While working on something else, I discovered a slight error in 2 of my files from my recent article you handled (thanks for handling this!). In a supplemental table where I list previously published radiocarbon ages, there was an error in calibrating a few of them. For some of the old marine 14C ages done in the 1960s and 70s, the measurement assumed a delta 13C value of -25 per mille instead of 0 per mille. The result is that there is a 400 year reservoir correction that is essentially “built in” to these measurements. Thus, because the CALIB/IntCAL13 system used a global average/default reservoir correction of 400 year, these two numbers cancel each other out and you can calibrate these old marine samples just using the terrestrial calibration. This is fairly well known and have dealt with this before.  However, during manuscript prep, I re-calibrated all these ages using the IntCAl/MARINE 20 database (instead of IntCAL13) that was published as I was submitting this manuscript. The default reservoir correction in the new calibration is now 550 years instead of 400. Thus, for this handful of ages that need correction, you have to add 400 years to the raw 14C age, and then use the MARINE20 database default reservoir correction of 550 years.
 
So I went ahead and did all this and the newly calibrated ages barely change, <100 years in all cases, and this is all for previously published data, nothing new. None of our interpretations or conclusions change at all. Nonetheless, I’d like to report the “correct” numbers in the supplemental file. In addition, in Figure 1 in the main manuscript, as part of the background, we show the location of the these previous radiocarbon ages and show the rounded calibrated age for the reader. Because of the new calibration a few of these changed by 100 years (rounded) and I’d like to use an updated Figure 1. For example, an old point that was “11.3 ka BP” has changed to “11.2 ka BP”, and two points that were 9.9 ka BP changed to 9.8 ka BP.  Again, this is all linked to that supplemental table, applies to older radiocarbon ages, and doesn’t apply to any new data or interpretations we present.
 
Thanks for your help and let me know if you have any questions.
