Figure 1. (a) DAS map. Dark fiber (Green line) is located beneath Penn State University campus in State College, Pennsylvania (inset, red triangle). Selected channels are indicated for referencing sensors’ location. The blue star indicates the construction site. The red dashed lines divide the campus into three sections. (b) Temporal variations of seismic noise across the DAS channels. The timeline of local conditions is shown above. Note that dates are not continuous and the white space indicates the data gaps due to unexpected power interruptions. Red line marks the abrupt noise change during the implementation of the stay-at-home order. A Clear diurnal pattern shows that signals are mainly from human activities in the daytime.