Based upon solid geological evidence, consisting largely of the analysis of numerous deep core sample from coral reefs, variations in the rates of sea level rise have been reconstructed for the postglacial period. For the early part of the sea level rise that is associated with deglaciation, three major periods of accelerated sea level rise, called meltwater pulses, occurred. They are commonly called meltwater pulse 1A0 for the one between 19,000 and 19,500 calendar years ago; meltwater pulse 1A for the one between 14,600 and 14,300 calendar years ago and meltwater pulse 1B for the one 11,400 and 11,100 calendar years ago. The Younger Dryas occurred after meltwater pulse 1A, a 13.5 m rise over about 290 years, centered at about 14,200 calendar years ago, and before meltwater pulse 1B, a 7.5 m rise over about 160 years, centered at about 11,000 calendar years ago. Finally, not only did the Younger Dryas postdate both all of meltwater pulse 1A and predate all of meltwater pulse 1B, it was a period of significantly-reduced rate of sea level rise relative to the periods of time immediately before and after it.
How many more m was the rise of meltwater pulse 1A compared to meltwater pulse 1B?
6