7 Scientific Note.+ GPS + +, - GPS observations on the Antarctic ice sheet conducted during JARE-.+ Koichiro Doi +, Naoya Imae +, Naoyosi Iwata, and Noritsune Seo -,**- +* 1 ;,**- +, - Abstract: We conducted GPS observations at three sites on the Antarctic ice sheet during wintering of the.+st Japanese Antarctic Research Expedition (JARE-.+). The three sites are N1 (vicinity of coastline), Mizuho Station (,0* km inland on the ice sheet), and YM+1/ (bare ice field near the Yamato Mountains). Continuous data for more than four days were obtained and velocity vectors were determined with reference to the Syowa International GPS Service for Geodynamics (IGS) site using a precise ephemeris. The obtained velocity at N1 was +./ cm/day and the direction was N0* W. At Mizuho Station, the observed velocity was 0 cm/day and the direction was N0* W. These values showed good agreement with previous observations by H. Motoyama et al. (Nankyoku Shiryô, -3, 3., +33/). At YM+1/, continuous observation for more than +* days was carried out;observed vertical and lateral displacements were about + cm. The considerable upward displacement as well as the small lateral displacement supports the meteorite accumulation hypothesis for the Yamato Mountains region. :.+ - N1 YM+1/ GPS N1 N0* W +./ cm day N0* W 0 cm day H. Motoyama et al. Nankyoku Shiryô, -3, 3., +33/ YM+1/ N1+ W *.2 mm day +.+ mm day + National Institute of Polar Research, Kaga +-chome, Itabashi-ku, Tokyo +1-2/+/., Faculty of Science, Yamagata University, +. +,, Kojirakawa-machi, Yamagata 33* 2/0*. - Hydrographic and Oceanographic Department, Japan Coast Guard, Tsukiji, Chuo-ku, Tokyo +*. **./., Vol..2, No.+, 1 +2,,**. Nankyoku Shiryô (Antarctic Record), Vol..2, No.+, 1 +2,,**.,**. National Institute of Polar Research
8 +. synthetic aperture radar: SAR,***.+.+ - global positioning system GPS GPS.+ GPS,. GPS S+0 N1 Mizuho YM+1/ - + GPS, Ashtech Z-FX -* elevation mask +/ - +** AH +,* AH + + N1 +./ km N1.+ Iwata and Imae,,**,. 2 3 - N1,, N1
S.+ Tde U ff@ 4g dehij fk6 GPS Fig. +. 3 ῌ + Rab Location of the observation sites. + ` R abn! Coordinates and observation period of each site. Table +. Observation site N1 Mizuho Station YM+1/ Latitude (S) Longitude (E) Height (m) Observation date 020// +2c -30/+ +c +/241,***4.4,1ῌ/4+,***424+.ῌ24+2,***434+2ῌ34+3 1*0.,,c..0+1 /c,,.24-/,***434,*ῌ34,. 1+0..,+c -/0/..-c,+/14+*,***4++4,*ῌ+,4.,***4+,4+,ῌ+,4+0 9,*** 3,*,..! "# $ % & - ' ($)* +,-. /-/0C ῌ//*0C 12 34 56789:; < =$>? @, ABC DEF G.H IJ + + A 789:;$KL M NOPQR S.+ TUVWXY Z[\] ^Imae et al.,,**,_
10 ῌ ῌ ῌ ῌ, N1 Fig.,. Observation at N1. ῌ - Fig. -. Observation at Mizuho Station. ῌ. YM+1/ Fig... Observation at YM+1/.
.+ GPS 11 GPS 2. -. GPSurvey Ver.,.-/ Trimble IGS International GPS Service for Geodynamics SYOG NGS National Geodetic Survey Web http: //www.ngs.noaa.gov/gps/ GPS.html + +, +, - N1 YM+1/ WGS2. WGS2... / a b c 0 a b c 1 a b c -..+. N1 N1 N0* W +./ cm day S+0 GPS Ootaki and Fujiwara,+332; Motoyama et al., +33/ +.- cm day,* km N1 N1 + -.. 2 3,,..,. N0* W + 0 cm,,./ m yr GPS
12, + N1 + Table,(+). Daily results of baseline analysis between N1 and Syowa Station.,, + Table,(,). Daily results of baseline analysis between Mizuho Station and Syowa Station.
, - YM+1/ + Table,(-). Daily results of baseline analysis between YM+1/ and Syowa Station..+ GPS 13
14 / N1 a b c Fig. /. Distance changes between N1 and Syowa Station. (a) N-S component, (b) E-W component, (c) Height component. Motoyama et al. +33/,, m yr N0- W
.+ GPS 15 0 a b c Fig. 0. Distance changes between Mizuho Station and Syowa Station. (a) N-S component, (b) E-W component, (c) Height component...-. YM+1/ YM+1/ *.2 mm day N1+ W -* cm +.+ mm day *.1 mm day Imae et al.,,**,
16 1 YM+1/ a b c Fig. 1. Distance changes between YM+1/ and Syowa Station. (a) N-S component, (b) E-W component, (c) Height component.
.+ GPS 17 - Table -. Displacement velocity at each site. Table... N1 Displacement velocity solutions at N1 for three epochs. Nagata, +312 + GPS /. - N1 YM+1/ GPS N1 YM+1/ GPS N1 - S+0 +, GPS Motoyama et al. +33/ YM+1/ Imae et al.,,**, Nagata +312 +** m GPS
18 Imae, N., Iwata, N. and Shimoda, Y. (,**,): Search for Antarctic meteorites in the bare ice field around the Yamamto Mountains by JARE-.+. Antarct. Meteorite Res., +/, +,.. Iwata, N. and Imae, N. (,**,): Antarctic micrometeorite collection at a bare ice region near Syowa Station by JARE-.+ in,***. Antarct. Meteorite Res., +/,,/ -1. Motoyama, H., Enomoto, H., Furukawa, T., Kamiyama, K., Shoji, H., Shiraiwa, T., Watanabe, K., Namasu, K. and Ikeda, H. (+33/): Preliminary study of ice flow observation along traverse routes from coast to Dome Fuji, East Antarctica by di#erential GPS method. Nankyoku Shiryô (Antarct. Rec.), -3, 3. 32. Nagata, T. (+312): A possible mechanism of concentration of meteorites within the meteorite ice field in Antarctica. Mem. Natl Inst. Polar Res., Spec. Issue, 2, 1* 3,. Ootaki, O. and Fujiwara, S. (+332): Measurement of ice sheet movement at S+0, East Antarctica using GPS. Polar Geosci., ++, 3 +-.,*** : JERS-+.0.- /,.