[dnawy]

USGS Shakemap intensity is based on the peak ground acceleration (PGA). It has been known that, in some cases, PGA does not correlates well with structural damages. The peak ground velocity (PGV) has better correlation with structural damages [1].

Even so, they are only describing the peak values, it does not describe the ground motion frequency or other ground motion characteristic [4]. It is hard to compress a complex phenomenon into single value.

My colleagues suspect that the soil condition in Bangkok (soft soil and basin) and the distance from the epicenter amplifies long period/low frequency content of earthquake waves, making skycraper to be more vulnerable to damages. Example of basin effect is 1985 Mexico City Earthquake [2] and example of long period effect is the 2011 Tohoku EQ [3]

(Note: Magnitude value would probably be stable, they are based on the energy released by the earth (Moment Magnitude), Intensity is just the on-the-ground observation of the earthquake and it can be subjective.) [1] https://www.cwa.gov.tw/Data/service/hottopic/20191213_SC_New... ; https://www.ncdr.nat.gov.tw/CEOCworkshop/cwb_2.pdf [2] https://en.wikipedia.org/wiki/1985_Mexico_City_earthquake [3] https://en.wikipedia.org/wiki/Long_period_ground_motion [4] https://www.iitk.ac.in/nicee/wcee/article/WCEE2012_5499.pdf