Updated absolute gravity rate of change associated with glacial isostatic adjustment in Southeast Alaska and its utilization for rheological parameter estimation

Earth, Planets and Space

Table 1 Parameters of AG points (Sun et al., 2010) and their nearest GNSS stations

AG point
Name	EGAN	MGVC	GBCL	RUSG	HNSG	BRMC
Latitude [deg]	58.38534	58.41736	58.45462	58.90639	59.23186	60.00183
Longitude [deg]	−134.64002	−134.54617	−135.87488	−136.78908	−135.45977	−136.85511
Elevation [m]	38.0	8.0	21.0	10.0	21.0	840.0
Nominal air pressure [hPa]	1008.69	1012.29	1010.73	1012.05	1010.73	916.33
Gravity gradient [\(\upmu\)Gal/cm]	−2.734	−2.045^a	−3.099	−3.468	−3.093	−2.910
		−2.364^b
Distance to nearest glacier^c [km]	7.37	1.46	30.82	6.81	11.56	31.09
Continuous GNSS station
Name	AB50	AB50	GUS0^d	QUIC	AB44	MDFC
Data analyst	UNAVCO	UNAVCO	UNAVCO	NGL^e	UNAVCO	NGL
Latitude [deg]	58.41678	58.41678	58.41776	58.90856	59.52804	60.12182
Longitude [deg]	−134.54530	−134.54530	−135.69705	−136.58682	−135.22830	−136.95833
Elipsoidal height [m]	51.6	51.6	19.9	23.8	304.2	897.0
Distance from AG point [km]	6.53	0.08	11.13	11.61	35.42	14.51

^a The gravity gradient value at the old AG point in 2006–2008 (Sun et al., 2010).
^b The gravity gradient value at the new AG point in 2012–2015. During the AG campaign measurement at MGVC in 2012, we observed the gravity difference between 0.0 and 100.0 cm heights from the new AG point using the LaCoste & Romberg’s G578 relative gravimeter by ten times repeatedly, and determined the gravity gradient value by averaging the observed gravity difference values.
^c The 3-D distances from each AG point to the nearest glacier using the PDIM model (UAF07, Larsen et al. 2007).
^d Because the GNSS station of GUS2 was replaced to GUS6 on 20 June 2008, we named a hypothetical GNSS station GUS0 and created its continuous time series from those collected at GUS2 and GUS6 by removing coordinate steps due to the relocation of the GNSS station.
^e Nevada Geodetic Laboratory (NGL).