  The Local Cluster Substructure Survey (LoCuSS, Smith et al.) is a systematic
multi-wavelength survey of >100 X-ray luminous galaxy clusters (0.14<z<0.3)
selected from the ROSAT all sky survey. We used data on 37 LoCuSS clusters from
the XMM-Newton archive to investigate the global scaling relations of galaxy
clusters. The scaling relations based solely on the X-ray data obey empirical
self-similarity and reveal no additional evolution beyond the LSS growth. Weak
lensing mass measurements are also available in the literature for 19 of the
clusters with XMM-Newton data. The average of the weak lensing mass to X-ray
based mass ratio is 1.09+/-8, setting the limit of the non-thermal pressure
support to 9+/-8%. The mean of the weak lensing mass to X-ray based mass ratio
of these clusters is ~1 with 31-51% scatter. The scatter in the
mass--observable relations (M-Y_X, M-M_{gas} and M-T) is smaller using X-ray
based masses than using weak lensing masses by a factor of 2. Using the scaled
radius defined by the Y_X profile, we obtain lower scatter in the weak lensing
mass based mass--observable relations. The normalization of the M-Y_X relation
(also M-M_{gas} and M-T relations) using X-ray (weak lensing) mass estimates is
lower than the one from simulations by up to 20% at ~3 sigma (~2 sigma)
significance. Despite the large scatter in the X-ray to lensing comparison, the
agreement between these two completely independent observational methods is an
important step towards controlling astrophysical and measurement systematics in
cosmological scaling relations.
