Dating of a Dome Fuji (Antarctica) shallow ice core by volcanic signal synchronization with B32 and EDML1 chronologies

Abstract

We found extremely good synchronization of volcanic eruption signals between a shallow ice core drilled at Dome Fuji in 2001 (DF01 core) and the B32 shallow ice core from Dronning Maud Land, East Antarctica. We then applied volcanic signature matching to transfer the B32 chronology constructed by annual layer counting to a portion of the 5 DF01 core for which annual layer counting was difficult because of the low precipitation rate. Matching was done by careful comparison of non-sea-salt sulfate (nssSO 2− 4) data, which have a temporal resolution of about 1 yr, between the DF01 and B32 cores. The newly obtained chronology is called DFS1 (Dome Fuji Shallow ice core 1). In total, 31 volcanic eruptions were synchronized from AD 1900 back to AD 187, the earliest 10 volcanic eruption date in the B32 core. The mean accumulation rate between synchronized volcanic horizons of the Dome Fuji core relative to rates at the B32 core drilling site did not differ significantly between these dates, increasing our confidence in this matching approach. We also used the B32-correlated EDML1/EDC3 chronology obtained from the top part of the EPICA Dronning Maud Land (DML) deep ice core to 15 date a portion of the DF01 core. This new chronology, called DFS2 (Dome Fuji Shallow ice core 2), uses the correlations between B32 and EDML1/EDC3 ages to date the DF01 core from AD 1900 back to AD 199; moreover, four volcanic eruption dates from the EDML1/EDC3 chronology were used to date the interval from AD 199 back to AD 1. Because the EDML1/EDC3 ages were determined by adopting the B32 chronology 20 back to AD 1170, DFS1 and DFS2 dates are identical between AD 1170 and 1900. These two methods enabled us to obtain a detailed chronology of the DF01 core, in particular the part before the last millennium, which has been difficult before this. We also present the absolute mean accumulation rates at Dome Fuji between AD 1 and 1900, based on the DFS1 and DFS2 chronologies.