Schematic drawings of the geodynamic situation in Andaman Sea and Southern Thailand before (A) and
during/after the 26 December 2004 Earthquake (B). The Indian-Australian and the Eurasian Plate with the
smaller Burma Plate (not shown here) were locked and both moved to the East (A), resulting in a
compressional state of the Burma Plate (close spaced shading). Some sinkholes (closed triangles) and
earthquakes (closed circles) occurred in Southern Thailand. With and after the 26 December Earthquake (B)
both plates were unlocked. The Eurasian Plate moved to the West. This caused an extension or crustal
dilatation in the Eurasian Plate (larger spaced shading) with an increase in sinkhole and earthquake
occurrences. The lower figures in (A) and (B) are adopted from Hyndman and Wang 1993.