Introduction to this special section: Southeast Asia

Abstract

This special section on Southeast Asia features geophysical topics that cover several of the magnificent geotectonic provinces of the region. Southeast Asia is the site of the world's largest archipelago, which features more than 20,000 islands extending east to west more than 3500 miles. The extent of the offshore regions of the archipelago is many times greater than its land area. The Sunda Shelf, with its numerous Tertiary basins in the western part of the archipelago, contains areas of India, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, Singapore, the Philippines, Brunei, West Indonesia, and their offshore regions that extend from the Andaman Sea to the Makassar Strait. By contrast, eastern Sunda, with its pre-Tertiary basins, embraces the islands along and north of the Banda Arc, from Sulawesi to western Papua in Indonesia and Timor-Leste and surrounding seas ( Figure 1 ). The most distinguishing tectonic features of the archipelago are related to the collision of the Indo-Australian Plate with the Sunda Shelf and the areas east of it. Numerous volcanoes and earthquake epicenters trace an extensive arc of collision-related subduction zones, which makes this one of the most tectonically active regions in the world. Back-arc and other basins within the stable parts of the Sunda Shelf are the sites of significant hydrocarbon accumulation, primarily within the territorial boundaries of Indonesia and Malaysia.