Microplate · oceanic and continental crust

Burma Plate

Also called the Burma Microplate

The Burma Plate is a long, narrow microplate that runs from northern Sumatra through the Andaman and Nicobar Islands. The Indian Plate sinks beneath its western edge, which ruptured in the M9.1 Sumatra-Andaman earthquake of 2004.

Area
515,365 km²
Share of Earth
0.1%
Size rank
27 of 52
Avg boundary speed
3.4 cm/yr
Map showing the location of the Burma Plate and its neighbors Burma Open on interactive map

Boundaries of the Burma Plate

4,032 km of boundary in total: 43% convergent, 27% divergent, 30% transform. Speeds are relative motion between the two plates, from the PB2002 model.

Neighboring plate Boundary type Main features Shared length Relative speed
Indian Plate Convergent Subduction zone, Continental transform fault 2,005 km 1.0-5.1 cm/yr
Sunda Plate Divergent Continental rift, Continental transform fault 1,783 km 2.8-5.7 cm/yr
Australian Plate Convergent Subduction zone 162 km 4.9-5.3 cm/yr
Eurasian Plate Convergent Continental collision zone 82 km 5.0-5.1 cm/yr

Where it is and what it carries

The Burma Plate, also called the Burma Microplate, is a slim strip of crust about 515,000 km² in area. It runs from the northern tip of Sumatra and the island of Simeulue north through the Nicobar and Andaman Islands into the Andaman Sea. Its only land is small: the Andaman and Nicobar Islands of India and parts of northern Sumatra and nearby islands in Indonesia.

Despite its name, almost none of Myanmar lies on this plate in PB2002. The dataset places western Myanmar on the Indian Plate and the rest on the Eurasian Plate and Sunda Plate.

What happens at its edges

The western edge is the Andaman Trench and the northern part of the Sunda Trench. Here the Indian Plate sinks beneath the Burma Plate along about 2,000 km of boundary, at an average of about 2.5 cm/yr. In places the rate reaches about 5.1 cm/yr. The Indian Plate arrives at a slant, so part of its motion is taken up by sideways sliding inside the overriding plate.

The eastern edge, about 1,780 km long, separates the plate from the Sunda Plate. It combines the Andaman Sea spreading center, continental rifts and strike-slip faults, with relative motion of about 4.3 cm/yr. That spreading opens the Andaman Sea as the Burma Plate moves north.

At its southern tip, the plate meets the Australian Plate along 162 km of subduction zone at about 5.1 cm/yr. A tiny 82 km collision boundary touches the Eurasian Plate in the north.

Earthquakes and volcanoes

The Burma Plate has had 31 earthquakes of magnitude 6.5 or larger since 1900, and 2 reached magnitude 8. The largest by far is the 2004 Sumatra-Andaman earthquake (M9.1), one of the largest ever recorded. The 1907 Sumatra earthquake (M8.2) struck near Simeulue and also caused a tsunami; islanders kept stories of it alive, and that memory helped many of them escape in 2004.

Other large events include a M7.96 in 1941 near the Andaman Islands, a M7.5 in 2009 north of the Andamans, a M7.5 near the Nicobar Islands in 2010, and M7.4 quakes near Simeulue in 2002 and 2008.

The plate has 1 volcano in the dataset, Barren Island, the only confirmed active volcano in India. It rises from the Andaman Sea east of the Andaman Islands, above the slab of the sinking Indian Plate.

Countries on the Burma Plate

Share of each country's land area that lies on this plate.

Largest earthquakes on the Burma Plate

31 earthquakes of magnitude 6.5 or more since 1900 had their epicenter on this plate, 2 of them magnitude 8 or larger. Data: USGS.

Volcanoes on the Burma Plate

The Smithsonian Global Volcanism Program lists 1 Holocene volcanoes on this plate. The most recently active:

See all volcanoes on the live map

Frequently asked questions

What caused the 2004 Indian Ocean tsunami?

On 26 December 2004, the boundary between the Indian Plate and the Burma Plate slipped in a M9.1 earthquake. The rupture began off northern Sumatra and spread north along the Andaman and Nicobar Islands. The sudden lift of the seafloor pushed up the water above it, and the tsunami killed more than 200,000 people around the Indian Ocean.

Is Barren Island an active volcano?

Yes. Barren Island in the Andaman Sea is the only confirmed active volcano in India. It sits on the Burma Plate above the sinking Indian Plate and has erupted repeatedly since 1991, after a long quiet period.

Is the Burma Plate a separate plate?

PB2002 and many other studies treat it as a microplate, because oblique subduction along the Andaman Trench has cut off a narrow forearc sliver that moves north faster than the Sunda Plate behind it. Its exact limits differ between models, especially in the north near Myanmar, and some researchers treat it as part of a wider Sunda deformation zone.

How big is the Burma Plate?

The Burma Plate covers about 515,365 km² (198,983 sq mi), roughly 0.1% of Earth's surface. That makes it the 27th largest of the 52 plates in the PB2002 model.

How fast does the Burma Plate move?

Measured against its neighbors, the Burma Plate moves at an average of 3.4 cm/yr (1.3 in/yr) along its boundaries. The fastest motion is against the Sunda Plate, where relative speeds reach 5.7 cm/yr on a divergent boundary.

What countries are on the Burma Plate?

Countries partly on it: Indonesia and India. Shares are measured by land area using Natural Earth outlines.

What plates border the Burma Plate?

The Burma Plate shares boundaries with 4 plates: the Indian Plate (convergent), the Sunda Plate (divergent), the Australian Plate (convergent), the Eurasian Plate (convergent).

All 52 tectonic plates