What does mm year-1 mean?

Question

"Future climate change and estimated sea level rise on Indian coastal zone Past observations on the mean sea level along the Indian coast indicate a long-term rising trend of about 1.0 mm year -1 on an annual mean basis. "

^ what does mm year-1 mean?

thanks

Answer 1

It means millimeters per year.  See, if you were writing millimeters per year in an equation, you'd write it mm/year.  And 1/x is the same as x^-1, so you could also write it as mm * year^-1.  It's confusing and I wish people wouldn't do it, but it is technically correct.