Hello, any one knows what the following stand for? Ns(cm), Ew(cm),Ud(cm),SigmaNs(cm),Sigma-ew(cm),Sigma-Ud(cm)

Question

JoshuaBixby · Answer

Although referring to earthquakes and not subsidence, the same abbreviations are used:

Peak ground acceleration - Wikipedia

During an earthquake, ground acceleration is measured in three directions: vertically (V or UD, for up-down) and two perpendicular horizontal directions (H1 and H2), often north–south (NS) and east–west (EW).

Sigma is the uncertainty around the value.