Improve the consistency of the following text:
The total volume of the basins is equivalent to a depth of 1.2 meters spread evenly over the Martian surface. This amount is a small fraction of the current water ice stores on Martian.
The total volume of the basins is equivalent to a depth of 1.2 meters spread evenly over the Martian surface. However, this amount is a small fraction of the current water ice stores on Mars.