We recalculated 10Be ages from prior studies on tropical glacier fluctuations using the same methodology described above for the Rwenzori 10Be ages. We provide a brief review of the sites and samples from prior studies within the Supplementary Materials of this manuscript. We used the St scaling scheme (2325) for calculating the 10Be ages from prior work, but note that the differences in 10Be ages calculated using the Lm (51) and LSDn (52) scaling schemes are similar to those for the Rwenzori (see tables S1 and S4).

For the purpose of making the most direct comparisons possible in the discussion of the paper, we chose to include only prior work that used 10Be dating to develop glacial chronologies. Therefore, we did not include prior studies that used radiocarbon dating of organic material associated with moraines or surface exposure dating of moraines using other cosmogenic nuclides such as 36Cl and 3He. However, we note that these additional data neither alter nor counter our broader interpretations.

With the recalculated 10Be ages from prior studies in the tropics, we assigned moraine ages at sites using the following methodology. First, we excluded 10Be ages identified as outliers by the original authors. We also excluded 10Be ages that were not from moraines (i.e., 10Be ages of bedrock surfaces or boulders on bedrock surfaces). We then plotted the locations of 10Be ages in Google Earth and evaluated their glacial geologic contexts. We checked these locations using the original published maps of 10Be ages and glacial geomorphology to ensure that samples plotted correctly as reported in the prior studies. We assigned each sample to a moraine based on the original authors’ interpretations. However, where authors grouped 10Be ages of multiple landforms into a single mean age or moraine group, we attempted to assign 10Be ages to individual moraines using Google Earth. Once each 10Be age was assigned to a moraine, we calculated the mean age of the moraine. Descriptions of the recalculated 10Be datasets and assigned moraine ages are presented in the Supplementary Materials (see the “Tropical 10Be Site Descriptions” section). Because our study focuses on the LGM and the onset of the last deglaciation, we excluded 10Be ages >40 ka and mean moraine ages >30 ka, as well as 10Be ages <17 ka from prior studies.

Where possible for prior studies, we also assessed whether individual moraines mark the onset of recession from or from near the LGM maximum position of a given glacier. This was not always possible to determine because, at some sites, only lateral, composite moraines are dated. We detail these classifications in the Supplementary Materials. All recalculated 10Be ages and associated data are shown in table S4.

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