Cosmogenic ²⁶Al/¹⁰Be surface production ratio in Greenland

The assumed value for the cosmogenic 26 Al/ 10 Be surface production rate ratio in quartz is an important parameter for studies investigating the burial or subaerial erosion of long‐lived surfaces and sediments. Recent models and data suggest that the production ratio is spatially variable and may be greater than originally thought. Here we present measured 26 Al/ 10 Be ratios for 24 continuously exposed bedrock and boulder surfaces spanning ~61–77°N in Greenland. Empirical measurements, such as ours, include nuclides produced predominately by neutron‐induced spallation with percent‐level contributions by muon interactions. The slope of a York regression line fit to our data is 7.3 ± 0.3 (1 σ ), suggesting that the 26 Al/ 10 Be surface production ratio exceeds the commonly used value of 6.75, at least in the Arctic. A higher 26 Al/ 10 Be production ratio has implications for multinuclide cosmogenic isotope studies because it results in greater modeled burial durations and erosion rates.