Poster of the Sumbawa, Indonesia Earthquakes of 08 November 2009 - Magnitude 6.7

Tectonic Summary

The November 8th, 2009 earthquake in the Sumbawa region of Indonesia occurred as a result of thrust faulting on or near a microplate boundary within the Sunda plate. Eastern Indonesia is characterized by complex tectonics in which motions of numerous small plates are accommodating large-scale convergence between the Australian and Sunda plates. In the region of today's earthquake, the Australian plate moves northeastwards with respect to the Sunda plate at a rate of approximately 75 mm/yr. The convergence across this plate boundary has caused two oppositely oriented thrust zones; in the south, Australian plate subducts beneath Sunda towards the north at the Java Trench, while on the northern side of the eastern Sunda Arc near the location of today's earthquake, oceanic crust of the Flores Basin subducts to the south along the Flores Thrust.

Earthquakes are fairly common in the region of this event, where 10 events of a similar size to this earthquake have occurred in the last decade. In December 1992, a large M7.8 earthquake occurred approximately 250km to the east of this event, causing over 2,500 fatalities and leaving 90,000 homeless.


Thumbnail image of poster.


The posters may be downloaded for viewing or for printing on a color plotter. Adobe PDF (.pdf) format files are provided. Adobe Acrobat 6.0 or higher is required for viewing the PDF file on a computer monitor and for printing the PDF map graphic.

Attention MAC users: If you have problems viewing the pdf files, please download the pdf file and view it in the lastest verion of Adobe Acrobat.