A. Jonsson 1 (in 1593) shows that the early settlers in Iceland 

 were successful in the tillage of the ground and that laws existed 

 for the harvesting of the corn. Local names were often derived 

 from agricultural terms, »hence from the fields there are proper 

 names of certayne places .... all which are manifest takens of the 

 tillage of the ground amongst the first Islanders which also even 

 unto this day, I heare, is practised by some Inhabitants of South 

 Island but with less increase, the ground and temper of the ayre de- 

 generating from the first goodness there-of after so many ages. ...» 



Arngrim Jonsson, the contemporary of Bjorn Jonsson, evidently 

 did not share the modern view that the climate of Iceland had not 

 changed since its first colonisation in the 8th century up to his own 

 time, the end of the 16th century. In the Icelandic annals and in 

 Thoroddsen's peper »Den Gronlandska drifisen vid Island » (tidskr. 

 Ymer) we can follow the gradual deterioration of the Icelandic 

 climate. 



Thoroddsen writes: 



»The drift-ice causes the bad years in Iceland 2 . The north-coast 

 is most exposed to the ice and here it is very seldom that we do 

 not in some way or other and in some season or other, experience 

 its unpleasant neighbourhood. In the older Icelandic annals the drift- 

 ice is often mentioned, but only when it has proved specially dis- 

 astrous to the country. . . 



»Although weather conditions are often mentioned in the older 

 annals and Sagas I cannot find that the annual ice-drift to the shores 

 of Iceland is spoken of before the 13th century.... » 



In the 13th centurj^ Iceland began to get blocked by" the drift- 

 ice from Greenland. The blockade was much more severe then 

 than now; although even now the northcoast is frequently blocked 

 and sometimes, though not often, even the east-and southcoasts. 

 Owing to the influence of the Irmingercurrent the westcoast in 

 our time is nearly always free from ice. Thoroddsen enumerates 

 the worst ice-years beginning with: 



»1233 The drift-ice lay off the shore all summer. 



1260 3 Drift-ice all round Iceland so that every fjord was packed with it. 



1279 4 Very severe cold in the winter and so much ice that it was possible to 

 drive for miles out from the coast. The ice continued far into the summer and 

 from many fishing harbours it was impossible to get out to sea and fish. 



1290 — 91. Ice north of the country all summer measuring 15 ells in thickness. 

 1306 Drift-ice almost all summer by the north country. 



1320 The spring was called »the ice-spring ». Drift-ice on the east coast down 

 to Sjoa. The ice went away at Easter. 



1347 — 48 Much ice. The sea was frozen all round the land so that one could 

 ride from one headland to the next. 



1360 The drift-ice lay off the shore till 24th of August. 



1375 The drift-ice lay off the shore to the 17th of June. » 



Ice-blockades of this kind which were unknown in the Viking-age 

 have since occurred several times in every century and have naturally 

 put back the cultivation of the land. To show what an »ice-year» 

 in Iceland means I will quote the description by Thoroddsen of the 

 year 1695. 



»The ice encompassed the whole country except Ingolfsnses, which is unexampl- 

 ed in history. There were such quantities of ice in most places that the open 

 sea was invisible even from the loftiest mountainpeaks and the merchantships 

 could not land. The ice drifted from the north-country to the eastcoast and 

 thence to the south-coast. As early as in Aprilit had reached Thorlakshavn whence 

 it continued to Hitaros. On the northwest side the ice drifted past Latrabjerg 

 into the Bredebugten. In the beginning of May it was possible to ride or drive 

 outside every fjord in the north-country. » 



It is interesting to compare the series of ice-years in Iceland 

 with the description in Swedish records (f. inst. in Scriptores rerum 

 Suecicarum), of the severe winters in Scandinavia in the 12th and 

 13th centuries, when the Baltic was frozen over several times be- 

 tween Sweden, Denmark and Germany. Later on I shall collocate 

 the ice-years in Iceland and the alteration in the old direction for 

 navigation between Iceland and Greenland as described by Ivar 

 Bardsson, Stewart to the bishop of Osterbygden in Greenland 1341. 

 This description is recorded by Bjorn Jonsson (1574 — 1656) in his 

 »Gronlands Annaler ». 



The ice-conditions in Greenland are intimately connected with 

 those of Iceland. The advance of the ice out of Nordbotn in the 

 12 — 13th centuries of which Bardsson speaks proved fatal to the old 

 Norse colonies in Greenland, because it cut off the communication with 

 their mother-country. Thus the Vestbygd settlement was destroyed 

 about 1342 and the Osterbygd about 1418 5 . In discussing these cata- 

 strophes so often described I will begin by stating my own opinion 

 as to the cause of it and later discuss the facts on which my 

 theory is founded. 



B. 



The ice-conditions and climatic variations in Greenland. 



Even in the age of the Sagas and the Vikings there existed 

 an ice-bearing current on the east and northeast coasts of Green- 

 land. But the current in those days cannot be compared to the 

 present one, neither in extent nor in its importance to navigation. 

 This fact I attribute to a more vivid circulation in the Irminger Sea 

 in former days. According to the researches of the Danish Ingolf- 

 expedition, the bulk of the Gulfstream branch known as the Irminger- 

 current turns westward at the entrance to the Denmark Strait and 

 runs along the eastcoast of Greenland forming the underlayer of the 

 ice-bearing polar current. According to A. Hambergs investigation 

 in 1883 this varm underlayer has a temperature of 3° — 4°. The 

 heating from the underlayer melts the ice of the polar current and 

 the amount of driftice on the eastcoast off Cape Dan in lat. 65^° 

 will vary with the strength of the Irmingercurrent. South of Cape 

 Farewell the ice turns west and northwest collecting outside the 

 southwestern coast of Greenland (Julianehaabs Distrikt). Here 

 3. — 9 centuries ago the Icelandic colonists found an open sea. Now 

 it is blocked by ice all summer because the Irmingercurrent is too 

 weak to melt the ice before it reaches Cape Farewell. 



A small increase in the temperature of the underlayer, or a stronger 

 influx of Gulfstreamwater, or a stronger oscillation in the border- 

 stratum causing a more vivid contact of the waters of the two cur- 

 rents would scatter the drift-ice so that the neighbourhood of Cape 

 Farewell would be free from ice and the deep sounds between that 

 island and the main land open to navigation. Later we shall see 

 the importance of these sounds for the journeys of the Viking- 

 settlers. 



The formation of the coast in the lat. of Cape Dan causes the 

 drift-ice to scatter after the passage of the Denmark Sound. The 

 scattering of the ice and the action of the Irmingercurrent which 

 still in its full force crosses over from Iceland to Greenland makes 

 the neighbourhood of Angmangsalik (Cape Dan) more accessible 

 from the east than the southermost point of Greenland. 



Nordenskiold was the first in modern time to profit by this 

 when in 1883 he broke through the thin ice-layer outside Cape Dan 

 and anchored his ship »the Sophia » in King Oscar's Harbour (lat. 

 65°35 6 ). 



The stronger development of the Irmingercurrent a thousand 

 years ago brought two important consequences: 



1) The climate of Osterbygden (the eastern settlement) was 

 more temperate because the sea coast was free from ice, whereas now 

 the district of Julianehaab has an ice-bound sea in front and the 

 inland-ice behind. 



2) As the ice did not go round Cape Farewell and enter Davis Strait, 

 Baffins Bay and the Labrador-current were also relatively free from 

 ice. This again influenced the climate of New-foundland and North 

 America. It is also probable that the warm undercurrent which 

 runs through Davis Strait, like the Irmingercurrent and the rest of 

 the western Gulfstream-branches, was otherwise developed in those 

 days. In other words: that the polar-ice then melted at a higher 

 latitude than now. 



At the end of the Middle-ages a change came in these conditions, 

 which can only be explained by an alteration in the oceanic circula- 

 tion. Such changes in the oceanic circulation will of course be more 



1 Purchas, his Pilgrimes, published 1670. 



2 From 800 to 1250 Iceland seems to have had a prosperous time without calamities caused by volcanic eruptions, earthquakes, irost & ice blockades. Between 1291 

 and 1348 however a catastrophic period set in. At least 29 of these 58 years an noted for terrible catastrophes according to G. Storms .Icelandic Annals unto 1578* 

 (»halhBri micit om allt land, etc. . ») The volcanic eruption in 1300 and following years was preceded by a series of earthquakes and upheavel of volcanic .slands 

 (»elldeyar») on the Reykiana3S submarine ridge. 



3 refers probably to the following year. In Annal. Regii we read »mcclxl Hafiss umhvarfiss Island*. 



4 Also the year 1275 was an ice-year: » »Kringdi hafis nser vm allt Island» (Gottschalks Ann). 



5 The exact time cannot be determined with security. 



« Nordenskiolds intention (see p. 403 of Den andra Dicksonska expeditionen till Gronlsnd 1SS3) was, according to his own words, to follow the sailing directions of 

 Ivar Bardsson: »Steer straight westward from Iceland: there is GunnljornsMr »/ Thus Nordenskiold found the Cunnbjornskar of the Sagas which had been lost 500 years ago. 



