Recordings made at five broadband seismometers, deployed in central London during the summer of
2015, reveal the wideband nature (periods, T, of between 0.01 and 100 s) of anthropogenic noise in
a busy urban environment. Temporal variations of power spectral density measurements suggest
transportation sources generate the majority of the noise wavefield across the entire wideband, except
at the secondary microseismic peak (2< T <6 s). The effect of road traffic is greatest at short periods
(T <0.4 s) where acceleration noise powers are ∼20dB larger than the New High Noise Model; at
T =0.1 s daytime root-mean-square acceleration amplitudes are 1000 times higher in central London
than at an observatory station in Eskdalemuir, Scotland. Overground railways generate observable
signals both at short periods (T <0.3 s), which are recorded in close proximity to the tracks, and at
very long periods (T >20 s) which are recorded across the city. We record a unique set of signals 30m
above a subway (London Underground) tunnel interpreted as a short-period dynamic component, a
quasi-static response to the train moving underneath the instrument, and a very long period (T>30 s)
response to air movement around the tunnel network. A low-velocity clay and sand overburden tens
of metres thick is shown to amplify the horizontal component wavefield at T ∼1 s, consistent with
properties of the London subsurface derived from engineering investigations. We provide tabulated
median power spectral density values for all stations, to facilitate comparison with any future urban
seismic deployments.