Adam Pascale from the Seismology Research Centre recently shared this animation (click on controls bottom right for High Quality and Full Screen views):

… it’s from a building in the Philippines about 130km (hypocentral distance) from a magnitude 6.1 earthquake in April 2019. There were three high resolution strong motion accelerographs (SMA-HR) installed in the building according to local government regulations for structural monitoring – one in the lowest basement, one in the middle floor, and one below roof level.

My colleague and fellow SRC seismologist Santi (Juan Santiago Velasquez) has done a great job at visualising this data in an animation where the horizontal motion of each SMA-HR has been superimposed on top of each other to see the relative movement of each monitoring point. Hopefully you can view the attached video file.

The blue dot represents the SMA-HR in the lowest basement (6 levels below ground level), the green dot the instrument on the 9th floor, and the red dot the instrument on the 18th floor. The data has been converted to displacement and the plotting scale is millimetres, so we’re not talking a lot of motion, but it’s still very clear because of the use of low noise sensors. These dancing dots are an accessible and entertaining way to use seismic data to visualise the synchronised movement of a building during an earthquake.