page 3 The unnumbered equation on line 35 contains an error. There are two things that need to be changed,

(1)
replace
"...one would put $\eta = B|\sigma|^{1-n}/2$, where $n$ and $B$ are the usual exponent and coefficient in Glen’s law, and $\sigma$ is the usual second invariant of the stress tensor,"
on page 3 line 32 with
"...one would put $\eta = B|\tau|^{1-n}/2$, where $n$ and $B$ are the usual exponent and coefficient in Glen’s law, and $\tau$ is the usual second invariant of the deviatoric stress tensor,"

and

(2)
replace the unnumbered equation on page 3 line 35 with
$$ \tau = \sqrt{(\sigma_{ij} - \sigma_{kk}\delta_{ij}/3)(\sigma_{ij} - \sigma_{kk}\delta_{ij}/3)/2} $$

(NOTE: This has no implications for the remainder of hte paper, which 
simply uses a constant $\eta$)




Justification for the editor. The current statement leading up to the unnumbered equation on page 3, line 36 implies that viscosity is a function of the second invariant of the full Cauchy stress sigma_{ij}. 
That is, however, at variance with the usual rheology for viscous flow in ice, for which viscosity is a function of the second invariant of
*deviatoric* stress (as in Glen's law). My request is to (1) change notation from sigma to tau for that invariant (and to refer to it as an invariant of the deviatoric stress) and (2) to give the correct formula for it.


