Table 1 Observational data and calibrated radiocarbon ages.

Reference	Site name	Latitude	Longitude	Material	Marker depth (m)	Raw ¹⁴C age (years)	Raw age error	ΔR	ΔR error	Calendar year (before present)	1σ− years	1σ+ years	Calibration curve
Jakobsson et al. (4)	4PC-1	72.8	175.7	Mollusc	124.07	10,200	30	250	200	10,900	230	510	Marine13
Keigwin et al. (5)	JPC02	67.4	165.6	Elphidium excavatum	53.455	10,900	140	250	200	11,950	350	490	Marine13
Hill and Driscoll (6)	VBC03*	70.7	165.4	Marine bivalve (Portlandia)	60.42	11,500	765	250	200	12,590	1120	910	Marine13
	JPC10	70.8	165.5	Marine bivalve	59.2	10,200	55	250	200	10,910	240	250	Marine13
Elias et al. (12)	85-69	70	165.7	Screened peat	44.95	11,000	60	0	0	12,870	90	80	Intcal13
Dyke and Savelle (8)				Bowhead whale bone		10,210	70	320	50	10,850	140	130	Marine13
Dyke et al. (9)				Macoma balthica		11,400	100	320	50	12,600	90	110	Marine13
England and Furze (7)				Cyrtodaria kurriana		12,380	110	320	50	13,520	140	130	Marine13
England and Furze (7)				C. kurriana		12,170	25	320	50	13,320	60	60	Marine13
England and Furze (7)				C. kurriana		11,800	70	320	50	12,960	110	121	Marine13

*Portlandia arctica raw ¹⁴C age reflects correction (800 ± 700 years subtracted from published raw ¹⁴C age).