Tectonic settings of Sumatra, Indonesia
Dark red lines show Sumatran fault zone (after Sieh and Natawidjaja, 2000); red line with teeth shows the Sunda trench, source of the 2004 M9.1 Sumatra-Andaman earthquake. Thin green lines show Plio-Pleistocene fold axes that may represent active thrusting. Orange shows Tertiary basins containing oil and gas (after Doust and Noble, 2008). Black arrows show relative plate movement.