  We present new measurements of the time variability of intensity, Doppler and
non-thermal velocities in moss in an active region core observed by the EUV
Imaging Spectrometer on Hinode in 2007, June. The measurements are derived from
spectral profiles of the Fe 12 195A line. Using the 2" slit, we repeatedly
scanned 150" by 150" in a few mins. This is the first time it has been possible
to make such velocity measurements in the moss, and the data presented are the
highest cadence spatially resolved maps of moss Doppler and non-thermal
velocities ever obtained in the corona. The observed region produced numerous
C- and M- class flares with several occurring in the core close to the moss.
The magnetic field was therefore clearly changing in the active region core, so
we ought to be able to detect dynamic signatures in the moss if they exist. Our
measurements of moss intensities agree with previous studies in that a less
than 15% variability is seen over a period of 16 hours. Our new measurements of
Doppler and non-thermal velocities reveal no strong flows or motions in the
moss, nor any significant variability in these quantities. The results confirm
that moss at the bases of high temperature coronal loops is heated
quasi-steadily. They also show that quasi-steady heating can contribute
significantly even in the core of a flare productive active region. Such
heating may be impulsive at high frequency, but if so it does not give rise to
large flows or motions.
