Jökull - 01.01.2005, Blaðsíða 159

The 2003 NW-Mýrdalsjökull Survey
0 500 1000 1500 2000 2500 3000 3500 4000
0
500
1000
1500
2000
2500
3000
3500
4000
Easting (m)
N
or
th
in
g
(m
) 975
975
1000
1000
10
25
1050
1050
1075
1075

Figure 6. Surface topography (contour lines in m a.s.l.) from air-pressure records and GPS points, shaded bed
relief (blue-to-red, see Fig. 8), and measured displacements. The displacements are calculated from point
positions in April and September. – Yfirborð (hæðarlínur) fengið frá þrýstingsmælingum og GPS-punktum,
botn (litaskali, blár til rauður) og mældar færslur á stikum. Færslan er reiknuð útfrá staðsetningu í apríl og
september.
tion (Trimble 5700) failed after 2 days, the others ran
for 14 and 16 days, respectively.
MD00 moved at 33 m a−1 during the 2 days it was
recording, at an angle of 20◦W of N. MD11 (Figure
9) moved at 24 m a−1, at an angle of 16◦W of N, and
MD12 moved at 22 m a−1 and 19◦W of N (Table 1).
Horizontal and vertical displacements
The horizontal displacements from April to Septem-
ber were between ∼12 m to 21 m, yielding velocities
from 29.5 m a−1 to 54 m a−1. Displacement errors
(Table 2) refer to the error given for the solution el-
lipse (major and minor axes always being equal) in
GPS Pathfinder for the September measurements.
Table 1. Continuous GPS measurements April 22nd
– May 7th, 2003. – Samfelldar GPS-mælingar, 22.
apríl – 7. maí.
Station Time Velocity Direction
(d) (m a−1) ◦
MD00 2 33 20
MD11 14 24 16
MD12 16 22 19
All points moved faster during the peak summer,
May–September, than for the period April to May,
although the data series is quite short for the spring
period. The biggest difference in velocity was ob-
served at MD11, from 24 m a−1 in April to 54 m
JÖKULL No. 55, 2005 159