| Summary: | After the M<sub>w</sub> 9.3 Sumatra-Andaman Earthquake on 26 December 2004, a temporary broadband seismic station was set up at the Khao Chang Telecommunication Station in Phang nga Province, Southern Thailand, in order to monitor aftershocks in an area bounded by 0<sup>o</sup>-20<sup>o</sup> N, and 90<sup>o</sup>-100<sup>o</sup> E. Altogether 98 events were identified during the study period from 1<sup>st</sup> to 12<sup>th</sup> January 2005; but six of these events are not listed in the catalog of the United States Geological Survey (USGS/ NEIC). Body wave magnitudes (m<sub>b</sub>) and moment magnitudes (M<sub>w</sub>) of the events were determined and compared with USGS magnitudes. For m<sub>b</sub>, the PSU values are 0.215 higher than the USGS values, whereas for M<sub>w</sub>, the PSU values are 0.268 lower than the USGS values. Differences in m<sub>b</sub> may result from differences in time windows chosen for the maximum amplitude determination, or from accuracy of the Q-value. Differences in M<sub>w</sub> may result from assumptions made on velocity, attenuation and determination of the low-frequency part of the seismic spectrum. However, these differences are comparatively small considering that the USGS data are network values whereas the PSU data are from a single station.
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