Abstract
Plate deformations in the Southeast Asian plate are studied with the use of optical observations of time and latitude at Mizusawa, Tokyo and Irkutsk. Japan, mean values of Mizusawa and Tokyo, and Irkutsk show large mutual variations of about 1 ms in longitude. The longitude variations suggest couplings with variations of the Earth's rotation. A viscous coupling model with a rigid mantle and plates may be possible to explain these couplings.
