Physics Colloquium, Lukas Wacker, ETH Zürich
|When:||Th 13-06-2019 16:00 - 17:00|
|Where:||FSE Building 5111.0080|
Annually resolved atmospheric radiocarbon concentrations from tree-ring records
|Date:||13 June 2019|
|Start:||16:00 (Doors open and coffee available at 15:30)|
The present radiocarbon (14C) calibration curve (IntCal13) is primarily based on tree ring data measured by decay counting with a temporal resolution of 10 years over the Holocene. Only during the period from 1510 to 1950 CE are measurements at annual resolution included. Two new annually resolved high-precision 14C record will be presented. One record on European oak covers the last 1000 years and one complementary pine record covers the Younger Dryas time period, a time of abrupt cooling around 12 500 BP.
The new records clearly show more fine structure compared to the present calibration curve and consequently will define a new more precise and accurate future calibration curve with higher temporal resolution. In addition, the new 14C records serve can be used the reconstruction of past solar activity. The implications of the two new records will be discussed.