Map of the Indian Ocean

Map of the Indian Ocean

The two sheets (1- Physiography; 2- Structural Map) of this Map, were the first in a new series of maps of the CGMW dedicated to the world's oceans. The Indian Ocean map shows the main morphological and structural features of the region, and covers both the land and the seabed. It incorporates the most recent data from marine magnetic anomaly and satellite altimetry campaigns stored in international geophysical databases.

The Physiography map provides a digitised 'fine-grained' image of the morphology of the land and sea surfaces, supplemented by the drawing of selected isobath curves (-200 m, -1000 m, then every 1000 m). In addition to its scientific interest, the aesthetics of this sheet is undeniable. Some 300 active or Holocene volcanoes and about 40 meteorite impact craters are plotted.

Sur la Carte Structurale on a représenté, à terre, les caractéristiques géologiques les plus marquantes : Archéen, Protérozoïque, bassins phanérozoïques; orogenèses paléozoïques, mésozoïques, et cénozoïques; accidents majeurs, grandes failles de décrochement, fronts de chevauchement. En raison de son environnement spécifique (calotte glaciaire géante) l’Antarctique a reçu un traitement cartographique approprié. Pour les zones sous-marines, l’accent a été mis sur la structuration de la croûte océanique : âges chronostratigraphiques, axes d’accrétion océanique, failles transformantes, zones de subduction, reliefs de croûte anormale (rides asismiques, plateaux océaniques, …).

Sont figurés en outre, la localisation de points de mesure (picks) des anomalies magnétiques standard (chron), les vecteurs de divergence (dorsales d’accrétion) et de convergence (zones de subduction), l’épaisseur des sédiments recouvrant le socle océanique, et la zone de compression qui affecte la croûte océanique entre le bloc continental de l’Inde et son homologue australien.

Map of the Indian Ocean

Earthquakes of magnitude = 5.0 have been plotted, both onshore and offshore, with a figure depending on their strength and depth at focus.

In the box, a geodynamic sketch summarises the main characteristics of plate tectonics in the mapped area; it highlights in particular the imprint of the Reunion hotspot on the lithosphere, which has been in motion since about 65 Ma, the time of the gigantic outpouring of basalts from the Deccan traps. After the original edition ran out, a reduced version of the two maps at a scale of 1:40 000 000 was published in October 2013.

Explanatory notes to download here

Map of the Indian Ocean