Figure 12. Relative sea level (RSL) curves for Icy Point (this study)
and Palma Bay (Mann and Streveler, 2008)—two sites separated by the
Fairweather fault. Both sea level curves are tied to the present (0 yr
BP) and defined by shoreline features referenced to the elevation of the
modern shoreline angle, which approximates Mean High Water (MHW). The
greatest contribution to uncertainty in these curves is the timing of
deceleration in the rate of eustatic sea level rise in the early
Holocene, which allowed local processes to exert greater influence on
RSL change at Icy Point. The time when eustatic sea level ceased to be
the dominant control on RSL is best approximated by the age of
abandonment of the Terrace B paleo sea cliff (see text) at 7.4±1.2 ka.
The stair-step pattern of the Icy Point RSL curve (green) reflects
shoreline features on Terrace B interpreted as evidence for repeated
coseismic uplift that contributed to -42.3 ± 2.1 m of RSL change at Icy
Point (RSLΔIP). In contrast, the RSL curve in Palma Bay
(blue) shows a history of +4.1 ± ~1 m of RSL change
(RSLΔPB) in response to fluctuating ice loads in
neighboring Icy Strait and Glacier Bay (Mann and Streveler, 2008). The
tectonic component of RSL change (RSLΔTEC), -46.4 ±2.4
m, is the difference between the two RSL curves separated by the
Fairweather fault (RSLΔTEC = RSLΔIP –
RSLΔPB, Table 4).