OBSERVATIONS OF LAND EMERGENCE IN AUKE BAY, SOUTHEAST ALASKA

In recent years there has been notable land emergence throughout Southeast Alaska. Post-Little Ice Age (LIA) glacial rebound in Southeast Alaska has been measured using tide gage analysis, GPS and dendrochronology. It has been observed that over time benchmarks in Northern SE Alaska are increasing in elevation relative to mean sea level. Analysis of the continuous sea level record at station 9452210, Juneau, Gastineau Channel, Stephens Passage, AK has shown a 1.3 cm/yr rate of emergence since 1936. This emergence is believed to be a part of a greater regional uplift focused at Glacier Bay National Park, Southeast Alaska. A previous observation of uplift in Auke Bay, approximately 10 miles north of Juneau, Alaska has shown a 1.9 cm/yr rate of emergence. However, our analysis of the National Ocean Service (NOS) record suggests a lower rate of emergence, 1.25 cm/yr. Preliminary observations from spring 2000 also suggest a lower rate of emergence, 1.22 cm/yr since 1979. Modeled after an ongoing study of post-LIA glacial rebound in Northern SE Alaska, we installed a temporary tide gage to record mean sea level relative to a nearby NOS benchmark in Auke Bay, Alaska. Our temporary tide gage is currently on site for a 60 day period to verify our previous results. Our recorded mean sea level data is adjusted by concurrent variances in mean sea level recorded at station 9452210, Juneau, Gastineau Channel, Stephens Passage, AK to remove oceanographic effects. Our benchmark elevation relative mean sea level is compared to historical benchmark elevations relative to mean sea level to calculate a regional uplift rate.