Jökull - 01.06.2000, Blaðsíða 15

Ice-thickness measurements on Sólheimajökull
Tablel. Sólheimajökull Ice Radar Survey
point meas. time Qís.) ice thickn. (m) location UTM, Zone 27 5,70 surface elev. m.a.s.l bed elev. m.a.s.l point meas. time (jtts.) ice thickn. (m) location UTM, Zone 27 5,70 surface elev. m.a.s.l bed elev. m.a.s.l
Outlet Glacier X-Section 1
1 1,96 177 88 200, 55 280 1220 1043 1 3,56 312 84 086,48 830 540 228
2 3,16 278 88 080, 54 800 1180 902 2 4,04 353 84 385, 49 890 550 197
3 3,28 288 87 760, 54 600 1160 872 3 5,00 433 84 331,49 077 559 126
4 4,08 356 87 455, 54 415 1120 764 4 4,48 390 84 540,49 042 555 165
5 4,12 359 86 946, 54 137 1080 721 5 3,64 319 84 701,49 009 545 226
6 4,52 393 86 552, 53 950 1055 662
7 4,36 379 86 262, 53 723 1020 641 X-Section 2
8 3,48 305 85 790, 53 494 975 670 1 2,88 255 82 271,47 046 360 105
9 3,64 319 85 517, 53 245 955 636 2 3,80 332 82 246, 46 845 343 11
10 3,44 302 85 225, 52 958 915 613 3 3,02 267 82 368, 46 689 347 80
11 3,40 299 84 965, 52 682 860 561 4 2,22 199 82 379,46 539 332 133
12 3,52 309 84 990, 52 343 820 511 5 1,22 114 82 360,46 360 312 198
13 3,76 329 84 998,51 926 780 451
14 3,80 332 85 026, 51 516 730 398 Ice Cap
15 3,64 319 84 842,51 169 705 386 1 2,96 261 90 610,53 135 1370 1109
16 3,72 326 84 892, 50 577 680 354 2 2,00 180 90 477,53 322 1368 1188
17 3,92 342 84 600, 50 456 650 308 3 2,76 245 90 294, 53 508 1360 1115
18 4,08 356 84 587, 50 200 630 274 4 2,80 248 90 132,53 640 1359 1111
19 4,44 386 84 488, 49 997 620 234 5 3,00 265 89 896,53 817 1358 1093
20 4,76 413 84 490, 49 796 610 197 6 3,32 292 89 946, 53 804 1350 1058
21 4,54 395 84 459, 49 576 595 200 7 3,12 275 89 549,53 903 1348 1073
22 5,00 433 84 457, 49 234 580 147 8 3,00 265 89 287,53 896 1343 1078
23 5,00 433 84,331,49 077 559 126 9 3,20 282 89 032, 53 940 1338 1056
24 4,88 423 84 312, 48 770 549 126 10 3,24 285 88 699,54 094 1336 1051
25 4,56 396 83 919,48 106 512 116 11 2,00 180 88 492,53 971 1332 1152
26 4,96 430 83 860, 48 142 490 60 12 3,08 272 88 699, 54 094 1328 1056
27 4,80 416 83 375, 47 966 482 66 13 3,12 275 88 443, 54 702 1320 1045
28 4,40 383 83 583, 47 707 428 45 14 3,52 309 90 057,55 982 1369 1060
29 4,08 356 83 342, 47 560 428 72 15 3,30 290 90 167,54 722 1366 1076
30 4,28 373 83 164,47 373 419 46 16 3,28 288 89 300, 54 912 1335 1047
31 4,20 366 82 971,47 152 405 39 17 3,52 309 89 270,54 950 1330 1021
32 4,04 353 82 717,47 030 379 26 18 3,40 299 88 620, 55 186 1320 1021
33 3,78 331 82 491,46 877 362 31 19 3,40 299 88 032, 54 719 1316 1017
34 3,80 332 82 245, 46 845 343 11 20 3,40 299 88 667,54 491 1303 1004
35 2,72 241 81 676, 46 117 322 81 21 3,44 302 88 298, 54 733 1313 1011
36 1,54 141 81 442, 46 663 266 125 22 3,40 299 87 765, 54 674 1268 969
37 1,42 131 81 210, 46 512 246 115
38 0,68 67 80 919, 46 119 140 73
39 0,50 50 80 851,46 154 135 85
but the difference increases markedly on Sólheima-
jökull. Here, Lawler et al. (1996) estimated ice
thickness based on the surface slope, and a basal yield
stress of 1 bar, assuming perfect plasticity (Paterson,
1994). Our ice thickness measurements differed by up
to 200 m (>50%) from the theoretical estimates. The
near parabolic profile of the sub-glacial trough contr-
asts strongly with nearby sub-aerial canyons that have
formed predominantly as a result of jökulhlaups from
the Katla volcano. This suggests that glacial erosion
has been more important than fluvial erosion in trough
development. Further, the predictable crevasse patt-
erns, lack of surface bulges or folded moraines and
the gently declining ice surface profile suggests that
JÖKULLNo. 48 13