\begin{table}%t2
%%\centering

\par
\caption{\label{tab:nickel_vel}Dependence of the maximum nickel velocities (in \kms) 
         in our two-dimensional models with different spatial resolution
         on the width of the polar exclusion cone $\Delta \theta$.}
\begin{tabular}{ccccc}
\hline\hline
           & \multicolumn{4}{c}{\mbox{$\Delta \theta$}} \\
Resolution & $0^\circ$ & $10^\circ$ & $20^\circ$ & $30^\circ$ \\
\hline
15 km  & 3950 & 3350 & 3250 & 3200 \\ 
30 km  & 3800 & 3800 & 3450 & 3400 \\
60 km  & 3600 & 3425 & 3350 & 3350 \\
\hline
\end{tabular}
\end{table}