipelago (Terres Australes et Antarctiques Françaises). A N S trending 1500-m deep basin, the Indivat Basin, cuts the Crozet Bank between the two island groups into two parts bearing different geological and volcanic characteristics: in the west, a 2.5-km thick basalt layer indicating well-developed volcanism, and in the east, a thin basalt layer and layer 3 just below a detrital layer. Such an arrangement may resemble that observed in oceanic structures where serpentinized peridotites have been cored just below the sediments. The interpretation of gravity anomalies on Ile aux Cochons and Ile de la Possession combined with marine geophysical data collected in the surrounding regions of the southern Indian Ocean shows that the crustal thickening observed below the Crozet Bank is caused by a > 12-km thick layer 3 which precludes local Airy-type compensation of the Crozet Bank. The isostatic compensation of the Crozet Bank is mainly achieved by lower density material within the upper mantle down to a depth of 50 km. The compensation level is 60 km deep. A long-wavelength heat flow anomaly observed over the eastern region of the Crozet Plateau indicates that the lower density of the upper mantle is of deep thermal origin within the lithosphere.

A bibliography of terrestrial ecosystems on Iles Crozet, Indian Ocean

AbstractThis research bibliography gives a brief ecological account of lies Crozet (Terres Australes et Antarctiques Francaises) and lists over 370 studies in terrestrial and freshwater ecology (including laboratory studies) under five headings — history and general aspects, earth sciences, botany, invertebrate fauna, vertebrate fauna.

Harpacticoïdes (Copépodes) Des Iles Crozet Iii - Description D'Une Espèce Nouvelle Du Genre Leptastacus T. Scott

A new species of Harpacticoid Copepod belonging to the family Cylindropsyllidae Sars and to the genus Leptastacus T. Scott, 1906, is described on the basis of specimens collected in the Crozet Islands (Terres Australes et Antarctiques Francaises). The discussion includes a key to the species of the genus Leptastacus.

First scientific expedition to Ile des Pingouins, Archipel Crozet

AbstractFrom 14 November to 12 December 1986 a five-man team surveyed Ile des Pingouins, an islandin the lies Crozet archipelago only once previously visited by scientists. Supported by Terres Australes et Antarctiques Francaises (TAAF), the team investigated the geology, climate, botany, invertebrate zoology and ornithology of the island.

Harpacticoïdes (Copépodes) Des Iles Crozet II. Description D'Une Espèce Nouvelle Du Genre Tapholaophontodes Soyer, 1974

A new species of Harpacticoid Copepod, belonging to the family Ancorabolidae Sars and to the genus Tapholaophontodes Soyer, is described on the basis of specimens collected in the Crozet Islands (Terres Australes et Antarctiques Francaises). The discussion includes a key to the Ancorabolidae.

A seismic refraction survey in the Kerguelen Isles, southern Indian Ocean

Two 65 km long on-land refraction lines, with shot detonated at sea, were implemented in the Courbet Peninsula, eastern region of the Kerguelen archipelago (Terres Australes et Antarctiques Françaises, southern Indian Ocean). The first profile P1, oriented NE—SW, runs from Cap Ratmanoff toward Mont Ross, and the second one, P2, from Pointe Suzanne, SE of the Courbet Peninsula, through the Val Studer. Data from both profiles were supplemented by using the Bouguer gravity anomaly map not previously studied. The data combined standard travel-time interpretation, wide-angle reflected wave study, synthetic seismograms and S-wave analysis. The velocity—depth behaviour shows that the mean crustal thickness ranges from 14 to 17 km only, varying with the locality. The structure of the crust beneath Kerguelen resembles those observed beneath aseismic ridges (i.e. the Crozet Rise and the Madagascar Ridge). Average velocity of 5.5 km s−1 on both lines is in the range of those determined for oceanic layer 2, which is there 8–9 km thick. Average velocity of 6.6 km s−1 is in the range of velocities within oceanic layer 3. The transition to mantle velocity, 7.95 km s−1 is best modelled by a positive velocity gradient within the crust. This feature is similar to that observed on structures generated near spreading centres. These new data combined with geological and geochemical investigations in the archipelago support an oceanic origin for the Kerguelen—Heard Ridge, and also Broken Ridge. Both structures were joined 40 Myr ago, as shown by the magnetic anomaly pattern. Refraction studies invalidate the assumption that isostatic compensation is achieved by a 23 km deep crustal root, but substantiate the contribution of a low velocity mantle. Gravity data are consistent with refraction studies. No crustal root appears to be present beneath Mont Ross. The best match between gravity and refraction data in the Val Studer is obtained by assuming the presence of a shallow intrusive body, related to the fault and dyke system, and Montagnes Vertes plutonic intrusive complex nearby.

Indian Ocean Gas Study

In July 1984, a joint French‐U.S. team of scientists embarked on the first in a series of research cruises in the southwest Indian Ocean aboard the research/supply vessel Marion Dufresne, which is operated by Terres Australes et Antarctiques Francaises (TAAF). This monthlong cruise marked the debut of a multiyear program aimed at delineating the distribution of anthropogenic CO2 in the Indian Ocean.Deep waters from the Atlantic, Pacific, and Indian oceans move to the southern ocean and mix there. The resultant relatively homogeneous water becomes the major source of the Antarctic bottom water, which spreads back out into the deep world oceans. Consequently, the chemistry of southern ocean water is a baseline for the deep world oceans. Therefore the carbonate chemistry of the southern ocean water must be learned in order to understand the biogeochemical cycle of carbon from the global point of view. Unfortunately, only a few high‐precision carbonate sampling programs have been conducted in the Indian Ocean section of the southern ocean (we know of only seven such stations south of 30°S). As a result, it is difficult to interpret variations in the carbonate chemistry or to calculate anthropogenic CO2 in the Indian Ocean because we do not know the characteristic properties of the water near its origin. Furthermore, the scant data in the southern Indian Ocean were all collected in the summer, and it is uncertain whether the summer data are representative of the mainly winter‐formed deep waters.

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