1. Where is the NW Corner of Stable North America
Jeff Freymueller and Chris Larsen
Geophysical Institute, Univ.of Alaska
Stephane Mazzotti, GSC

3. Is There Any Stable North America on Preceding Slide?
Siberia east of Cherskiy Range appears to lie on North American plate
But most of Alaska and Northern Cordillera in Canada is (geologically) mobile relative to stable North America
Strong time-dependent signal from large earthquakes
Rapid uplift from regional ice loss

4. NOAM
NOAM

5. Blue: no ocean loading model
Red: ocean loading corrected

6. GPS uplift rates 76 sites, 5 years of campaign measurements
Peak uplift rates mm/yr
Average  = 1.8 mm/yr Max  = 4 mm/yr

7. Greatly Uplifted

9. ~5000 km to “stable” region defined geodetically
A Long Lever Arm!
~2500 Fairbanks to Seattle
~5000 km to “stable” region defined geodetically

11. Work to Date Initial comparison of UAF and PGC solutions.
Are there sites that geodesy tells us are stable?
Investigation of error sources/noise sources in out existing time series
Ocean tidal loading mismodeling is probably the dominant error source

13. Ocean Tidal Loading Tidal range in Gulf of Alaska extremely large
Comparison done on 6 months of data
With and without ocean tidal loading modeling
Load model computed using SPOTL, based on TPXO.2 + CSR3.0
Dominant peak is at 14 day period, aliased tidal loading

14. Initial Conclusions
Don’t forget far NW sites as part of frame definition
Bilibino (BILI)
Barrow? (SG27)
Non-secular components are particularly strong in north country