Jökull


Jökull - 01.12.1984, Page 61

Jökull - 01.12.1984, Page 61
Fig. 4. The photo shows a branch of the Lakagígar 1783 A. D. and Eldgjá 934 A. D. lavas, south of Eldmessu- tangi. The Lakagígar lava stopped here (foreground), while the Eldgjá lava pro- ceeded further (seen grassgrown and with pseudocraters). Mynd 4. Myndin sýnir Skaftárelda- hraunið frá 1783 og Eldgjárhraunið frá 934 sunnan Eld- messutanga. In 1983 it will be 200 years since the Lakagígar eruption took place and one may speculate if such an event is likely to happen in the near future! There is at least one similar event on Iceland, which can be identified in the Greenland Ice Sheet — the Eldgjá eruption around 934 A.D., so it is not a very frequent phenomenon. The Eldgjá eruption took place close to the region of the Lakagígar eruption and I remember my own fascination, when a few years ago I saw these two lava streams; the one on top of the other, both visible at certain places, where the Lakagígar lava had stopped its advance, while the Eldgjá íava had run further. The lavas are today moss- or grassgrown and one can almost tell the difference in eruption dates by the character of their green “blankets”. The Eldgjá eruption In Fig. 4 outliers of the Lakagígar and Eldgjá lavas are seen; the photo shows a location south of Eldmessutangi, where part of the Lakagígar lava flow stopped; at this branch the older Eldgjá flow did proceed further. A characteristic feature in the not overrun Eldgjá lava is its almost “Etruscan tomb-like”, pseudocraters (seen as grass-grown mounds on the photo). Recent evidence, (Larsen 1979), indicates, that the Eldgjá eruption took place after Landnam, but not later than 950 (Thorarinsson personal communication, 1977). The finding of the Eldgjá signal in the Green- land Ice Sheet originated in a kind of “ping- -pong” letters between me and Thorarinsson, where some misunderstandings, preliminary results and new findings resulted in the final dating of the Eldgjá eruption to 934 ± 2 years by means of the Créte acidity record. It is an episode in my working with ice cores, which I remember with great affection. There are several interesting features about the Eldgjá fallout on the ice sheet, which differ from the Lakagígar event. First of all the Eldgjá acid deposition took place over 3 years, Fig 5, and shows a maximum fallout in the winter of 934— 935. The Créte record is the most ideal of the existing records; also with respect to dating. It is not unusual, that stratospheric fallout is high in the winter time, this was e.g. the case for the Tambora fallout (Hammer et al. 1980), but in the case of Eldgjá it points to a rather violent and JÖKULL 34. ÁR 59
Page 1
Page 2
Page 3
Page 4
Page 5
Page 6
Page 7
Page 8
Page 9
Page 10
Page 11
Page 12
Page 13
Page 14
Page 15
Page 16
Page 17
Page 18
Page 19
Page 20
Page 21
Page 22
Page 23
Page 24
Page 25
Page 26
Page 27
Page 28
Page 29
Page 30
Page 31
Page 32
Page 33
Page 34
Page 35
Page 36
Page 37
Page 38
Page 39
Page 40
Page 41
Page 42
Page 43
Page 44
Page 45
Page 46
Page 47
Page 48
Page 49
Page 50
Page 51
Page 52
Page 53
Page 54
Page 55
Page 56
Page 57
Page 58
Page 59
Page 60
Page 61
Page 62
Page 63
Page 64
Page 65
Page 66
Page 67
Page 68
Page 69
Page 70
Page 71
Page 72
Page 73
Page 74
Page 75
Page 76
Page 77
Page 78
Page 79
Page 80
Page 81
Page 82
Page 83
Page 84
Page 85
Page 86
Page 87
Page 88
Page 89
Page 90
Page 91
Page 92
Page 93
Page 94
Page 95
Page 96
Page 97
Page 98
Page 99
Page 100
Page 101
Page 102
Page 103
Page 104
Page 105
Page 106
Page 107
Page 108
Page 109
Page 110
Page 111
Page 112
Page 113
Page 114
Page 115
Page 116
Page 117
Page 118
Page 119
Page 120
Page 121
Page 122
Page 123
Page 124
Page 125
Page 126
Page 127
Page 128
Page 129
Page 130
Page 131
Page 132
Page 133
Page 134
Page 135
Page 136
Page 137
Page 138
Page 139
Page 140
Page 141
Page 142
Page 143
Page 144
Page 145
Page 146
Page 147
Page 148
Page 149
Page 150
Page 151
Page 152
Page 153
Page 154
Page 155
Page 156
Page 157
Page 158
Page 159
Page 160
Page 161
Page 162
Page 163
Page 164
Page 165
Page 166
Page 167
Page 168
Page 169
Page 170
Page 171
Page 172
Page 173
Page 174
Page 175
Page 176
Page 177
Page 178
Page 179
Page 180
Page 181
Page 182
Page 183
Page 184
Page 185
Page 186
Page 187
Page 188
Page 189
Page 190
Page 191
Page 192
Page 193
Page 194
Page 195
Page 196

x

Jökull

Direct Links

If you want to link to this newspaper/magazine, please use these links:

Link to this newspaper/magazine: Jökull
https://timarit.is/publication/1155

Link to this issue:

Link to this page:

Link to this article:

Please do not link directly to images or PDFs on Timarit.is as such URLs may change without warning. Please use the URLs provided above for linking to the website.